Fosamax (alendronate sodium) is a brand-name prescription drug prescribed for the following uses in adults:

As with other medications, Fosamax can interact with alcohol and certain other drugs. It can also interact with some supplements and foods. An interaction occurs when one substance causes another substance to have a different effect than expected.

For details about Fosamax’s interactions, keep reading. For additional information about Fosamax, including details about its uses, see this article.

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

In some cases, certain factors or conditions could prevent your doctor from prescribing Fosamax due to the risk of harm. These are known as contraindications. The contraindications of Fosamax include:

Having problems with your esophagus

If you have a problem with your esophagus that causes trouble swallowing, your doctor will typically not prescribe Fosamax. Examples of these problems include narrowing in your esophagus or a problem with the nerves in your esophagus.

With these problems, Fosamax can stay in your esophagus for too long after taking a dose. This can irritate the lining of your esophagus or cause ulcers (sores). To find out about other treatment options, talk with your doctor.

Having trouble sitting upright or standing

If you’re unable to sit upright or stand for at least 30 minutes, your doctor will typically not prescribe Fosamax. Remaining upright after taking Fosamax helps the tablet travel into your stomach.

If you’re unable to remain upright for 30 minutes after taking Fosamax, it can stay in your esophagus too long. This can cause irritation or ulcers in your esophagus. To find out about other treatment options, talk with your doctor.

Having hypocalcemia (low calcium level)

Fosamax can lower the level of calcium in your blood. If you already have a low calcium level, your doctor will typically not prescribe Fosamax. Instead, they’ll likely prescribe a calcium supplement to increase your calcium level before you can start Fosamax.

Having had an allergic reaction to Fosamax or any of its ingredients

If you have had an allergic reaction to Fosamax or any of its ingredients, your doctor will likely not prescribe Fosamax. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.

Note: Before you start treatment with Fosamax, it’s important to tell your doctor if any of these contraindications apply to you. They can determine whether to prescribe Fosamax.

Fosamax hasn’t been reported to interact with alcohol. However, there are a few things to consider if you want to drink alcohol while taking this medication.

  • You should not drink alcohol for at least 30 minutes after taking Fosamax. Drinking anything other than plain water during this time can stop Fosamax from being absorbed into your body correctly. This can make it less effective than usual.
  • Drinking alcohol while you’re taking Fosamax may raise your risk of certain Fosamax side effects. These include digestive side effects, such as nausea, indigestion, and diarrhea. Drinking excessively may also raise your risk of irritation or ulcers (sores) in your esophagus, which is a serious side effect of Fosamax.
  • Long-term heavy drinking may raise your risk of developing osteoporosis. And if you already have osteoporosis, it could make your condition worse. Keep in mind that Fosamax is used to prevent and treat osteoporosis.

If you drink alcohol, talk with your doctor about how much is safe to consume while you’re taking Fosamax.

Before you start treatment with Fosamax, tell your doctor and pharmacist which prescription, over-the-counter, and other medications you take. By sharing this information with them, you may help prevent possible interactions. (To learn whether Fosamax interacts with supplements, herbs, or vitamins, see the “Fosamax and other interactions” section below.)

Note that you should not take any other oral medication, even those that don’t interact with Fosamax, for at least 30 minutes after taking a dose of Fosamax. Taking anything other than plain water during this time can stop Fosamax from being absorbed into your body correctly. This can make Fosamax less effective than usual.

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

Here’s a table of drugs that can interact with Fosamax. Keep in mind that this table doesn’t include all drugs that may interact with Fosamax. Some of these interactions are described in detail just below in “Drug interactions in depth.”

Drug class or drug nameDrug examplesInteraction result with Fosamax
antacids• calcium carbonate (Tums, Alka-Seltzer)
• calcium hydroxide/magnesium hydroxide (Rolaids)
• magnesium hydroxide (Milk of Magnesia)
• aluminum hydroxide/magnesium hydroxide/simethicone (Maalox, Mylanta)		can make Fosamax less effective than usual
nonsteroidal anti-inflammatory drugs (NSAIDs)• aspirin
• celecoxib (Celebrex)
• ibuprofen (Advil, Motrin)
• meloxicam (Mobic)
• naproxen (Naprosyn, Aleve)		can increase the risk of side effects of Fosamax and NSAIDs

Here’s a closer look at certain drug interactions of Fosamax.

Antacids

Antacids are medications used to treat indigestion and heartburn.

Interaction result. Taking antacids within 30 minutes after taking Fosamax can make Fosamax less effective.

Interaction explained. Taking antacidswithin 30 minutes after taking Fosamax can stop Fosamax from being absorbed into your body correctly.

Examples of antacid drugs. Here are some antacid drugs that may interact with Fosamax:

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

Steps you or your doctor may take. You should take your dose of Fosamax at least 30 minutes before taking any other medication. Do not take antacid medications until at least 30 minutes after taking your dose of Fosamax.

Nonsteroidal anti-inflammatory drugs (NSAIDs)

NSAIDs are pain-relieving medications that also reduce inflammation (swelling). Aspirin is an NSAID that’s also used as a blood thinner.

Interaction result. Taking an NSAID with Fosamax may raise your risk of digestive side effects such as nausea, indigestion, and abdominal pain. It may also raise your risk of inflammation, ulcers (sores), or bleeding in your esophagus or stomach.

Interaction explained. Both Fosamax and NSAIDs can irritate the linings of your esophagus and stomach. Taking these medications together can increase this irritation. This may raise your risk of digestive side effects. It may also lead to inflammation, ulcers (sores), or bleeding in your esophagus or stomach.

Examples of NSAIDs. Here are some NSAIDs that may interact with Fosamax:

Steps you or your doctor may take. If your doctor recommends taking an NSAID with Fosamax, they may monitor you more closely. Talk with your doctor if you have new or worsening digestive side effects while taking these medications together. Specifically, talk with your doctor if you have trouble swallowing, pain when swallowing, indigestion, heartburn, or pain behind your sternum (breastbone). These could be symptoms of inflammation or ulcers in your esophagus or stomach.

Fosamax may have other interactions, such as with supplements, foods, vaccines, or even lab tests. You’ll find details below. Keep in mind that the following information does not include all other possible interactions with Fosamax.

Fosamax interactions with supplements

Before you start treatment with Fosamax, tell your doctor and pharmacist which supplements, herbs, and vitamins you take. By sharing this information with them, you may help prevent possible interactions.

You should not take any supplements, especially those containing calcium or magnesium, for at least 30 minutes after taking a dose of Fosamax. Taking anything other than plain water during this time could stop Fosamax from being absorbed into your body correctly. This can make Fosamax less effective than usual.

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

Fosamax interactions with herbs

There are no specific reports of herbs interacting with Fosamax. However, that doesn’t mean herbal interactions won’t occur or be recognized in the future. Because of this, it’s important to check with your doctor or pharmacist before taking any of these products during Fosamax treatment.

Note that you should not take any herbs for at least 30 minutes after taking a dose of Fosamax. Taking anything other than plain water during this time could stop Fosamax from being absorbed into your body correctly. This can make Fosamax less effective than usual.

Fosamax interactions with vitamins

There are no specific reports of vitamins interacting with Fosamax. However, that doesn’t mean vitamin interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before taking any vitamin product with Fosamax.

Note that you should not take any vitamins for at least 30 minutes after taking a dose of Fosamax. Taking anything other than plain water during this time could stop Fosamax from being absorbed into your body correctly. This can make Fosamax less effective than usual.

Fosamax interactions with food

You should not eat or drink anything other than plain water before taking Fosamax and for at least 30 minutes after taking Fosamax. If you eat or drink anything other than plain water during this time, this could stop Fosamax from being absorbed into your body correctly. This can make Fosamax less effective than usual.

Fosamax and vaccines

There are no specific reports of vaccines interacting with Fosamax. However, that doesn’t mean vaccine interactions won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist before getting any vaccines while taking Fosamax.

Fosamax and lab tests

There are no specific reports of Fosamax affecting lab tests. However, that doesn’t mean interactions with lab tests won’t occur or be recognized in the future. Because of this, you should talk with your doctor or pharmacist if you need to have any lab tests while taking Fosamax.

FOSAMAX AND CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as cannabidiol (CBD), have not been specifically reported to interact with Fosamax. However, as with any drug or supplement, talk with your doctor before using cannabis in combination with Fosamax. The impact of cannabis may affect how well you stick to your Fosamax treatment plan.

Note: Cannabis is illegal at a federal level but is legal in many states to varying degrees.

Certain medical conditions and other factors may increase the risk of interactions with Fosamax. Before you take this drug, be sure to talk with your doctor about your health history. Fosamax may not be the right treatment option if you have certain medical conditions or other factors affecting your health.

Health conditions or factors that might interact with Fosamax include:

  • Problems with your esophagus. If you have a problem with your esophagus that causes trouble swallowing, your doctor will typically not prescribe Fosamax. To learn more, see “When to avoid Fosamax” above.
  • Trouble sitting upright or standing. If you’re unable to sit upright or stand for at least 30 minutes, your doctor will typically not prescribe Fosamax. For more information, refer to the “When to avoid Fosamax” section above.
  • Hypocalcemia (low calcium level). If you have a low calcium level, your doctor will typically not prescribe Fosamax. They’ll likely prescribe a calcium supplement to increase your calcium level before you can start Fosamax. If you don’t get enough calcium and vitamin D in your diet, your doctor may prescribe a calcium and vitamin D supplement to take with Fosamax. (Vitamin D helps your body absorb calcium.) Note that you should not take calcium and vitamin D supplements for at least 30 minutes after taking Fosamax.
  • Inflammation or ulcers in your digestive system. Fosamax can cause irritation or ulcers (sores) in your esophagus or stomach. If you already have inflammation or ulcers in your digestive system, Fosamax could worsen your condition. Talk with your doctor about whether Fosamax is right for you.
  • Risk of jaw and dental problems. Rarely, Fosamax may cause jawbone damage that could lead to dental problems. You may have a raised risk of this serious side effect if you have anemia (low red blood cell count), blood clotting problems, or cancer. Taking certain medications, such as corticosteroids, can also raise your risk of this serious side effect. Additionally, if you have oral health problems, poorly fitting dentures, or invasive dental procedures, this can also raise your risk. If any of these factors apply to you, ask your doctor whether Fosamax is right for you. If you need an invasive dental procedure while taking Fosamax, for example a tooth extraction or dental implant, be sure to talk with your doctor and dentist. They may recommend that you stop taking Fosamax for a time to lower your risk of jaw and dental problems.
  • Kidney problems. Fosamax is removed from your body by your kidneys. If you have kidney problems, Fosamax could build up in your body. This could raise your risk of side effects. If you have kidney problems, talk with your doctor about whether Fosamax is right for you. Depending on how well your kidneys are working, they may recommend other treatments that may be more suitable for you.
  • Pregnancy. It’s not known whether Fosamax is safe to take during pregnancy. However, due to a possible risk of fetal harm, your doctor will likely not prescribe Fosamax if you’re pregnant or planning to become pregnant. Talk with your doctor about other treatment options that may be better choices for you.
  • Breastfeeding. It’s not known whether Fosamax passes into breast milk. If you’re breastfeeding or planning to breastfeed, talk with your doctor about the possible risks and benefits of taking Fosamax.
  • Allergic reaction. If you’ve had an allergic reaction to Fosamax or any of its ingredients, your doctor will likely not prescribe Fosamax. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.

Here are some frequently asked questions about Fosamax and possible interactions.

Is there an interaction between Fosamax and Synthroid?

No, Fosamax isn’t known to interact with thyroid hormones such as levothyroxine (Synthroid). However, you should not take these medications at the same time of day. Doing so could stop Fosamax from being absorbed into your body correctly, which could make it less effective than usual.

You should always take your dose of Fosamax as soon as you get up in the morning. And you should not take any other medications, including Synthroid, for at least 30 minutes after taking Fosamax. Additionally, you should not eat or drink anything other than plain water for at least 30 minutes after taking Fosamax.

These instructions pose a slight problem for the timing of your Synthroid dose. It’s usually recommended that you take Synthroid about 30 minutes to 1 hour before breakfast. However, if you also take Fosamax, this means you’d have to take Fosamax when you get up and then wait at least 30 minutes before taking Synthroid. You’d then need to wait another 30 minutes to 1 hour before having breakfast. This schedule might not work for everyone. Instead, your doctor may recommend taking Fosamax in the morning and then waiting until bedtime to take Synthroid.

Note that if you take Synthroid at bedtime, you’ll need to have your evening meal at least 4 hours before taking Synthroid. Synthroid should be taken without food on an empty stomach.

If your doctor prescribes Fosamax and Synthroid, talk with them about the best way to take your doses to fit in with your daily schedule.

Is it safe to take Tylenol with Fosamax?

Yes, it’s generally considered safe to take acetaminophen (Tylenol) while you’re taking Fosamax. However, you should not take Tylenol until at least 30 minutes after taking Fosamax. Doing so could stop Fosamax from being absorbed into your body correctly, which could make it less effective than usual.

If you have questions about taking Tylenol with Fosamax, talk with your doctor.

You can take certain steps to help prevent interactions with Fosamax. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:

  • Let them know if you drink alcohol or use cannabis.
  • Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
  • Create a medication list, which your doctor and pharmacist can help you fill out.

It’s also important to read the Fosamax label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. And the paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions. (If Fosamax doesn’t come with paperwork, you can ask your pharmacist to print a copy.) If you need help reading or understanding this information, ask your doctor or pharmacist.

You can also help prevent interactions with Fosamax by taking it exactly as your doctor prescribes.

Besides learning about interactions, you may want to find out more about Fosamax. These resources might help:

  • Overview of Fosamax. For a general overview of Fosamax, you can see this article.
  • Dosage specifics. To learn about the dosage of Fosamax, see this article.
  • Facts about osteoporosis. To learn more about osteoporosis, see our list of osteoporosis articles.

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.