Fosamax is a brand-name prescription medication. It’s FDA-approved for the following uses in adults:

  • prevent or treat osteoporosis (a condition that causes brittle, weak bones) in females* who’ve gone through menopause
  • treat osteoporosis in males*
  • treat osteoporosis that’s caused by using a type of medication called glucocorticoids
  • treat Paget’s disease of bone (a condition that causes weak, soft bones)

* Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Drug details

Fosamax contains the active drug alendronate. It belongs to a class of medications called bisphosphonates. (A class of medications is a group of drugs that work in a similar way.) Fosamax works to decrease bone breakdown in your body and make your bones stronger.

Fosamax comes as 70-milligram (mg) tablets that you take by mouth, typically once a week.

It’s not known exactly how long treatment with Fosamax should last. In clinical trials, the drug was only studied in people for up to 4 years. Your doctor may have you stop taking Fosamax after 3 to 5 years.

For more information on length of use and safety, see the “Fosamax uses” section below.

What’s Fosamax Plus D?

Fosamax Plus D is a combination of Fosamax and vitamin D3. Fosamax Plus D is available in the following strengths:

  • 70 mg of Fosamax / 2,800 units of vitamin D3
  • 70 mg of Fosamax / 5,600 units of vitamin D3

Like Fosamax,* Fosamax Plus D is FDA-approved to:

  • treat osteoporosis in females† who’ve gone through menopause
  • treat osteoporosis in males†

This article focuses on Fosamax, not Fosamax Plus D. If you’d like to know more about Fosamax Plus D, talk with your doctor or pharmacist. They can recommend whether Fosamax or Fosamax Plus D might be better for your condition.

* See above for additional approved uses for Fosamax.
Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Effectiveness

For information on the effectiveness of Fosamax, see the “Fosamax uses” section below.

The Food and Drug Administration (FDA) approves prescription drugs such as Fosamax to treat certain conditions. Fosamax may also be used off-label for other conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Fosamax is FDA-approved to manage certain bone conditions, which are described in detail below.

It’s not known exactly how long treatment with Fosamax should last. In clinical trials, the drug was only studied in people for up to 4 years. It wasn’t studied as treatment for any longer than that. For this reason, your doctor may monitor your bone strength while you’re taking Fosamax. This will help your doctor to determine how long you need to continue taking the drug.

If you’re at low risk for fractures, your doctor may have you stop taking Fosamax after 3 to 5 years. But your doctor will continue to monitor your bone strength and risk of fracture after you stop taking Fosamax.

Note: Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Fosamax for treating osteoporosis

Fosamax is approved to treat osteoporosis in certain people. Specifically, the drug is approved to treat this condition in males, and in females who’ve gone through menopause.

With osteoporosis, your bones become weaker than usual and your bone density is decreased. (Bone density is a measure of how strong your bones are.) Osteoporosis causes your bones to become brittle and increases your risk of fractures.

Osteoporosis may be caused by:

  • other medical conditions, such as cancer
  • certain medications, such as prednisone
  • changes in your hormone levels

When osteoporosis occurs in females who’ve gone through menopause, it’s usually due to the decrease in estrogen that happens with menopause. When osteoporosis occurs in males, it may be due to a decrease in male hormones, such as testosterone. So, as both females and males age, their risk of osteoporosis increases.

Effectiveness for treating osteoporosis

In clinical trials, Fosamax was effective medication in treating osteoporosis. Below, we describe results from these trials.

Effectiveness in females with osteoporosis who’d gone through menopause

In trials of females with osteoporosis who’d gone through menopause, at least one new spinal fracture was reported in:

  • between 2.1% and 7.9% of females taking Fosamax 10 milligrams (mg) once daily
  • between 3.8% and 15% of females taking a placebo (a treatment no active drug)

Also in these trials, at least two new spinal fractures were reported in:

  • between 0.1% and 0.6% of females taking Fosamax 10 mg once daily
  • between 0.6% and 4.9% of females taking a placebo

A trial was also done to compare Fosamax 70 mg once weekly dosing with Fosamax 10 mg once daily dosing. This study looked at bone mineral density (BMD) in females’ spines. (BMD is a measure of how strong your bones are.)

After 1 year of treatment, spinal BMD was increased by:

  • 5.1% in females taking 70 mg of Fosamax once weekly
  • 5.4% in females taking 10 mg of Fosamax once daily

Effectiveness in males with osteoporosis

Clinical trials also looked at males with osteoporosis. Bone mineral density (BMD) was measured to assess how strong the males’ bones were.

In one trial, compared with males taking a placebo, males who took 10 mg of Fosamax daily had their BMD increase by an average of:

  • 5.3% more in the spine
  • 2.6% more in the femoral neck (the area of your thigh bone that connects into your hip)
  • 1.6% more in the total body

Another trial was done to compare Fosamax 70 mg once weekly dosing with a placebo. Compared with males taking a placebo, BMD was increased in males taking Fosamax 70 mg weekly by an average of:

  • 2.8% in the spine
  • 1.9% in the femoral neck
  • 1.2% in the total body

Fosamax for preventing osteoporosis

Fosamax is approved to prevent osteoporosis in females who’ve gone through menopause.

With osteoporosis, your bones become weaker than usual and your bone density is decreased. (Bone density is a measure of how strong your bones are.) Osteoporosis causes your bones to become brittle and increases your risk of fractures.

Osteoporosis may be caused by:

  • other medical conditions, such as cancer
  • certain medications, such as prednisone
  • changes in your hormone levels

When osteoporosis occurs in females who’ve gone through menopause, it’s usually due to the decrease in estrogen that happens with menopause. So, as females age, their risk of osteoporosis increases. Taking Fosamax can prevent osteoporosis from occurring.

Effectiveness for preventing osteoporosis

In clinical trials, Fosamax was effective in preventing osteoporosis in females who’d gone through menopause.

In the trials, bone mineral density (BMD) was measured to assess how strong the female’ bones were. The trial showed that:

  • females taking a placebo (treatment with no active drug) lost about 1% of BMD in their spine, hip, and total body, each year
  • females taking Fosamax 5 mg daily had their BMD increased by 1% to nearly 4% in their spine, hip, and total body, depending on where BMD was measured

Weekly dosing of Fosamax was also compared with daily dosing of the drug one clinical trial. In this trial, BMD of the spine was increased by:

  • 2.9% in females taking Fosamax 35 mg once weekly
  • 3.2% in females taking Fosamax 5 mg once daily

Other increases in BMD were similar in areas of the body other than the spine. This study showed BMD increases were similar, whether Fosamax was taken once daily or once weekly.

Fosamax for treating glucocorticoid-induced osteoporosis

Fosamax is approved to treat osteoporosis that’s caused by taking glucocorticoids in adults. Glucocorticoids are types of steroid medication. An example of a glucocorticoid is the drug prednisone.

With osteoporosis, your bones become weaker than usual and your bone density is decreased. (Bone density is a measure of how strong your bones are.) Osteoporosis causes your bones to become brittle and increases your risk of fractures.

Osteoporosis may also be caused by:

  • other medical conditions, such as cancer
  • changes in your hormone levels

In addition, osteoporosis can be caused by using certain medications, such as glucocorticoids. For this use, Fosamax is approved to treat people who are taking a dose of glucocorticoids that’s equal to 7.5 mg or more of prednisone each day. It’s not known if Fosamax is safe and effective in people taking a dose of glucocorticoids that’s lower than this amount.

Before starting Fosamax, people with osteoporosis that’s caused by using glucocorticoids should have low bone mineral density (BMD). (BMD is a measure of how strong your bones are.) Fosamax shouldn’t be used to treat this condition in people whose BMD isn’t low.

Effectiveness for treating glucocorticoid-induced osteoporosis

In clinical trials, Fosamax was effective in treating osteoporosis that is caused by taking glucocorticoids. In these trials, BMD of the spine was measured in people taking Fosamax and in people taking a placebo (treatment with no active drug).

The trials showed that after 2 years of treatment, BMD in the spine was increased by:

  • 3.7% more in people taking Fosamax 5 mg, compared with people taking a placebo
  • 5% more in people taking Fosamax 10 mg, compared with people taking a placebo

Studies also showed that after taking Fosamax for 2 years, new spinal fractures occurred in:

  • 0.7% of people taking Fosamax
  • 6.8% of people taking the placebo

Fosamax for treating Paget’s disease of bone

Fosamax is approved to treat Paget’s disease of bone in adults.

With Paget’s disease of bone, your body breaks down and makes new bone faster than it should. And the new bone that’s made is soft, weak, and fractures easily. Paget’s disease can also cause bone pain and bone deformities.

Fosamax is only approved to treat Paget’s disease of bone in people with certain criteria. These criteria include having:

  • levels of alkaline phosphatase (ALP)* that are at least two times higher on blood tests than they should be
  • symptoms of Paget’s disease, such as bone pain
  • a high risk of complications from Paget’s disease of bone, such as arthritis

* Your body uses ALP to help form bone. When ALP is elevated, it may mean that your body is forming bone too quickly.

Effectiveness for treating Paget’s disease of bone

In clinical trials, Fosamax was effective in treating Paget’s disease of bone. In the trials, people’s ALP levels were measured. A response to treatment was seen when people’s ALP levels either returned to normal or decreased by at least 60%.

The trials showed that:

  • about 85% of people taking Fosamax had a response to treatment
  • about 30% of people taking etidronate* had response to treatment
  • 0% of people taking a placebo (treatment with no active drug) had a response to treatment

Studies also looked at new bone formation in people with Paget’s disease who were taking Fosamax. (People with Paget’s disease usually have problems with the way that their bones form, and this can lead to deformities.) In the studies, people taking Fosamax had normal bone formation while they were taking Fosamax.

* Etidronate is medication that was used in the past to treat Paget’s disease of bone. But this drug has since been discontinued.

Fosamax and children

At this time, Fosamax isn’t approved for use in children with any condition. However, clinical studies were done to see if Fosamax could be used as a treatment in children with osteogenesis imperfecta. This genetic bone condition causes very weak, fragile bones.

However, these studies didn’t show a decrease in fractures when Fosamax treatment was compared with placebo treatment. (A placebo is a treatment with no active drug.) Also when compared with the placebo, Fosamax didn’t reduce bone pain in the children.

You should take Fosamax according to your doctor’s or healthcare professional’s instructions.

Note: If you’re taking alendronate, the generic form of Fosamax, you can also follow the instructions below for how to take Fosamax. (A generic drug is an exact copy of the active drug in a brand-name medication.)

When to take

You should take Fosamax first thing in the morning, with 6 to 8 ounces (oz) of plain water. Don’t take Fosamax with coffee, juice, mineral water, soda, or juice. Be sure to take it at least 30 minutes before you eat, drink anything besides plain water, or take any other medications.

Taking Fosamax at the same time as food, drinks, or other medications can prevent your body from properly absorbing the drug. And this could lead to the drug not working as well to treat your condition.

To help make sure that you don’t miss a dose, try setting a reminder on your phone. A medication timer may be useful, too.

Note: If you take the liquid solution form of alendronate, take your dose and then drink at least 2 oz of plain water. Follow all other instructions for taking Fosamax.

After taking Fosamax

For at least 30 minutes after you take Fosamax, you shouldn’t lie down, eat or drink anything, or take any other medications. After these 30 minutes have passed, you should continue to avoid lying down until after you eat something.

Lying down sooner than 30 minutes after your dose, especially with an empty stomach, can increase the risk of side effects in your esophagus. (The esophagus is the tube that connects your mouth to your stomach.)

For details about these possible side effects of Fosamax, see the “Fosamax side effects” section above.

Taking Fosamax with supplements

Be sure to tell your doctor about all of the medications you take, including supplements. Taking certain supplements could interfere with how well Fosamax works. For more information, see the “Fosamax interactions” section below.

While you’re taking Fosamax, your doctor may recommend that you take a calcium and vitamin D supplement. These nutrients help your body build and maintain strong bones.

Make sure to take your calcium and vitamin D supplement at least 30 minutes after you take Fosamax.

Taking Fosamax with food

You should take Fosamax when your stomach is empty, first thing in the morning. Take it with water, and don’t eat or drink anything else for at least 30 minutes afterward. This includes drinking coffee, orange juice, and carbonated water.

You should also wait at least 30 minutes after taking Fosamax before you take any other medications or supplements.

Taking Fosamax at the same time as food, drinks, or other medications can prevent your body from properly absorbing Fosamax. And this could lead to the drug not working as well to treat your condition.

For more information about taking other medications with Fosamax, see the “Fosamax interactions” section below.

Can Fosamax be crushed, split, or chewed?

You should take Fosamax tablets whole. Never chew, crush, split, or suck on Fosamax tablets. Doing these things can increase your risk of an ulcer in your esophagus. (Your esophagus is the tube that connects your mouth to your stomach.)

If you have trouble swallowing pills, talk with your doctor. They may have you try the liquid solution form of alendronate. (Alendronate is the active drug in Fosamax. It’s available in a generic form.)

How can I stop taking Fosamax?

You should always talk with your doctor before you stop taking any medications. If your doctor recommends that you stop taking Fosamax, be sure to follow their instructions for stopping. Sometimes your doctor may recommend that you stop taking Fosamax if you have side effects from the drug. Or they may recommend that you stop treatment if you’ve been taking Fosamax for a certain amount of time.

It’s not known exactly how long treatment with Fosamax should last. In clinical trials, the drug was only studied in people for up to 4 years. It wasn’t studied as treatment for any longer than that. For this reason, your doctor may monitor your bone strength while you’re taking Fosamax. This will help your doctor to determine how long you need to continue taking the drug.

If you’re at low risk for bone fracture, your doctor may have you stop taking Fosamax after 3 to 5 years. But your doctor will continue to monitor your bone strength and risk of fracture after you stop taking Fosamax.

Fosamax contains the active drug alendronate, which is also available as a generic medication. A generic medication is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the brand-name drug. Generics tend to cost less than brand-name drugs.

Fosamax only comes as a 70-milligram (mg) tablet, while alendronate comes as tablets and as a liquid solution. Alendronate tablets are available in the following strengths: 5 mg, 10 mg, 35 mg, 40 mg, and 70 mg. Alendronate liquid solution is available as a 75-milliliter (mL) bottle. Each mL of solution contains 70 mg of active drug.

Fosamax can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Fosamax. These lists don’t include all possible side effects.

For more information on the possible side effects of Fosamax, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to notify the FDA about a side effect you’ve had with Fosamax, you can do so through MedWatch.

Mild side effects

Mild side effects of Fosamax can include:*

Most of these side effects may go away within a few days or a couple of weeks. But if they become more severe or don’t go away, talk with your doctor or pharmacist.

* This is a partial list of mild side effects from Fosamax. To learn about other mild side effects, talk with your doctor or pharmacist, or view Fosamax’s Medication Guide.

Serious side effects

Serious side effects from Fosamax aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include:

  • Osteonecrosis (death of bone tissue) in your jaw bone.* Symptoms can include:
    • loose teeth
    • numbness in your jaw
    • pain or redness in your jaw area
    • being able to see your jaw bone from inside your mouth (in rare cases)
  • Fractures† of your femur (thigh bone). Symptoms can include:
    • pain in your hip, groin, or thigh
    • swelling in your hip, groin, or thigh
    • trouble moving the leg
  • Irritation of your esophagus (the tube from your mouth to your stomach) or your stomach. Symptoms can include:
    • pain when you swallow
    • ulcers (holes or sores) in the lining of the esophagus
    • bleeding in the esophagus
  • Low blood calcium levels. Symptoms can include:
    • numbness in your fingers or toes
  • Allergic reaction.*
  • Severe pain in your bones, joints, or muscles.*

* For more information on these side effects, see “Side effect details” below.
† In clinical trials, femur fractures weren’t reported as a side effect of Fosamax. However, this side effect has been reported, though rarely, since the drug came onto the market. And bone fractures have happened with other bisphosphonate drugs (the drug class that Fosamax belongs to).

How long do side effects from Fosamax last?

It depends. Certain side effects, such as heartburn or nausea, may go away after you’ve taken a few doses of Fosamax. However other side effects, such as bone pain or a low blood calcium level, may not go away after a few doses of the drug.

If you develop any side effects that are severe or bothersome to you, or that don’t go away, talk with your doctor about ways to decrease your side effects.

Side effect details

You may wonder how often certain side effects occur with this drug, or whether certain side effects pertain to it. Here’s some detail on certain side effects this drug may or may not cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Fosamax. It’s not known how many people in clinical trials had an allergic reaction to Fosamax.

Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Fosamax. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Jaw side effects

In rare cases, you may have osteonecrosis of your jaw bone while taking Fosamax. Osteonecrosis is a condition in which bone tissue dies due to lack of blood flow. Symptoms can include:

  • loose teeth
  • numbness in your jaw
  • pain or redness in your jaw area
  • exposed jaw bone (having small areas of jaw bone that show through your gums), in rare cases

It’s not known how many people experienced osteonecrosis of the jaw while taking Fosamax in clinical trials. One medical records review of people who were prescribed the drug found that osteonecrosis in the jaw happened in 4% of people taking Fosamax.

You may have a higher risk of osteonecrosis of the jaw while taking Fosamax if you:

  • take Fosamax for a long time (the longer you take Fosamax, the higher your risk)
  • have an invasive dental procedure, such as getting a tooth removed or a dental implant
  • have cancer
  • take certain medications, such as chemotherapy drugs
  • difficulty maintaining oral hygiene
  • have certain conditions, including:
    • blood disorders, such as anemia (low level of red blood cells)
    • preexisting dental conditions
  • wear dentures that don’t fit properly

If you’re taking Fosamax and any of these risk factors apply to you, talk with your doctor. If you must have a dental procedure while taking Fosamax, tell your doctor first. Your doctor may have you stop taking Fosamax temporarily, to help lower your risk of jaw side effects.

Hair loss

Hair loss may occur while you’re taking Fosamax. Although hair loss wasn’t seen in clinical trials, it has been reported since the drug was approved by the FDA and released onto the market. However, it isn’t known exactly how many people have had this side effect since Fosamax was approved.

If you have hair loss while you’re taking Fosamax, talk with your doctor. They may recommend ways to decrease this side effect or a different medication to treat your condition.

Joint, bone, or muscle pain

You may develop pain in your joints, bones, or muscles while you’re taking Fosamax.

These types of pain may develop right away, as soon as 1 day after you start taking Fosamax. Or they may develop up to a few months after starting Fosamax.

In clinical trials, joint, bone, or muscle pain occurred most often in females who’d been through menopause and were taking Fosamax to treat osteoporosis. In the trials, these types of pain occurred in:

  • 0.4% to 4.1% of females taking Fosamax
  • 0.3% to 2.5% of females taking a placebo (treatment with no active drug)

If you develop pain that’s severe or makes you unable to move, talk with your doctor right away. Your doctor may recommend that you stop taking Fosamax and try a different medication to treat your condition. Your doctor may also recommend certain tests to check for fractures.

Keep in mind that severe pain or trouble moving that affects your thigh or groin area could be a sign of a thigh bone fracture. (For more information about this, see the “Serious side effects” list above.)

* Sex and gender exist on spectrums. Use of the term “female” in this article refers to sex assigned at birth.

Weight gain (not a side effect)

Weight gain isn’t a side effect that you should have while taking Fosamax. In clinical trials, weight gain didn’t occur in people taking Fosamax.

However, peripheral edema (swelling in your arms or legs) has been reported by some people since Fosamax was approved by the FDA and released onto the market. Peripheral edema may cause weight gain, but Fosamax itself doesn’t directly cause weight gain as a side effect.

It’s not known how many people have had peripheral edema while taking Fosamax since the drug was released onto the market.

If you gain weight while you’re taking Fosamax, talk with your doctor. They may be able to help you determine what’s causing the weight gain. Your doctor can also help create a weight management plan that’s healthy for you.

The Fosamax dosage your doctor prescribes will depend on several factors. These include:

  • the type and severity of the condition you’re using Fosamax to treat
  • other medical conditions you may have

Your doctor may adjust your dose over time to reach the amount that’s right for you. They will ultimately prescribe the smallest dosage that provides the desired effect.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.

Note: Sex and gender exist on spectrums. Use of the term “female” in this article refers to sex assigned at birth.

Drug forms and strengths

Fosamax comes as 70-milligram (mg) tablets that you take by mouth. This drug should be taken first thing in the morning, before you take other medications or consume any foods or drinks.

Fosamax is also available as the generic drug alendronate. (A generic drug is an exact copy of the active drug in a brand-name medication.)

Alendronate comes as tablets and as a liquid solution. Both of these forms are taken by mouth. Alendronate tablets are available in the following strengths: 5 mg, 10 mg, 35 mg, 40 mg, and 70 mg. Alendronate liquid solution is available as a 75-milliliter (mL) bottle. Each mL of solution contains 70 mg of active drug.

In the past, a liquid solution of Fosamax was available, as well as other strengths of Fosamax tablets. However, the manufacturer of Fosamax no longer makes these products.

Dosage for treating osteoporosis

Fosamax is approved to treat osteoporosis in females who’ve gone through menopause. The drug is also approved to treat osteoporosis in males. In these cases, the typical dosage of Fosamax is one 70-mg tablet taken once a week.

Another treatment option for these conditions is the generic form of Fosamax, called alendronate. To treat osteoporosis, alendronate can be taken as either the 70-mg tablet or the 75-mL bottle of 70-mg oral solution, once weekly. It can also be taken as a 10-mg tablet once daily.

Dosage for preventing osteoporosis

Fosamax is approved to help prevent osteoporosis in females who’ve gone through menopause. For this purpose, you’ll need to take the generic version of Fosamax, alendronate. Fosamax only comes as a 70-mg tablet, while alendronate tablets come in the smaller doses that are needed for this use.

To help prevent osteoporosis, alendronate tablets can be taken as either:

  • 35 mg once per week
  • 5 mg once per day

Dosage for treating glucocorticoid-induced osteoporosis

Fosamax is approved to treat osteoporosis that’s caused by a type of medication called glucocorticoids. For this purpose, you’ll need to take the generic version of Fosamax, alendronate. Fosamax only comes as a 70-mg tablet, while alendronate tablets come in the smaller doses that are needed for this use.

To treat osteoporosis that’s due to glucocorticoid use, the recommended dosage of alendronate tablets may be either:

  • 5 mg once per day
  • 10 mg once per day, if you’re a woman who’s gone through menopause and you’re not taking estrogen

Dosage for treating Paget’s disease of bone

Fosamax is approved to treat Paget’s disease of bone. For this purpose, you’ll need to take the generic version of Fosamax, which is called alendronate. This is because Fosamax only comes as a 70-mg tablet, while alendronate tablets comes in the smaller doses that are needed for this use.

The recommended dosage of alendronate for treating Paget’s disease of bone is a 40-mg tablet taken once per day, for 6 months.

After 6 months of treatment, you’ll stop taking alendronate. Then your doctor will continue to monitor your blood alkaline phosphatase (ALP)* levels. If your ALP levels increase above a normal level, your doctor may have you take alendronate again. Your doctor may also have you take alendronate again if your first treatment doesn’t reduce your ALP levels enough.

If you have questions about how often alendronate can be used to treat your Paget’s disease of bone, talk with your doctor.

* Your body uses ALP to help form bone. When ALP is elevated, it may mean that your body is forming bone too quickly.

What if I miss a dose?

If you miss a Fosamax or alendronate dose, take the dose the next morning. (Keep in mind that Fosamax and alendronate should be taken first thing in the morning.) Don’t take your missed dose later in the day. And, don’t take two doses in the same day.

If you take Fosamax or alendronate once per week, take your missed dose and then go back to taking your dose once a week as told by your doctor.

If you have questions about when to take your next dose after you miss a dose, talk with your doctor or pharmacist. They can recommend the best time to take your next dose.

To help make sure you don’t miss a dose, try setting a reminder on your phone. A medication timer may be useful, too.

Will I need to use this drug long term?

It depends on why you’re taking Fosamax or alendronate.

For example, if you’re taking alendronate to treat Paget’s disease of bone, you’ll likely take the drug for 6 months. Then your doctor will evaluate your symptoms and test your blood for a period of 6 months to determine if you need another round of treatment.

However, if you’re taking Fosamax or alendronate to treat or prevent osteoporosis, you can take the drug for a longer period of time. If you’re at low risk for bone fracture, your doctor may have you stop taking Fosamax after 3 to 5 years.

It’s not known exactly how long treatment with Fosamax should last. In clinical trials, the drug was only studied in people for up to 4 years. It wasn’t studied as treatment for any longer than that. For this reason, your doctor may monitor your bone strength while you’re taking Fosamax. This will help your doctor to determine how long you need to continue taking the drug.

Other drugs are available that can treat your condition. Some may be a better fit for you than others. If you’re interested in finding an alternative to Fosamax, talk with your doctor. They can tell you about other medications that may work well for you.

Note: Some of the drugs listed here are used off-label to treat these specific conditions. Off-label use is when a drug that’s approved to treat one condition is used to treat a different condition.

Alternatives for osteoporosis

Examples of other drugs that may be used to treat or prevent osteoporosis include:

  • risedronate (Actonel)
  • ibandronate (Boniva)
  • zoledronic acid (Reclast)
  • raloxifene (Evista)
  • denosumab (Prolia, Xgeva)
  • teriparatide (Forteo)
  • abaloparatide (Tymlos)

Alternatives for Paget’s disease of bone

Examples of other drugs that may be used to treat Paget’s disease of bone include:

  • risedronate (Actonel, Atelvia)
  • ibandronate (Boniva)
  • pamidronate (Aredia)
  • zoledronic acid (Reclast)

You may wonder how Fosamax compares with other medications that are prescribed for similar uses. Here we look at how Fosamax and Prolia are alike and different.

Ingredients

Fosamax contains the active drug alendronate. Prolia contains the active drug denosumab.

Fosamax and Prolia belong to different classes of medications. (A class of medications is a group of drugs that work in a similar way.) The medications work slightly differently in the body.

Uses

Here is a list of conditions that the Food and Drug Administration (FDA) has approved Fosamax and Prolia to treat.

Both Fosamax and Prolia are FDA-approved to:

  • treat osteoporosis (a condition that causes brittle, weak bones) in males*
  • treat osteoporosis that’s caused by a type of medication called glucocorticoids

Fosamax is also FDA-approved to:

Prolia is also FDA-approved to:

  • treat osteoporosis in females who’ve gone through menopause and have a high risk for fractures
  • treat bone loss in males using certain prostate cancer treatments
  • treat bone loss in females using certain breast cancer treatments, such as anastrozole (Arimidex)

Fosamax and Prolia work to decrease bone breakdown in your body and make your bones stronger.

* Sex and gender exist on spectrums. Use of the terms “male” and “female” in this article refers to sex assigned at birth.

Drug forms and administration

Fosamax comes as tablets that are taken by mouth, typically once a week. It’s typically taken for up to 3 to 5 years.

Prolia is available as a solution that’s injected under the skin (called a subcutaneous injection) once every 6 months. This injection needs to be done by a healthcare professional, at their office or clinic. Unlike Fosamax, Prolia doesn’t have a limit on its length of use.

Alendronate, the generic form of Fosamax, comes as tablets or as a liquid solution that you take by mouth. You may take alendronate daily or weekly, depending on your dose and why you’re taking the drug. (For more information, see the “Fosamax dosage” section above.)

Side effects and risks

Fosamax and Prolia both contain medications that are used to treat osteoporosis. Therefore, these medications can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with Fosamax, with Prolia, or with both drugs (when taken individually).

Serious side effects

These lists contain examples of serious side effects that can occur with Fosamax, with Prolia, or with both drugs (when taken individually).

  • Can occur with Fosamax:
    • irritation in your stomach or esophagus (the tube from your mouth to your stomach)
  • Can occur with Prolia:
    • serious infections, such as skin infections
    • skin reactions, such as a serious rash
    • your body taking an unusually long time to make new bone
  • Can occur with both Fosamax and Prolia:
    • fractures of your femur (thigh bone)
    • severe pain in your bones, joints, or muscles

Effectiveness

Fosamax and Prolia have some different FDA-approved uses, but they are both used to:

  • treat osteoporosis in certain females* who’ve gone through menopause
  • treat osteoporosis in males*
  • treat osteoporosis that’s caused by a type of medication called glucocorticoids

The use of Fosamax and Prolia in treating these kinds of osteoporosis hasn’t been directly compared in clinical studies. But in separate studies, both Fosamax and Prolia were shown to be effective for their approved uses.

In addition, studies have compared treatment with Prolia to that of alendronate, which is the generic form of Fosamax. (A generic drug is an exact copy of the active drug in a brand-name medication.)

In a 2019 Danish study, people took either alendronate or Prolia to treat their osteoporosis. The study showed that the risk of fracture was about the same when taking either drug. Over the course of 3 years:

  • 3.7% of people taking Prolia had a hip fracture
  • 3.1% of people taking alendronate had a hip fracture
  • 9% of people taking either Prolia or Fosamax had any type of bone fracture

In addition, in a 2009 international study, females who had been through menopause took either alendronate or Prolia to treat their osteoporosis. The females’ bone mineral density (BMD)† was measured in their hip after 12 months of treatment. In this study, BMD increased by 3.5% in females taking Prolia, compared with 2.6% in females taking alendronate.

* Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.
† BMD is a measurement of how strong your bones are.

Costs

Fosamax costs significantly less than Prolia. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Fosamax and Prolia are both brand-name drugs. There is currently a generic form of Fosamax called alendronate. Generic medications usually cost less than the brand name forms.

There is no generic form of Prolia available at this time.

You may wonder how Fosamax compares with other medications that are prescribed for similar uses. Here we look at how Fosamax and Boniva are alike and different.

Ingredients

Fosamax contains the active drug alendronate, while Boniva contains the active drug ibandronate.

Fosamax and Boniva belong to a class of medications called bisphosphonates. (A class of medications is a group of drugs that work in a similar way.)

Fosamax is available as the generic drug alendronate. And Boniva is available as the generic drug ibandronate. (A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug.)

Uses

Here is a list of conditions that the Food and Drug Administration (FDA) has approved Fosamax and Boniva to treat.

Both Fosamax and Boniva are FDA-approved to treat osteoporosis in females* who’ve gone through menopause. Osteoporosis is a condition that causes brittle, weak bones.

Fosamax is also FDA-approved to:

  • prevent osteoporosis in females who’ve gone through menopause
  • treat osteoporosis in males*
  • treat osteoporosis that’s caused by a type of medication called glucocorticoids
  • treat Paget’s disease of bone (a condition that causes weak, soft bones)

Fosamax and Boniva work to decrease bone breakdown in your body and make your bones stronger.

* Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Drug forms and administration

Fosamax comes as tablets that are taken by mouth, typically once a week.

The generic form of Fosamax, alendronate, comes as tablets and as a liquid solution. Both forms of alendronate are taken by mouth. You may take alendronate daily or weekly, depending on your dose and why you’re taking the drug.

Boniva and its generic form, ibandronate, come as tablets that are taken by mouth, typically once a month. Boniva and ibandronate also come as a liquid solution that’s given by an injection into your vein (called an intravenous injection) every 3 months. This injection needs to be done by a healthcare professional, at their office or clinic.

Both Fosamax and Boniva are typically taken for up to 3 to 5 years.

Side effects and risks

Fosamax and Boniva both contain medications to treat osteoporosis in postmenopausal females. Therefore, these medications can cause very similar side effects, but some different ones as well. Below are examples of these side effects.

Mild side effects

These lists contain up to 10 of the most common mild side effects that can occur with Fosamax, with Boniva, or with both drugs (when taken individually).

Serious side effects

These lists contain examples of serious side effects that can occur with Fosamax, with Boniva, or with both drugs (when taken individually).

  • Can occur with Fosamax:
    • no unique serious side effects
  • Can occur with Boniva:
    • kidney damage*
  • Can occur with both Fosamax and Boniva:
    • unusual fractures of your thigh bone, such as fractures that happen without a known cause
    • irritation of your stomach or esophagus (the tube from your mouth to your stomach)†
    • low levels of calcium in your blood
    • severe bone, joint, or muscle pain

* Females who used the injectable form of Boniva in clinical trials had this side effect. (Note: Sex and gender exist on spectrums. Use of the term “female” in this article refers to sex assigned at birth.)
† People who took Fosamax or Boniva by mouth in clinical trials had this side effect.

Effectiveness

Fosamax and Boniva have some different FDA-approved uses, but they’re both used to treat osteoporosis in females* who’ve gone through menopause.

The use of Fosamax and Boniva tablets in treating osteoporosis has not been directly compared in clinical studies. However, a 2007 study directly compared alendronate and ibandronate tablets in treating osteoporosis in females who’ve gone through menopause. (Alendronate is the generic form of Fosamax. And ibandronate is the generic form of Boniva.)

In this trial, females took either alendronate once a week by mouth or ibandronate once a month by mouth. The results showed that both generic drugs were effective at treating osteoporosis in this group of females. After 1 year of treatment, bone mineral density (BMD)† was increased by:

  • 5.1% in the spine of females taking ibandronate once monthly
  • 5.8% in the spine of females taking alendronate once weekly
  • 2.9% in the hip of females taking ibandronate once monthly
  • 3% in the hip of females taking alendronate once weekly

* Sex and gender exist on spectrums. Use of the term “female” in this article refers to sex assigned at birth.
† BMD is a measurement of how strong your bones are.

Costs

Fosamax tablets costs significantly less than Boniva tablets. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Fosamax and Boniva are both brand-name drugs. There are currently generic forms of both drugs. The generic form of Fosamax is called alendronate. The generic form of Boniva is called ibandronate. Brand-name medications usually cost more than generics.

Here are answers to some frequently asked questions about Fosamax.

Will Fosamax cure my condition?

No, Fosamax doesn’t cure osteoporosis or Paget’s disease of bone. In fact, there’s currently no cure for either of these conditions. However, treatments such as Fosamax may help relieve symptoms and keep these conditions from getting worse.

For example, if you have osteoporosis, Fosamax can reduce your risk of fractures and increase your bone mineral density (BMD). BMD is a measurement of how strong your bones are.

Also, Fosamax continues to work to decrease your bone breakdown even after you stop taking it. This means your symptoms of osteoporosis or Paget’s disease may continue to decrease even after you stop treatment.

Will stopping Fosamax cause side effects?

No, you shouldn’t have side effects when you stop taking Fosamax.

Stopping other medications that treat or prevent osteoporosis, such as Prolia, may cause side effects. These side effects can include bone loss and an increased risk of fractures. However, stopping Fosamax shouldn’t cause these or other side effects.

If you seem to be having side effects after stopping Fosamax, call your doctor.

Does Fosamax cause cancer?

It’s not known if Fosamax increases your risk of cancer. Cancer wasn’t reported as a side effect in clinical trials of Fosamax. However, the Food and Drug Administration (FDA) has been reviewing clinical studies to see if there’s a link between medications such as Fosamax and cancer of the esophagus. (The esophagus is the tube that connects your mouth to your stomach.)

Fosamax belongs to a class of medications called bisphosphonates.* (A class of medications is a group of drugs that work in a similar way.)

One study done in the United Kingdom in 2010 showed that people taking bisphosphonates* by mouth didn’t have an increased risk of esophageal cancer. However, another 2010 study in the United Kingdom showed that the risk of esophageal cancer was about doubled in people who filled their bisphosphonate prescription at least 10 times. This was in comparison to people who filled their bisphosphonate prescription between 1 and 9 times.

The risk of esophageal cancer was also about doubled in people who took a bisphosphonate medication for at least 3 years. And this was in comparison to people who didn’t take a bisphosphonate medication.

It’s important to note that cancer of the esophagus is very rare, especially in females.†

At this time, the FDA hasn’t determined that taking biphosphates, such as Fosamax, by mouth increases your risk of cancer. If you’re concerned about your cancer risk or if you have questions, talk with your doctor.

* Biphosphonate drugs work to decrease bone breakdown in your body and make your bones stronger.
Sex and gender exist on spectrums. Use of the term “female” in this article refers to sex assigned at birth.

Can I use the supplement strontium instead of Fosamax?

While strontium may sometimes be used as an alternative to Fosamax, there’s very little evidence in the United States that strontium is safe and effective for osteoporosis treatment. This is because very few clinical trials have been done to determine if strontium can be used for osteoporosis.

Strontium is a supplement that’s similar to calcium that may help strengthen your bones. In the United States, strontium is available as strontium citrate and strontium chloride. These names refers to the form of salt used to make each strontium supplement.

Strontium ranelate is a form of strontium that’s available in Europe, but not in the United States. This drug used to be used for osteoporosis treatment. But, in 2014, the European Medicine Agency’s Pharmacovigilance Risk Assessment Committee (PRAC) recommended that strontium ranelate no longer be used for osteoporosis. After reviewing studies in which strontium ranelate was used to treat osteoporosis, the drug was found to increase the risk of heart attack and blood clots.

In 2019, strontium ranelate became available in the United Kingdom by prescription only. And people taking it must be monitored by their doctor during treatment.

If you have questions about strontium supplements, talk with your doctor about the best treatment options for you.

Can I use Fosamax if I’m taking thyroid medication?

Yes, if your doctor recommends, you can take Fosamax while you’re taking thyroid medication. There aren’t any known interactions between Fosamax and thyroid medications, such as Synthroid (levothyroxine). This means that Fosamax doesn’t affect how thyroid medications work in your body, and vice versa.

Fosamax and thyroid medications should both be taken in the morning when your stomach is empty. But you should take Fosamax before you take your thyroid medication.

Specifically, you should take Fosamax at least 30 minutes before you eat, drink, or take any other medications. After you take Fosamax, wait 30 minutes. Then take your thyroid medication and wait another 30 to 60 minutes before eating breakfast.

For details about how to take Fosamax, see the “How to take Fosamax” section below. And for more information about medications that can interact with Fosamax, see the “Fosamax interactions” section below.

Can I stop taking Fosamax ‘cold turkey’?

It depends on your doctor’s recommendation. Always talk with your doctor before you stop taking any medications.

Stopping a drug “cold turkey” means that you suddenly stop taking the drug. Another way to stop taking a medication is to slowly reduce your dosage over time, with your doctor’s help. Gradually reducing your dosage helps your body adjust to the change.

Sometimes your doctor may recommend that you stop taking Fosamax “cold turkey.” However, always discuss stopping medications with your doctor before actually doing so.

Is Fosamax safe to take for older adults?

Yes, in general, Fosamax is safe for older adults to take.

In clinical trials, 37% to 70% of people taking Fosamax were ages 65 years old or older. Fosamax was found to be just as safe for older adults as it was for younger adults. However, in some cases, older adults may be more sensitive to the medication and may have a higher risk of side effects.

If you have concerns about taking Fosamax given your age, talk with your doctor.

Before taking Fosamax, talk with your doctor about your health history. Fosamax may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • Trouble swallowing. If you have trouble swallowing pills or if you’re at risk for aspiration, talk with your doctor. Taking Fosamax tablets may be dangerous in these cases. This is because if the medication begins to dissolve in your mouth or throat, it may increase your risk of an ulcer in your esophagus. If you have trouble swallowing pills, your doctor may recommend the liquid solution form of alendronate. (Alendronate is the active drug in Fosamax.) If you’re at risk for aspiration, your doctor may recommend a medication other than Fosamax to treat your condition.
  • Esophagus or stomach problems, including problems with digestion. If you have a condition that affects your esophagus or stomach, you may have a higher risk of digestive side effects after taking Fosamax. These side effects may include an ulcer in your esophagus or bleeding in your stomach, either of which can cause your stool to look black or tar-like. Make sure to tell your doctor about any other medical conditions that you have before you start taking Fosamax.
  • Low calcium level in your blood. You shouldn’t take Fosamax if you have a low blood calcium level. This is because Fosamax may further lower your blood calcium. Your doctor may have you take a calcium supplement to raise your calcium levels before you start taking Fosamax. Talk with your doctor about treating your low blood calcium before you start taking Fosamax.
  • Plans for dental surgery or tooth removal. While taking Fosamax, if you must have a dental procedure, such as a tooth extraction, tell your doctor first. Your doctor may have you stop taking Fosamax temporarily. This is because Fosamax and dental procedures can both increase your risk of osteonecrosis (death of bone tissue) in your jaw bone.
  • Kidney problems, such as chronic kidney disease. If you have kidney problems or you’re on dialysis treatment, talk with your doctor before starting Fosamax. Fosamax is removed from your body by your kidneys. If your kidneys aren’t functioning as well as they should be, the drug may build up in your body. And this can increase your risk of side effects. Depending on how well your kidneys are working, your doctor may recommend a medication other than Fosamax to treat your condition.
  • Trouble absorbing minerals. If you have malabsorption syndrome, talk with your doctor before you start taking Fosamax. Fosamax and malabsorption syndrome both increase your risk of low blood calcium levels, which can become dangerous. Your doctor will recommend an appropriate treatment for your condition.
  • Inability to stay upright for 30 minutes. If you’re unable to sit up or stand for about 30 minutes at a time, you shouldn’t take Fosamax. This is because lying down during the first 30 minutes after you’ve taken Fosamax can increase your risk of ulcers in your esophagus. If you can’t remain upright for at least 30 minutes, talk with your doctor about medications other than Fosamax that can be used to treat your condition.
  • Allergic reaction. If you’ve had an allergic reaction to Fosamax or any of its ingredients, you shouldn’t take Fosamax. Talk with your doctor about other medications that could help treat your condition.
  • Pregnancy. Fosamax shouldn’t be taken during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor before starting Fosamax. For more information, see the “Fosamax and pregnancy” section below.
  • Breastfeeding. It’s not known if Fosamax is safe to take while breastfeeding. If you’re breastfeeding, talk with your doctor before taking Fosamax. For more information, see the “Fosamax and breastfeeding” section below.

Note: For more information about the potential negative effects of Fosamax, see the “Fosamax side effects” section above.

There aren’t any known interactions between Fosamax and alcohol. However, chronic (long-lasting) excessive alcohol use may have a negative effect on your bones, and Fosamax is used to treat certain bone conditions.

According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, alcohol use may increase your risk of developing osteoporosis. And if you have osteoporosis, drinking alcohol may worsen the condition. This is because alcohol can affect how your body uses calcium and vitamin D, which are nutrients your body uses to build and maintain strong bones.

Alcohol can also cause changes in hormone levels in males* and females.* In males, alcohol may decrease testosterone. And in females, alcohol may decrease estrogen. These hormonal changes also increase your risk of osteoporosis.

In addition, keep in mind that you should always wait at least 30 minutes after taking Fosamax before having drinks, foods, or other medications. This includes consuming alcohol.

If you drink alcohol, talk with your doctor about whether it’s safe to drink it while you’re taking Fosamax.

* Sex and gender exist on spectrums. Use of the terms “male” and “female” in this article refers to sex assigned at birth.

Fosamax can interact with several other medications. It can also interact with certain supplements as well as certain foods.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

It’s important to note that Fosamax should be taken on an empty stomach, first thing in the morning. Fosamax should be taken at least 30 minutes before any other medications, foods, or drinks. This is important to do even if a substance isn’t known to interact with Fosamax.

Taking Fosamax at the same time as food, drinks, or other medications can prevent your body from properly absorbing Fosamax. And this could lead to the drug not working as well to treat your condition.

Fosamax and other medications

Below are some of the medications that can interact with Fosamax. This section doesn’t contain all of the drugs that may interact with Fosamax.

Before taking Fosamax, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Fosamax and antacids

Antacids should be taken at least 30 minutes after you’ve taken Fosamax. This is because antacids decrease the amount of Fosamax that your body can absorb.

Examples of antacids include:

  • calcium carbonate (Tums, Alka-Seltzer)
  • magnesium hydroxide (Milk of Magnesia)
  • aluminum hydroxide/magnesium hydroxide/simethicone (Maalox, Mylanta)
  • calcium hydroxide/magnesium hydroxide (Rolaids)

If you take antacids, tell your doctor before you start taking Fosamax.

Fosamax and aspirin

Taking aspirin while you’re using Fosamax may increase your risk of certain side effects from the drugs.

For example, in clinical trials, people taking aspirin with more than 10 milligrams (mg) of Fosamax per day had an increased risk of digestive side effects. These side effects included irritation of the stomach and intestines, heartburn, and nausea. However, this increased risk was not seen in people who took 10 mg or less of Fosamax per day.

Before taking Fosamax, talk with your doctor about any other medications that you take. If you take aspirin, your doctor may recommend a medication other than Fosamax to treat your condition.

Fosamax and nonsteroidal anti-inflammatory drugs

If you take nonsteroidal anti-inflammatory drugs (NSAIDs) while you’re taking Fosamax, your doctor may monitor you more often than usual. Examples of NSAIDs include:

Both Fosamax and NSAIDs can cause irritation in your digestive tract. (The digestive tract refers to the parts of the body involved in eating and digesting foods and liquids.) This irritation may increase your risk of digestive side effects from Fosamax and NSAIDs, such as nausea or belly pain.

However, one clinical trial found that people taking Fosamax and an NSAID didn’t have an increased risk of digestive side effects. (This was in comparison with people taking a placebo, which is a treatment with no active drug.)

Taking NSAIDs and Fosamax may or may not increase your risk of side effects. But your doctor may monitor you more often during treatment just in case you have increased side effects.

Fosamax and herbs and supplements

Using certain supplements with Fosamax could make Fosamax less able to treat your condition. Below, we describe a type of supplement that may interact with Fosamax in this way.

To be safe, talk with your doctor or pharmacist before you use any herbs or supplements while you’re taking Fosamax.

Fosamax with calcium and vitamin D

Your doctor may recommend that you take a calcium and vitamin D supplement while you’re taking Fosamax. These nutrients help your body build and maintain strong bones.

But keep in mind that you should take any supplements at least 30 minutes after taking Fosamax. And only take a calcium and vitamin D supplement if your doctor recommends it.

Fosamax and foods or drinks

You should take Fosamax at least 30 minutes before consuming any food, drinks, or other medications. Taking Fosamax with these other substances can prevent your body from properly absorbing Fosamax. And this could lead to the drug not working as well to treat your condition.

Taking Fosamax with a beverage other than plain water can decrease how much Fosamax your body absorbs. This includes drinks such as coffee, orange juice, and carbonated water, In fact, clinical trials have shown that drinking coffee or orange juice with Fosamax can decrease Fosamax absorption by about 60%.

Fosamax is a brand-name prescription medication. It’s FDA-approved for the following uses in adults:

  • prevent or treat osteoporosis (a condition that causes brittle, weak bones) in females* who’ve gone through menopause
  • treat osteoporosis in males*
  • treat osteoporosis that’s caused by using a type of medication called glucocorticoids
  • treat Paget’s disease of bone (a condition that causes weak, soft bones)

* Sex and gender exist on spectrums. Use of the term “female” and “males” in this article refers to sex assigned at birth.

For more information about Fosamax’s approved uses, see the “Fosamax uses” section above.

Fosamax belongs to a class of medications called bisphosphonates. (A class of medications is a group of drugs that work in a similar way.)

Fosamax works by stopping the activity of osteoclasts (cells that break down your bone tissue). By preventing these cells from working, Fosamax increases your bone density and strength. This lowers your risk of fractures.

How long does it take to work?

Fosamax begins working after you take your first dose. However, you may not notice it working, or it may take time to notice the effects of the medication. This is because Fosamax works to decrease your bone breakdown over time.

Eventually, Fosamax can make your bones stronger and improve your bone density. Bone density is a measurement of how strong your bones are. Your doctor may check your bone density while you’re taking Fosamax to make sure that the drug is working for you.

Fosamax is used to treat certain kinds of osteoporosis, as well as Paget’s disease of bone. Fosamax works to improve bone strength by decreasing bone breakdown in your body.

Your doctor may recommend that you take a calcium and vitamin D supplement while you’re taking Fosamax. These nutrients help your body build and maintain strong bones. A supplement may be especially important if you don’t get enough calcium or vitamin D in your diet.

You should only take a supplement while you’re taking Fosamax if your doctor recommends it for you. And be sure to take any supplements at least 30 minutes after you’ve taken Fosamax. This is important to do to ensure that your body absorbs Fosamax.

Note: Fosamax Plus D, a combination of Fosamax and vitamin D3, may be prescribed to treat osteoporosis instead of Fosamax in some cases. If you have questions about whether Fosamax or Fosamax Plus D is better for treating your condition, talk with your doctor.

As with all medications, the cost of Fosamax can vary. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Before approving coverage for Fosamax, your insurance company may require you to get prior authorization. This means that your doctor and insurance company will need to communicate about your prescription before the insurance company will cover the drug. The insurance company will review the prior authorization request and decide if the drug will be covered.

If you’re not sure if you’ll need to get prior authorization for Fosamax, contact your insurance company.

Financial and insurance assistance

If you need financial support to pay for Fosamax, or if you need help understanding your insurance coverage, help is available.

Medication Assistance Tool provides lists of programs that may help to lower the cost of Fosamax. For more information and to find out if you’re eligible for support, visit the organization’s website.

Generic version

Fosamax is available as the generic drug alendronate. A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. And generics tend to cost less than brand-name drugs.

If you’re interested in using alendronate instead of Fosamax, talk with your doctor. They may recommend that you use one of the forms rather than the other. You’ll also need to check your insurance plan, as your plan may only cover one form of the medication.

Fosamax shouldn’t be taken during pregnancy.

There aren’t any studies of Fosamax use in humans during pregnancy. However, animal studies showed that Fosamax can increase the risk of death for a pregnant female and her fetus. Studies showed that Fosamax lowered body weight in fetuses and increased the risk of miscarriage. Because of this risk seen in animal studies, Fosamax shouldn’t be taken during human pregnancies.

If you’re pregnant or planning to become pregnant, talk with your doctor. They may recommend a different medication for you.

Fosamax shouldn’t be taken during pregnancy. If you’re sexually active and you or your partner can become pregnant, talk with your doctor about your birth control needs. Your doctor can recommend whether you need to use birth control while you’re taking Fosamax.

For more information about taking Fosamax during pregnancy, see the “Fosamax and pregnancy” section above.

It’s not known if Fosamax is safe to take while breastfeeding. It’s also not known if Fosamax passes into human breast milk or what effect the drug may have on a child who’s breastfed.

If you’re breastfeeding, talk with your doctor before taking Fosamax.

Using more than the recommended dosage of Fosamax can lead to serious side effects.

Do not use more Fosamax than your doctor recommends.

Overdose symptoms

Symptoms of an overdose can include:

  • low blood calcium level, which can cause heart problems such as heart failure or low blood pressure
  • low blood phosphate level, which can cause bone problems or muscle weakness
  • upset stomach
  • heartburn
  • esophagitis (inflammation or irritation in your esophagus), which can cause problems such as trouble swallowing
  • an ulcer in your esophagus, which can cause chest pain or pain when swallowing

What to do in case of overdose

If you think you’ve taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or your local emergency number, or go to the nearest emergency room right away.

When you get Fosamax from the pharmacy, the pharmacist will add an expiration date to the label on the bottle or box. This date is typically 1 year from the date they dispensed the medication.

The expiration date helps guarantee that the medication is effective during this time. The current stance of the Food and Drug Administration (FDA) is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk with your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication.

Fosamax tablets should be stored at a room temperature of 59°F to 86°F (15°C to 30°C). They should be kept in a tightly sealed container away from light. Avoid storing this medication in areas where it could get damp or wet, such as bathrooms.

Disposal

If you no longer need to take Fosamax and have leftover medication, it’s important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

This article provides several useful tips on medication disposal. You can also ask your pharmacist for information on how to dispose of your medication.

The following information is provided for clinicians and other healthcare professionals.

Indications

Fosamax is indicated to:

  • treat or prevent osteoporosis in postmenopausal females*
  • treat osteoporosis in males*
  • treat glucocorticoid-induced osteoporosis in adults taking the equivalent of 7.5 milligrams (mg) of prednisone daily
  • treat Paget’s disease of bone in adults with any of the following situations:
    • an alkaline phosphatase at least two times the normal value
    • symptomatic Paget’s disease of bone
    • low bone mineral density

* Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Of note, Fosamax has not been studied beyond 4 years of use. It is not known if the drug is safe and effective after 4 years of treatment. Therefore, it is best to reevaluate Fosamax treatment regularly.

After 3 to 5 years of treatment, reevaluate people at low risk for fracture, and consider discontinuing treatment. However, even after stopping treatment, people should still be monitored.

Administration

Fosamax is available as a tablet. The brand-name medication is only available as the 70-mg tablet that can be taken once weekly. However, alendronate, the generic form of Fosamax, is available as a tablet that comes in 5 mg, 10 mg, 35 mg, 40 mg, and 70 mg. Alendronate is also available as a 70-mg/75-mL bottle of liquid solution.

Fosamax tablets should be taken as a whole tablet in the morning on an empty stomach. The drug should be taken at least 30 minutes before any other food, drink, or medications to avoid decreased absorption of the Fosamax. After taking, people should remain upright in either a sitting or standing position for at least 30 minutes to avoid the risk of esophageal ulceration. They should also eat before lying down.

Tablets should be taken with at least 6 to 8 ounces (oz) of water. The oral solution should be taken with at least 2 oz of water.

Mechanism of action

Fosamax is a bisphosphonate medication. It works by binding under osteoclasts, which then bind to bone surface. However, osteoclasts lack the border that causes resorption. In this way, Fosamax inhibits osteoclasts from working, so bone breakdown is blocked. Because Fosamax blocks osteoclasts, rate of bone formation occurs faster than bone breakdown. This increases bone mineral density as well.

Pharmacokinetics and metabolism

In females,* alendronate taken in the morning, 2 hours before breakfast, has a bioavailability of 0.64%. In males,* the bioavailability of alendronate taken in the morning, 2 hours before breakfast, is 0.59%. The oral tablet and solution have equal bioavailability.

Taking alendronate with coffee or orange juice decreases the bioavailability of the drug by about 60%. Therefore, alendronate should be taken 30 minutes before other food, drink, or medications.

The volume of distribution at steady state is at least 28 liters. Alendronate is about 78% plasma protein bound. The terminal half-life of Fosamax is greater than 10 years, which is due to alendronate releasing from the skeleton.

* Sex and gender exist on spectrums. Use of the terms “female” and “male” in this article refers to sex assigned at birth.

Contraindications

Fosamax is contraindicated in people:

  • with esophageal abnormalities that delay emptying, such as a stricture
  • who cannot stand or sit for at least 30 minutes
  • with hypocalcemia
  • with hypersensitivity to any ingredient in Fosamax

People at risk for aspiration should not take the oral solution of Fosamax. The oral solution is only available as the generic form of Fosamax, called alendronate.

Storage

Fosamax should be stored at a room temperature of 59°F to 86°F (15°C to 30°C). It should be kept in a tightly sealed container, away from light. It should not be stored in areas where it could get damp or wet, such as bathrooms.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.

Fosamax Images