Tamiflu is a brand-name prescription drug. It’s approved to:

  • prevent influenza (“the flu”) in adults and children ages 1 year and older
  • treat the flu in adults and children ages 2 weeks and older who have had flu symptoms for 48 hours or less

Tamiflu belongs to a class of drugs called antivirals. It’s an influenza neuraminidase inhibitor, which prevents the flu virus from multiplying (making more virus) inside your body.

Tamiflu comes in two forms, both of which are taken by mouth. These forms include capsules and a liquid suspension. The capsules are available in three strengths: 30 mg, 45 mg, and 75 mg. The oral suspension (powder that’s dissolved in water) is available in one strength: 6 mg/mL (milligrams of drug per milliliter of liquid).

Effectiveness

In clinical studies, Tamiflu was effective both to treat and prevent the flu. Some of the results from these studies are described below.

Effectiveness for treating influenza

Two clinical studies that included adults with the flu looked at the time it took for their flu symptoms to get better or go away completely. The people were given either Tamiflu or a placebo (treatment with no active drug). In people taking Tamiflu, it took 1.3 fewer days for their flu symptoms to improve compared to the length of time in people taking the placebo.

Tamiflu was also studied in children with the flu who were ages 1 to 12 years. The children were given either Tamiflu or a placebo. In children taking Tamiflu, it took 1.5 fewer days for their flu symptoms to improve compared to the length of time in children taking the placebo.

Effectiveness for preventing influenza

Tamiflu has also been studied for use in preventing the flu during flu season. Studies looked at the number of people who get the flu while taking Tamiflu, compared to the number of people who get the flu while taking a placebo.

The studies included healthy people who hadn’t received their yearly flu vaccine. Studies also included people ages 65 years and older who were living in nursing homes. Only some of these people had received their flu shot. In the studies, 1% of all people taking Tamiflu developed the flu. Of those who didn’t take Tamiflu, 4% to 12% developed the flu.

Tamiflu contains the drug oseltamivir phosphate. This drug is available in a generic form as well as brand-name form.

Tamiflu can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Tamiflu. These lists do not include all possible side effects.

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

More common side effects

The more common side effects of Tamiflu can include:

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

Serious side effects

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

Serious side effects and their symptoms can include the following:

  • Delirium or abnormal behavior. Symptoms can include:
    • acting strangely
    • feeling “out of body”
    • hallucinations (seeing or hearing things that aren’t real)
    • Severe allergic reactions, which are discussed in more detail below.

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 several of the side effects this drug may or may not cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Tamiflu. It’s not known for sure how many people taking Tamiflu have allergic reactions to the drug. 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 Tamiflu. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

Rash

You may develop a skin rash while you’re using Tamiflu if you’re allergic to the drug. Some people taking Tamiflu have had a severe, life-threatening reaction called Stevens-Johnson syndrome. With this condition, a serious rash develops that involves large areas of blisters on your skin.

If you have a skin rash while taking Tamiflu, stop taking the drug and call your doctor right away. They can recommend whether you need medical treatment and offer ways to improve the rash.

Hallucinations

Some people taking Tamiflu have had delirium or hallucinations (seeing or hearing things that aren’t real). Some people have also had abnormal behaviors, which led to physical injury or death.

These side effects, which were seen most commonly in children taking Tamiflu, began and resolved quickly. It’s not known for sure whether Tamiflu caused the side effects, or if they were actually symptoms of the flu.

If you or your child has hallucinations or abnormal behaviors while taking Tamiflu, call your doctor right away. They can advise if Tamiflu use should be continued and whether any medical attention is needed.

Diarrhea

You may have diarrhea while you’re taking Tamiflu. In clinical studies, diarrhea occurred in about 7% of children who were taking the drug. Diarrhea wasn’t a common side effect in adults.

If you or your child has diarrhea while taking Tamiflu, it’s important to stay hydrated and receive electrolytes during treatment. Electrolytes can be found in pediatric supplement drinks. Some examples of these drinks, which can be found at your local drug store, include:

  • CeraLyte
  • Enfalyte
  • Pedialyte
  • Rehydralyte

It’s important to talk with your doctor or pharmacist about which electrolyte drink is best for you or your child. Some of these drinks contain a lot of sugar, which can worsen diarrhea instead of making it better.

Diarrhea may lead to dehydration (low fluid level), which may be serious if not treated. You should call your doctor right away if you or your child has the following symptoms, which may indicate dehydration:

  • a dry mouth
  • no tear production
  • no urination for 12 hours or urine that appears dark in color

Headache

You may have headaches while you’re taking Tamiflu. But headaches are also a common symptom of the flu.

In clinical studies, 2% of people with the flu who took Tamiflu had a headache. Of those with the flu who took a placebo (treatment with no active drug), 1% had a headache. In another study that looked at using Tamiflu to prevent the flu, 17% of people taking Tamiflu had headaches. Of those who took placebo, 16% had headaches.

If you’re bothered by headaches while you’re using Tamiflu, talk with your doctor. They may recommend ways to treat your headache and improve your discomfort.

Vomiting

You may vomit (throw up) while you’re taking Tamiflu. But vomiting is also a common symptom of the flu.

In clinical studies, 8% of people with the flu who took Tamiflu had vomiting. Of those with the flu who took a placebo (treatment with no active drug), 3% had vomiting. In another study that looked at using Tamiflu to prevent the flu, 2% of people who took Tamiflu had vomiting. Of those who took a placebo, 1% had vomiting.

If you have vomiting while you’re taking Tamiflu, it’s important to stay hydrated. Receiving electrolytes during your treatment can help you do this. Electrolytes can be found in sports drinks or pediatric supplement drinks, which you can purchase at your local drug store.

Vomiting may lead to dehydration (low fluid level), which may be serious if not treated. You should call your doctor right away if you have any of the following symptoms, which may indicate dehydration:

  • a dry mouth
  • no tear production
  • no urination for 12 hours or urine that appears dark in color

Side effects in children

During studies, vomiting was one of the most common side effects seen in children ages 2 weeks to 1 year. In this age group, 9% of children taking Tamiflu had vomiting. In children ages 1 year to 12 years, 16% of children had vomiting while taking Tamiflu. In the same age group, vomiting occurred in 8% of children taking a placebo (treatment with no active drug).

If your child is vomiting while they’re taking Tamiflu, it’s important to make sure they stay hydrated and receive electrolytes during treatment.

Vomiting may lead to dehydration (low fluid level), which may be serious if not treated. You should call your doctor right away if your child has any of the following symptoms, which may indicate dehydration:

  • a dry mouth
  • no tear production
  • no urination for 12 hours or urine that appears dark in color

Other common side effects seen in children taking Tamiflu can include diarrhea and diaper rash.

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

  • whether you’re using Tamiflu to either treat or prevent influenza (“the flu”)
  • your age
  • the form of Tamiflu you take
  • other medical conditions you may have

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 suit your needs.

Drug forms and strengths

Tamiflu comes in these two forms, which are both taken by mouth:

  • Capsules. These are available in three strengths: 30 mg, 45 mg, and 75 mg.
  • Oral suspension. This form of Tamiflu is a powder that’s been dissolved in water. The oral suspension is available in one strength: 6 mg/mL (milligrams of drug per milliliter of liquid).

Dosage for treatment of influenza

The typical dosage for flu treatment in adults and children ages 13 years or older is 75 mg taken by mouth twice daily for 5 days.

Tamiflu should be started within 2 days of when your flu symptoms began.

Dosage for prevention of influenza

The typical dosage for flu prevention in adults and children ages 13 years and older is 75 mg of Tamiflu taken by mouth once daily.

Your doctor may prescribe Tamiflu if you’ve had close contact with a person who has the flu. Tamiflu is most effective at preventing the flu when the drug is given within 2 days of having this contact. For flu prevention, you’ll take Tamiflu for at least 10 days.

Your doctor may also prescribe Tamiflu if there’s an influenza outbreak in your community. An outbreak is defined by an usually high number of people having the flu around the same period of time. If this happens, you’ll take Tamiflu for up to 6 weeks for prevention.

Pediatric dosage

The typical dosage of Tamiflu for children less than 13 years of age is described below for both treatment and prevention of the flu.

Dosage for flu treatment

For children ages 1 to 12 years, their dosage of Tamiflu will be based on their weight. Typical dosages for flu treatment, which are taken for 5 days, are as follows:

  • for children weighing 15 kilograms (about 33 pounds) or less: 30 mg taken by mouth twice daily
  • for children weighing more than 15 kilograms (about 33 pounds) to 23 kilograms (about 51 pounds): 45 mg taken by mouth twice daily
  • for children weighing more than 23 kilograms (about 51 pounds) to 40 kilograms (about 88 pounds): 60 mg taken by mouth twice daily
  • for children weighing more than 40 kilograms (about 88 pounds): 75 mg taken by mouth twice daily

For children ages 2 weeks to less than 1 year, the typical dose is 3 mg of Tamiflu per kilogram of their body weight. This dose is taken by mouth twice daily for 5 days.

Tamiflu should be started within 2 days of when your child’s flu symptoms began.

Dosage for flu prevention

For children ages 1 to 12 years, their dosage of Tamiflu will be based on their weight. Typical dosages for flu prevention, which are taken for 10 days, are as follows:

  • for children weighing 15 kilograms (about 33 pounds) or less: 30 mg taken by mouth once daily
  • for children weighing more than 15 kilograms (about 33 pounds) to 23 kilograms (about 51 pounds): 45 mg taken by mouth once daily
  • for children weighing more than 23 kilograms (about 51 pounds) to 40 kilograms (about 88 pounds): 60 mg taken by mouth once daily
  • for children weighing more than 40 kilograms (about 88 pounds): 75 mg taken by mouth once daily

Tamiflu should not be given to children less than 1 year of age to prevent influenza.

What if I miss a dose?

If you miss a dose of Tamiflu, take it as soon as you remember, unless it’s within 2 hours of your next dose. If it’s within 2 hours, just skip the missed dose and take your next dose as scheduled.

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.

Will I need to use this drug long term?

Tamiflu is meant to be used short term for both treating and preventing the flu.

Most people will take Tamiflu for 5 days when it’s used to treat the flu. When it’s used to prevent the flu, Tamiflu is typically taken for 10 days. But it can be used for up to 6 weeks for flu prevention if there’s a community outbreak.

Tamiflu isn’t meant to be used long term. Your doctor will recommend how long you should take this drug.

Tamiflu isn’t currently available to purchase over the counter (OTC). However, one drug manufacturer is currently working with the Food and Drug Administration (FDA) to make Tamiflu available OTC.

The FDA has specific requirements that must be met before a drug can be sold OTC. This includes testing to make sure the drug can be purchased and used safely without a prescription. While the drug manufacturer works on meeting those requirements, Tamiflu is only available by prescription. It could be several years before Tamiflu is available to purchase over the counter.

The Food and Drug Administration (FDA) approves prescription drugs such as Tamiflu to treat certain conditions. Tamiflu 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.

Tamiflu for influenza

Tamiflu is used both to treat and prevent influenza, which is also called the flu. More information about the influenza virus and these uses is described below.

What is influenza?

Influenza is a condition caused by the influenza virus, which infects your nose, throat, and lungs. This virus is spread easily though coughing, sneezing, or talking. After you’ve been infected with the virus, it usually takes about 1 to 4 days for you to develop flu symptoms.

Symptoms of the flu can include:

  • fever
  • headache
  • muscle aches
  • joint pain
  • cough
  • chills
  • sore throat
  • stuffy nose
  • nausea
  • vomiting
  • diarrhea

There are three types of the influenza virus, called type A, type B, and type C. If you’re infected with a certain type of the virus, you’ll have that type of infection. For example, if you’ve been infected with type A influenza virus, you’ll have type A flu (also called influenza A).

Tamiflu is effective to treat certain strains of influenza A and influenza B. Some strains of the virus are resistant to (do not improve with) Tamiflu. That means that if you’re infected with of these strains, your symptoms may not improve with Tamiflu treatment.

Tamiflu for treatment of influenza

Tamiflu is approved to treat the flu in adults and children ages 2 weeks and older. For this use, the drug is given to people who’ve had flu symptoms for up to 48 hours.

Effectiveness for treating influenza

Two clinical studies that included adults with the flu looked at the time it took for their flu symptoms to get better or go away completely. The people were given either Tamiflu or a placebo (treatment with no active drug). In people taking Tamiflu, it took 1.3 fewer days for their flu symptoms to improve compared to the length of time in people taking the placebo.

Tamiflu was also studied in children with the flu who were ages 1 to 12 years. The children were given either Tamiflu or a placebo. In children taking Tamiflu, it took 1.5 fewer days for their flu symptoms to improve compared to the length of time in children taking the placebo.

Tamiflu for prevention of influenza

Tamiflu is also approved to help prevent the flu in adults and children ages 1 year and older. If you’re exposed to people who have the flu or you’re at high risk of getting it, your doctor may prescribe Tamiflu to help keep you from getting the flu.

Effectiveness for preventing influenza

Tamiflu has also been studied for use in preventing the flu during flu season. Studies have looked at the number of people who get influenza while taking Tamiflu, compared to the number of people who get influenza while taking a placebo (treatment with no active drug).

The studies included healthy people who hadn’t received their yearly flu vaccine. Studies also included people ages 65 years and older who were living in nursing homes. Only some of these people had received their flu shot. In the studies, 1% of all people taking Tamiflu developed the flu. Of those who didn’t take Tamiflu, 4% to 12% developed the flu.

Tamiflu for other conditions

In addition to the uses listed above, you may wonder if Tamiflu is used for certain other conditions. Here we describe conditions that Tamiflu isn’t approved to treat.

Tamiflu for parainfluenza (not an appropriate use)

Tamiflu isn’t approved to treat parainfluenza viruses, and it shouldn’t be given for this use. Human parainfluenza viruses (HPIVs) cause symptoms similar to those caused by influenza virus. However, HPIVs belong to a different class of viruses than influenza virus does. For this reason, Tamiflu won’t be effective for treating HPIVs.

If you have flu-like symptoms, you should make an appointment to see your doctor. They can recommend the best treatment option for your condition.

Tamiflu for colds (not an appropriate use)

Tamiflu isn’t approved to treat the common cold, and it shouldn’t be used for this condition. The common cold can be caused by many different viruses that infect your lungs and nasal passages. The most common virus that causes the cold is called rhinovirus. However, Tamiflu doesn’t work to treat rhinovirus.

While the common cold and influenza cause similar symptoms, flu symptoms are generally worse than cold symptoms. If you have cold or flu symptoms, make an appointment to see your doctor. They can recommend the best treatment option for your condition.

Tamiflu and children

Tamiflu can be used to treat the flu in children ages 2 weeks and older. It can also be used to prevent the flu in children ages 1 year and older. For more details on these uses, see the sections “Tamiflu for treatment of influenza” and “Tamiflu for prevention of influenza” above.

Effectiveness in children

One clinical study looked at using Tamiflu to treat the flu in children ages 1 to 12 years. The children were given either Tamiflu or a placebo (treatment with no active drug). In children who received Tamiflu, it took 1.5 fewer days for them to feel better compared to the length of time it took children who received a placebo.

Tamiflu works to treat influenza by shortening the duration and lowering the severity of flu symptoms. However, flu symptoms can still be uncomfortable and interfere with your daily activities. Tamiflu can be taken in combination with other drugs that are used to reduce symptoms of the flu. Examples of over-the-counter (OTC) drugs that may be used with Tamiflu are listed below.

Examples of drugs that reduce body aches, pain, and fever include:

Examples of drugs that improve congestion (stuffy nose) include:

  • pseudoephedrine (Sudafed D)
  • phenylephrine (Sudafed PE)
  • oxymetazoline nasal spray (Afrin)

Examples of drugs that reduce chest congestion and coughing include:

  • guaifenesin (Mucinex)
  • dextromethorphan (Delsym or Robitussin)

Other OTC medications such as Theraflu, which contains different combinations of these drugs, may also help to improve flu symptoms. Talk with your doctor or pharmacist about whether or not you should take any of these medications.

Some of the drugs listed above can’t be used in children. Be sure to talk with your doctor or pharmacist before you or your child starts taking a new medication. This is important to do, even if the medication is sold over the counter.

Other drugs are available that can treat or prevent influenza (“the flu”). Some may be better suited for you than others. If you’re interested in finding an alternative to Tamiflu, 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 treatment of influenza

Examples of other drugs that may be used to treat the flu include:

  • zanamivir (Relenza)
  • baloxavir marboxil (Xofluza)
  • peramivir (Rapivab)

Alternatives for prevention of influenza

Examples of other drugs that may be used to prevent the flu include:

  • zanamivir (Relenza)
  • influenza vaccination (flu shot)

Influenza vaccination

The flu vaccine is the most effective way to prevent infections from the flu. The Centers for Disease Control and Prevention (CDC) recommends that every person ages 6 months and older who is healthy enough to get a flu vaccine get one. Getting vaccinated helps to prevent influenza infections and spreading the virus between people.

Most flu vaccines are given by injection (called a flu shot). However, the FluMist vaccine is given as a nasal spray. The CDC recommends that you receive a flu vaccine each year. Talk with your doctor for more information about the different types of vaccines, and to schedule a time to get your flu vaccine.

You may wonder how Tamiflu compares to other medications that are taken for influenza (“the flu”). Here we look at how Tamiflu and Oscillococcinum are alike and different.

About

Tamiflu contains oseltamivir, which is an antiviral drug that works to treat the flu. Tamiflu is a prescription drug that’s been approved by the Food and Drug Administration (FDA) both to treat and prevent the flu.

Oscillococcinum contains a homeopathic blend of ingredients, which are sometimes used to relieve flu symptoms. The safety and effectiveness of this medication to treat the flu hasn’t been evaluated by the FDA.

Uses

Tamiflu is approved to treat influenza in adults and children ages 2 weeks and older. For this use, it’s given to people who’ve had flu symptoms for up to 48 hours. Tamiflu is also approved to prevent the flu in adults and children ages 1 year and older.

Oscillococcinum is a homeopathic remedy that’s sometimes used to relieve flu symptoms. It’s meant to be used by adults and children ages 2 years and older.

Drug forms and administration

Tamiflu is taken by mouth, either once or twice daily. It comes in these two forms:

  • Capsules. These are available in three strengths: 30 mg, 45 mg, and 75 mg.
  • Oral suspension. This form of Tamiflu is a powder that’s been dissolved in water. The oral suspension is available in one strength: 6 mg/mL (milligrams of drug per milliliter of liquid).

Oscillococcinum is also taken by mouth. It comes as granules that dissolve when they’re placed under your tongue. The granules come in small plastic tubes that hold 0.04 ounces of the medication.

Side effects and risks

Tamiflu is an FDA-approved drug. This means that side effects of the drug have been reported in clinical studies. It also means that Tamiflu has been proven safe and effective to use for certain conditions.

Oscillococcinum hasn’t been well studied in clinical trials. Side effects of this medication haven’t been reported and aren’t known for sure.

Because of this, it’s not possible to compare the side effects of Tamiflu and Oscillococcinum.

Effectiveness

Tamiflu is a prescription drug that’s used both to treat and prevent influenza. It has been found effective for these uses in clinical studies.

Oscillococcinum, on the other hand, is a homeopathic preparation that’s used to treat flu symptoms. However, it hasn’t been evaluated by the FDA for effectiveness and safety.

These drugs haven’t been directly compared in clinical studies.

Costs

Tamiflu is the brand-name form of oseltamivir. This drug is also available as a generic medication. You’ll need a prescription to use either form of the drug. To find out cost information for Tamiflu, visit GoodRx.com. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Oscillococcinum is an OTC medication that doesn’t require a prescription. Prices will vary depending on where you purchase this medication.

You may wonder how Tamiflu compares to other medications that are prescribed for similar uses. Here we look at how Tamiflu and Xofluza are alike and different.

About

Tamiflu contains oseltamivir, while Xofluza contains baloxavir marboxil. These drugs are both antivirals that work in your body to treat influenza (“the flu”).

Uses

Tamiflu is approved to treat the flu in adults and children ages 2 weeks and older. For this use, it’s given to people who’ve had flu symptoms for up to 48 hours. Tamiflu is also approved to prevent the flu in adults and children ages 1 year and older.

Xofluza is approved to treat the flu in adults and children ages 12 years and older who’ve had flu symptoms for 48 hours or less.

Drug forms and administration

Tamiflu is taken by mouth, either once or twice daily. It comes in these two forms:

  • Capsules. These are available in three strengths: 30 mg, 45 mg, and 75 mg.
  • Oral suspension. This form of Tamiflu is a powder that’s been dissolved in water. The oral suspension is available in one strength: 6 mg/mL (milligrams of drug per milliliter of liquid).

Xofluza is also taken by mouth. It comes as tablets that are taken as a single, one-time dose. It’s available in two strengths: 20 mg and 40 mg.

Side effects and risks

Tamiflu and Xofluza both contain antiviral drugs. Therefore, both medications can cause very similar side effects. Below are examples of these side effects.

More common side effects

These lists contain examples of more common side effects that can occur with Tamiflu, with Xofluza, or with both drugs (when taken individually). The common side effects seen with each drug can also be symptoms of the flu.

  • Can occur with Tamiflu:
    • vomiting
    • general body pain
  • Can occur with Xofluza:
    • bronchitis (swelling in your airways and lungs)
    • nasopharyngitis (swelling in your nasal passages or throat)
  • Can occur with both Tamiflu and Xofluza:
    • nausea
    • headache

Serious side effects

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

  • Can occur with Tamiflu:
    • delirium or abnormal behavior
    • severe allergic reaction, including anaphylaxis or a serious, life-threatening rash
  • Can occur with Xofluza:
    • no unique serious side effects
  • Can occur with both Tamiflu and Xofluza:
    • no shared serious side effects

Effectiveness

Tamiflu and Xofluza are both approved to treat influenza. Tamiflu is also approved to prevent it.

A study that included adults with influenza directly compared Tamiflu and Xofluza. The study looked at the time it took for flu symptoms to improve or go away completely. The people were given either Tamiflu, Xofluza, or a placebo (treatment with no active drug).

In the study, it took 53.8 hours for people’s flu symptoms to improve when they were given Tamiflu. When they were given Xofluza, it took 53.5 hours for people’s flu symptoms to improve. Both Tamiflu and Xofluza improved people’s flu symptoms about 26 hours sooner than the placebo did.

Costs

Tamiflu is the brand-name form of oseltamivir. This drug is also available as a generic medication. Xofluza is only available as a brand-name drug. There are currently no generic forms of Xofluza available. Brand-name medications usually cost more than generics.

According to estimates on GoodRx.com, brand-name Tamiflu and Xofluza generally cost about the same. The actual price you’ll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

It’s not known for sure if Tamiflu is safe to take during pregnancy. There haven’t been any clinical studies that compared the use of Tamiflu versus a placebo (treatment with no active drug) in pregnant women.

However, some studies have looked at pregnant women who took Tamiflu during any trimester of their pregnancy. These studies didn’t show an increased risk of birth defects when Tamiflu was used.

In animal studies, Tamiflu also didn’t cause any negative effects to fetuses exposed to the drug. But keep in mind that animal studies don’t always predict what will happen in humans.

The Centers for Disease Control and Prevention (CDC) recommends Tamiflu as the preferred option for treating influenza in pregnant women.

If you’re pregnant and you get the flu, talk with your doctor about treatment options. Also, talk with your doctor about getting your flu vaccine during pregnancy to help prevent influenza infections.

It’s not known if Tamiflu is safe to take during pregnancy. If you or your sexual partner can become pregnant, talk with your doctor about your birth control needs while you’re using Tamiflu.

Tamiflu has been found in breast milk when it’s taken by lactating women. However, it’s not known if it’s safe for children less than 12 weeks of age to consume the drug in breast milk.

If you’re breastfeeding and considering treatment with Tamiflu, talk with your doctor. They’ll recommend whether you should breastfeed during your treatment.

Here are answers to some frequently asked questions about Tamiflu.

Is Tamiflu safe for older people to take?

Yes, it’s safe. In clinical studies, Tamiflu was given to 1,994 people who were ages 65 years and older, including 1,048 people ages 75 years and older. There were no differences in the safety or effectiveness of Tamiflu in these age groups compared to the safety or effectiveness seen in younger people taking the drug.

If you’re over the age of 65 years, and you’re interested in taking Tamiflu, talk with your doctor to see if it’s an option for you.

Is Tamiflu an antiviral?

Yes, it is. Tamiflu contains the active drug oseltamivir, which belongs to a class of antiviral drugs called influenza neuraminidase inhibitors. These drugs target the influenza virus and prevent it from multiplying (making more virus) inside of your body. This helps your immune system to fight off the virus.

Tamiflu is effective to treat certain strains of influenza A and influenza B virus.

Will I still be contagious if I’m taking Tamiflu for the flu?

Yes, you may be contagious (able to pass the infection to other people). Influenza virus is highly contagious. It can spread easily through droplets of saliva, or when someone coughs or sneezes.

If you’re taking Tamiflu, the drug will help fight the influenza virus inside of you. But you may still be able to infect other people while you’re taking the drug.

People who have the flu are contagious for up to 5 to 7 days after their flu symptoms begin. Even if you’re feeling better, you may still be able to spread the flu during this time.

You can help lower the risk of spreading influenza by:

  • washing your hands often
  • covering your face when you cough or sneeze
  • avoiding touching your face, especially your eyes, nose, and mouth
  • staying home when you’re sick

Does Tamiflu treat bacterial infections?

No, Tamiflu doesn’t work to treat infections caused by bacteria. Tamiflu contains the active drug oseltamivir, which belongs to a class of antiviral drugs called influenza neuraminidase inhibitors. These drugs target the influenza virus and prevent it from multiplying (making more virus) inside your body. This helps your immune system to fight off the infection.

Some bacterial infections can cause the same symptoms as the influenza virus does. But Tamiflu isn’t effective to treat bacterial infections.

If you think you have a bacterial infection, talk with your doctor about your treatment options. Your doctor may prescribe antibiotics that are effective to treat your infection.

Can I get a flu vaccine while taking Tamiflu?

Yes, you possibly can. There are two types of flu vaccines: inactivate (does not contain live virus) and live (contains live virus).

You can get an inactivate flu vaccine when you’re using Tamiflu. However, you can’t get the live influenza vaccine (which comes as a nasal spray) while you’re taking Tamiflu. This is because the live vaccine may not work as well for you since Tamiflu will be fighting off the virus you’re given in the vaccine.

Talk with your doctor or pharmacist about when the right time is for you to get a flu shot. If you have the flu or you’re currently taking Tamiflu, remind your doctor or pharmacist. They’ll be able to recommend whether you should get a flu vaccine.

You should take Tamiflu according to your doctor or healthcare provider’s instructions.

When to take

When it’s used to treat influenza, Tamiflu should be taken by mouth twice daily. It’s best to take your doses about every 12 hours. This keeps the Tamiflu level constant in your body so that the drug can work properly to treat the flu.

When it’s used to prevent influenza, Tamiflu is taken by mouth once each day. It’s best to take your doses about every 24 hours. This keeps the Tamiflu level constant in your body so that the drug can work properly to prevent the flu.

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.

Taking Tamiflu with food

Tamiflu can be taken on an empty stomach or with food. If you have nausea or vomiting while using the drug, taking Tamiflu with food may help reduce these side effects.

Can Tamiflu capsules be crushed, split, or chewed?

Tamiflu capsules shouldn’t be crushed or chewed. But in some cases, the capsules can be split open.

If you have trouble taking Tamiflu, your doctor or pharmacist may show you how to open the capsules. Then you’ll mix the contents of the capsule with a sweet liquid (such as chocolate syrup) and swallow it.

Your doctor or pharmacist may also prescribe the oral suspension (liquid) form of Tamiflu for you. This form may be easier for you to take.

It’s possible to overdose on Tamiflu by taking more than your recommended dosage of the drug. Overdose may lead to serious side effects.

Overdose symptoms

Symptoms of an overdose can include:

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 go to the nearest emergency room right away.

It’s not known if Tamiflu is safe to use with alcohol. In general, you shouldn’t drink alcohol when you have influenza, because doing so can worsen flu symptoms, such as nausea or headache.

If you have influenza, or you’re taking Tamiflu, talk with your doctor before drinking alcohol.

Tamiflu isn’t known to interact with other medications. However, it may 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.

Before taking Tamiflu, 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. Also, talk with them about whether you should receive your flu vaccine while you’re taking Tamiflu.

Tamiflu and flu vaccines

There are two types of flu vaccines: inactivate (does not contain live virus) and live (contains live virus).

If you receive the live influenza vaccine while you’re taking Tamiflu, it may be less effective to protect you from the flu. This is because the antiviral drug contained in Tamiflu will attack and kill the live virus given to you in the vaccine.

However, you may be able to receive the inactive flu vaccine, which does not contain live virus, while you’re taking Tamiflu.

If you have the flu, or you’re taking Tamiflu, talk with your doctor about your options for receiving a flu vaccination.

As with all medications, the cost of Tamiflu can vary. To find current prices for Tamiflu in your area, check out GoodRx.com:

The cost you find on GoodRx.com is what you may pay without insurance. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.

Your insurance plan may require you to get prior authorization before approving coverage for Tamiflu. This means that your doctor will need to send a request to your insurance company asking them to cover the drug. The insurance company will review the request and let you and your doctor know if your plan will cover Tamiflu.

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

Financial and insurance assistance

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

Genentech, the manufacturer of Tamiflu, may offer assistance to help lower the cost of Tamiflu. For more information and to find out if you’re eligible for support, call 877-436-3683 or visit the program website.

Tamiflu is approved both to treat and prevent influenza. Tamiflu contains the active drug oseltamivir. This drug is an antiviral that belongs to a class of drugs called influenza neuraminidase inhibitors.

Once inside your body, Tamiflu gets converted into its active form (oseltamivir carboxylate). This active form of the drug attaches to the influenza virus and prevents it from multiplying (making more virus) inside your body. This allows your immune system to fight off the virus.

The drug also prevents the virus from releasing viral particles, which spread the infection inside your body and to other people.

Tamiflu is effective to treat and prevent certain strains of influenza A and influenza B virus.

How long does it take to work?

It’s difficult to say how long it takes for Tamiflu to work, because the drug works differently in different people. How quickly Tamiflu will work for you depends on whether you’re using the drug to treat or prevent influenza. It also depends on other factors, such as your age and overall health.

If you have flu symptoms, the sooner you begin taking Tamiflu, the quicker you’ll start feeling better.

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

  • Fructose intolerance. If you have hereditary fructose intolerance, you may not be able to take the oral suspension form of Tamiflu. This form of Tamiflu contains 2 g of sorbitol for every 75 mg of Tamiflu. This amount of sorbitol is over the maximum daily limit for people with hereditary fructose intolerance. Consuming this amount of fructose may cause stomach upset and diarrhea. If you have fructose intolerance, talk with your doctor before starting Tamiflu.
  • Bacterial infection. If you have a bacterial infection, taking Tamiflu will not treat the infection. Certain bacterial infections can cause the same symptoms as the influenza virus causes. It’s important that your doctor makes sure whether your infection is caused by influenza or caused by bacteria before prescribing Tamiflu to you.
  • Pregnancy. It’s not known if Tamiflu is safe for use in pregnancy. For more information, please see the “Tamiflu and pregnancy” section above.
  • Breastfeeding. Tamiflu does pass into breast milk when it’s taken by lactating women. However, it’s not known whether it’s safe for children less than 12 weeks of age to consume this milk. For more information, please see the “Tamiflu and breastfeeding” section above.

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

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

The expiration date helps guarantee the effectiveness of the medication 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 to 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.

Tamiflu capsules should be stored at room temperature (about 77°F/25°C), in a tightly sealed container away from light. Avoid storing this medication in areas where it could get damp or wet, such as in bathrooms.

The Tamiflu oral suspension (liquid) can be stored in the refrigerator, at a temperature of 36°F to 46°F (2°C to 8°C). If refrigerated, it can be stored for up to 17 days. The oral suspension can also be stored at room temperature (about 77°F/25°C). If left at room temperature, it can be stored for up to 10 days. Tamiflu oral suspension should not be frozen.

Disposal

If you no longer need to take Tamiflu 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.

The FDA website 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

Tamiflu is indicated for the treatment of acute and uncomplicated illness caused by influenza A and B. For this indication, Tamiflu can be given to adults and children ages 2 weeks and older who have had symptoms for up to 48 hours.

Tamiflu is also indicated for the prophylaxis of influenza A and B in adults and children ages 1 year and older.

Mechanism of action

Tamiflu contains oseltamivir, which is an influenza neuroaminidase inhibitor. It works by inhibiting the release of viral particles. Tamiflu is effective against influenza A (H1N1, H3N2) and influenza B.

Pharmacokinetics and metabolism

Oseltamivir is a prodrug that is absorbed from the gastrointestinal tract and converted via hepatic esterases into the active form oseltamivir carboxylate. The half-life of oseltamivir carboxylate is 1 to 3 hours. This active metabolite is eliminated unchanged in urine.

Contraindications

Tamiflu is contraindicated in patients with a known serious hypersensitivity to oseltamivir or to any of the components of Tamiflu.

Storage

Tamiflu capsules should be stored at room temperature (about 77°F/25°C) in a tightly sealed container away from light and moisture.

Tamiflu suspension that has not been reconstituted should be stored at room temperature (77°F/25°C) in a tightly sealed container away from light until the expiration date.

Tamiflu suspension that has been reconstituted can be stored in the refrigerator at a temperature of 36°F to 46°F (2°C to 8°C) for up to 17 days. The suspension should not be frozen. Tamiflu suspension can also be stored at room temperature (about 77°F/25°C) for up to 10 days.

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 other 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.