Rapivab (peramivir)

What is Rapivab?

Rapivab is a brand-name prescription medication. It’s FDA-approved to treat influenza (the flu) in people ages 2 years and older.

Rapivab should only be used in people with the flu who haven’t had symptoms for longer than 2 days. And, Rapivab shouldn’t be used to treat influenza that’s severe enough to require that you stay in the hospital.

Note: Rapivab was mainly studied in people with influenza type A, which is the most common type. Only a few people in the studies had influenza type B.

Drug details

Rapivab comes as a colorless liquid solution inside vials. Your healthcare provider will give Rapivab to you as an intravenous (IV) infusion. With an IV infusion, the drug is injected into a vein, typically in your arm, over a period of time.

Rapivab is available in one strength: 10 milligrams/milliliter (mg/mL). It contains the active drug peramivir, which is an antiviral drug that belongs to a class of medications known as neuraminidase inhibitors. (A class of drugs describes a group of medications that work in the same way.)

Effectiveness

For information about the effectiveness of Rapivab, see the “Rapivab uses” section below.

Rapivab generic

Rapivab contains the active drug peramivir. It’s available only as a brand-name medication. It’s not currently available in generic form. (A generic drug is an exact copy of the active drug in a brand-name medication.)

Rapivab cost

As with all medications, the cost of Rapivab can vary. The actual price you’ll pay depends on your insurance plan and where you receive the medication.

Before approving coverage for Rapivab, 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 unsure if you’ll need to get prior authorization for Rapivab, contact your insurance company.

Financial and insurance assistance

If you have questions about possible financial support to help lower the cost of Rapivab, talk with your doctor or hospital staff. They may know of cost assistance programs available at the hospital where you receive this drug.

You can also reach out to your insurance company. They can help you understand if Rapivab is covered under your plan. They may also be able to tell you if any financial assistance options are available for Rapivab.

Generic version

Rapivab is not available in a generic form. A generic drug is an exact copy of the active drug in a brand-name medication. Generics tend to cost less than brand-name drugs.

Rapivab side effects

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

For more information about the possible side effects of Rapivab, 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 they have approved. If you would like to notify the FDA about a side effect you’ve had with Rapivab, you can do so through MedWatch.

Mild side effects

Mild side effects of Rapivab can include*:

• diarrhea
• vomiting†

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 of Rapivab. To learn about other mild side effects, talk with your doctor or pharmacist or visit Rapivab’s prescribing information.
† Vomiting was reported only in children receiving Rapivab during clinical trials. There were no reports of vomiting in adults taking the drug during trials.

Serious side effects

Serious side effects from Rapivab 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 of Rapivab, which are further discussed in the “Side effect details” section below, include:

• allergic reaction
• behavioral changes, such as delirium or hallucinations

Side effects in children

In clinical studies of Rapivab, there were a few side effects reported in children that weren’t reported in adults. These side effects were:

• Proteinuria. With proteinuria, you have higher than normal levels of protein in your urine. In studies, proteinuria occurred in:
  • 3% of children taking Rapivab
  • 0% of children who took another antiviral drug called oseltamivir
• Fever. With a fever, your body temperature is higher than normal. In studies, fever occurred in:
  • 2% of children taking Rapivab
  • 0% of children who took oseltamivir
• Tympanic membrane erythema. With this condition, you have redness in your eardrum. In studies, tympanic membrane erythema occurred in:
  • 2% of children taking Rapivab
  • 0% of children who took oseltamivir
• Vomiting. In studies, vomiting occurred in:
  • 3% of children taking Rapivab
  • 9% of children who took oseltamivir

If you have questions about side effects that may affect children using Rapivab, talk with your doctor.

Side effect details

You may wonder how often side effects occur with this drug. Here’s some detail on certain side effects this drug may cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Rapivab. But it’s not known how many people had an allergic reaction to the drug during clinical trials.

Symptoms of a mild allergic reaction can include:

• skin rash
• itchiness
• flushing (warmth, swelling, or 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

In addition, severe skin reactions may happen as a result of an allergy to Rapivab. These reactions can include erythema multiforme and Stevens-Johnson Syndrome. Symptoms of these reactions can include:

• bulging skin lesions with red, purple, pink, or brown coloring
• skin blistering and peeling

Call your doctor right away if you have an allergic reaction to Rapivab as the reaction could become severe. But call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.

Behavioral changes

Although rare, Rapivab may cause changes in behavior. This wasn’t a side effect seen during clinical trials of the drug. But it has been reported since the drug was released onto the market. This means it’s not known if Rapivab is actually responsible for causing behavioral changes. It also isn’t known exactly how many people have had behavioral changes while taking Rapivab.

Examples of behavioral changes that were reported by people taking Rapivab after the drug was released onto the market include:

• delirium (change in mental function)
• hallucinations (seeing or hearing things that aren’t actually there)
• unusual behaviors

It’s important to note that influenza (the flu) itself, which Rapivab is used to treat, may be associated with these behavioral changes. So, it can be hard to know whether these symptoms are side effects of a drug or changes caused by the flu.

Most reports of behavioral changes with Rapivab were in children receiving the drug. These behavioral changes usually began and went away very quickly. Be sure to monitor yourself or others who are receiving Rapivab for signs of unusual behavior. Call your doctor if you notice any changes or have any concerns.

Diarrhea

You may have diarrhea as a side effect of Rapivab. In fact, this was the most common side effect during clinical trials of the drug. In the trials, diarrhea occurred in:

• 8% of people taking Rapivab
• 7% of people who received a placebo (treatment with no active drug)

None of the people who had diarrhea while taking Rapivab considered the side effect serious.

If you develop diarrhea that’s bothersome to you while you’re taking Rapivab, talk with your doctor. They’ll work with you to determine how to best manage this side effect. This may include recommending a medication for the diarrhea.

Rapivab dosage

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

• your age and weight
• other medical conditions you may have

The following information describes dosages that are commonly used or recommended. Your doctor will determine the best dosage to fit your needs.

Drug forms and strengths

Rapivab comes as a colorless liquid solution inside vials. Your healthcare provider will give Rapivab to you as an intravenous (IV) infusion. With an IV infusion, the drug is injected into a vein, typically in your arm, over a period of time.

Rapivab is available in one strength: 10 milligrams/milliliter (mg/mL).

Dosage for influenza

The recommended Rapivab dosage for treating influenza (the flu) is 600 mg given once as an IV infusion over 15 to 30 minutes. This dose is recommended in adults and children ages 13 years and older.

Your doctor may give you a different dosage of the drug depending on several factors. These include whether or not you have kidney disease. Be sure to talk with your doctor if you have any questions about the Rapivab dosage that’s right for you.

Children’s dosage

Rapivab is approved to treat influenza (the flu) in children ages 2 years and older. The recommended dosage of the drug in children varies depending on age. These recommended dosages are described below.

Rapivab dosage in children ages 2 through 12 years

The recommended Rapivab dosage for influenza in children ages 2 to 12 years is based on the child’s body weight. For this use, Rapivab is given at a dose of 12 milligrams per kilogram* (mg/kg) of body weight. And this dose is given as a one-time IV infusion that lasts about 15 to 30 minutes.

For example, at a dose of 12 mg/kg, a child weighing 44 pounds (lbs) or about 20 kg would receive one 240 mg dose of Rapivab.

Your doctor may give your child a different dosage depending on several factors, including whether your child has kidney disease. Be sure to talk with your doctor if you have any questions about the Rapivab dosage that’s right for your child.

* 1 kg is equal to about 2.2 lbs.

Rapivab dosage in children ages 13 years and older

The recommended Rapivab dosage for influenza in children ages 13 years and older is the same as for adults. For details, see the section above called “Dosage for influenza.”

Will I need to use this drug long term?

No, Rapivab isn’t meant to be given long-term. Instead, it’s only given short-term, as a single dose, in the hospital or clinic.

Alternatives to Rapivab

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

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

• baloxavir marboxil (Xofluza)
• oseltamivir (Tamiflu)
• zanamivir (Relenza)

Rapivab vs. Tamiflu

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

Ingredients

Rapivab contains the active drug peramivir, while Tamiflu contains the active drug oseltamivir. Both peramivir and oseltamivir are called antivirals.

Uses

Here’s a list of conditions that the Food and Drug Administration (FDA) has approved Rapivab and Tamiflu to treat.

• Both Rapivab and Tamiflu are FDA-approved to treat:
  • uncomplicated influenza (flu)* in people who haven’t had symptoms for longer than 2 days
• Tamiflu is also FDA-approved to:
  • prevent influenza infection in people ages 1 year and older

For treating the flu, Rapivab is approved for use in people ages 2 years and older. On the other hand, Tamiflu is approved to treat the flu in people ages 2 weeks and older.

* With uncomplicated influenza, the flu isn’t severe enough to require hospitalization.

Drug forms and administration

Rapivab is given by healthcare providers as an intravenous (IV) infusion. With an IV infusion, the drug is injected into a vein, typically in your arm, over a period of time.

Tamiflu comes as a capsule that’s taken by mouth. It’s also available as a powder that can be made into a liquid suspension that’s taken by mouth.

Side effects and risks

Rapivab and Tamiflu 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 each drug, as well as mild side effects that both drugs may share.

• Can occur with Rapivab:
  • diarrhea
• Can occur with Tamiflu:
  • headache
  • nausea
  • pain
• Can occur with both Rapivab and Tamiflu:
  • vomiting*

* For Rapivab, vomiting was reported only in children receiving the drug during clinical studies. There were no reports of vomiting in adults taking the drug. However, vomiting was reported in adults taking Tamiflu during clinical studies.

Serious side effects

Serious side effects that can occur with both Rapivab and Tamiflu (when taken individually) include:

• allergic reaction
• behavioral changes, such as delirium or hallucinations

Effectiveness

Rapivab and Tamiflu have different approved uses, but they’re both used to treat uncomplicated influenza infections.

These drugs haven’t been directly compared in clinical studies. But separate studies have found both Rapivab and Tamiflu to be effective in treating uncomplicated cases of influenza.

Costs

Rapivab costs much more than Tamiflu. The actual price you’ll pay for either drug depends on your insurance plan and where you receive the medication.

Rapivab is a brand-name drug. There are currently no generic forms of Rapivab. (A generic drug is an exact copy of the active drug in a brand-name medication. Brand-name medications usually cost more than generics.) Tamiflu is available as a generic medication called oseltamivir.

Rapivab uses

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

Rapivab for influenza

Rapivab is FDA-approved to treat influenza (the flu) in people ages 2 years and older. Specifically, the drug is approved for use in people who’ve had flu symptoms for no more than 2 days.

What influenza is

Influenza is an infection that’s caused by the influenza virus. There are three types of influenza viruses: type A, B, and C.

The type of virus that causes your flu infection determines the type of flu you have. For example, if you’ve gotten virus type B, you’ll have influenza type B.

Currently, Rapivab is approved for treating any type of influenza infection. However, Rapivab was mainly studied in people with influenza type A, which is the most common type. Only a few people in the studies had influenza type B.

Symptoms of the flu

The flu virus affects your respiratory system. It causes infection in your lungs, nose, and throat. Influenza is easily spread by coughing, sneezing, or talking. After getting the flu, people typically start to have symptoms within 1 to 4 days.

Symptoms of the flu can include:

• fever
• cough
• sore throat
• headache
• aches and pains in your joints or muscles
• chills
• stuffy nose
• diarrhea
• nausea and vomiting

Limitations of use

Rapivab is approved to treat only uncomplicated influenza infections. (With uncomplicated influenza, the flu isn’t severe enough to require hospitalization.) The drug hasn’t been shown effective in treating serious cases of influenza.

For example, in one study, researchers looked at people with serious influenza infections. Treatment with Rapivab was compared with that of a placebo (treatment with no active drug). The researchers found that Rapivab didn’t improve people’s flu symptoms any quicker than the placebo did.

Effectiveness for influenza

A clinical study showed that Rapivab was effective in treating uncomplicated influenza infections in adults. (With uncomplicated influenza, the flu isn’t severe enough to require hospitalization.)

People between the ages of 20 and 65 years participated in this study if they met specific requirements. These requirements were:

• fever of at least 100.4°F (38°C)
• a positive flu test
• at least two of the following symptoms, which began within 48 hours of receiving treatment in the study:
  • cough
  • chills or sweats
  • fatigue (lack of energy)
  • headache
  • malaise (overall feeling of being sick or unwell)
  • muscle aches or pains
  • nasal problems, such as stuffy nose
  • sore throat

The average age of participants in this study was 34 years. Of all the people included:

• 53% had been experiencing flu symptoms for less than 24 hours
• 99% had influenza type A

Everyone in the study was allowed to take medications for fever. In addition, people took either Rapivab or a placebo (treatment with no active drug). Of those taking Rapivab, some people were given a dose of 300 mg, and others were given a dose of 600 mg.

The researchers wanted to see if Rapivab improved people’s flu symptoms any quicker than the placebo did. (This was called “alleviation of symptoms.”) Specifically, alleviation of symptoms was reached when people’s flu symptoms either went away completely or were considered “mild” by the person.

The researchers found that compared with people taking the placebo:

• 50% of people taking Rapivab had their flu symptoms alleviated at least 21 hours sooner
• 50% of people taking Rapivab had their body temperature return to normal at least 12 hours sooner

Rapivab and children

In a clinical study, Rapivab was effective in treating influenza (the flu) in children ages 2 years and older. In this study, children took either Rapivab or another drug used to treat the flu called oseltamivir. (Oseltamivir is the generic form of Tamiflu). And all of the children were allowed to take medications for fever.

Children could participate in this study as long as they hadn’t had flu symptoms for more than 48 hours before starting treatment. Half of the children in the study were at least 7.9 years of age.

Of all the children included in the study:

• 58% had influenza type A
• 36% had influenza type B
• 6% had a “mix” of both influenza type A and influenza type B

Mainly, researchers wanted to see whether treatment with Rapivab was safe compared with that of oseltamivir. This was done by comparing the children’s side effects, vital signs, and lab tests. The results of this study showed that Rapivab was as safe as oseltamivir in treating flu in children.

The researchers also looked at how soon flu symptoms went away in each group of children. However, there wasn’t enough information to clearly show whether one drug was better than the other in resolving flu symptoms in children.

In addition, guidelines for treating the flu, established by the Infectious Disease Society of America (IDSA), recommend using drugs called neuraminidase inhibitors for early treatment of the flu in adults and children. Examples of neuraminidase inhibitors include both Rapivab and oseltamivir (Tamiflu).

Rapivab and alcohol

There aren’t any known interactions between Rapivab and alcohol.

However, you’ll likely want to avoid drinking alcohol while you have influenza (flu). This is because alcohol can cause your immune system to not work as well as usual. And this could make it harder for your body to fight off the flu, lengthening the amount of time that you’re sick.

If you have questions about whether it’s safe for you to consume alcohol while you’re taking Rapivab, talk with your doctor.

Rapivab interactions

Rapivab isn’t known to interact with any medications, herbs, supplements, or foods. But that doesn’t mean interactions can’t ever happen. However, Rapivab may interact with certain vaccines, as discussed below.

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 Rapivab, 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 possible drug interactions that may affect you, ask your doctor or pharmacist.

Rapivab and vaccines

You shouldn’t get a live influenza (the flu) vaccine either 2 weeks before or within 48 hours after receiving a dose of Rapivab.

This is because live flu vaccines contain a mild version of the live virus they’re meant to fight off. But, if you’re using a drug such as Rapivab, which kills flu viruses, it may kill the virus the vaccine contains. In this case, your immune system won’t recognize the vaccine. If your immune system doesn’t recognize the vaccine, the vaccine may not protect you from the flu in the way it’s supposed to.

Unlike live vaccines, you can get an inactivated flu vaccine at any time, regardless of whether you’ve received a dose of Rapivab. Inactivated flu vaccines don’t contain any live flu virus, so Rapivab won’t affect them. In this case, the inactivated flu vaccine will be able to help protect you from the flu in the usual way.

Currently, the only available live flu vaccine is the nasal vaccine called FluMist. (As a nasal vaccine, FluMist is given through your nose.)

Examples of inactivated flu vaccines that you get as an injection in the arm include:

• Fluzone
• Afluria

How Rapivab is given

You’ll receive Rapivab from a doctor or healthcare provider at a medical facility.

Rapivab comes as a colorless liquid solution inside vials. Your healthcare provider will give Rapivab to you as an intravenous (IV) infusion. With an IV infusion, the drug is injected into a vein, typically in your arm, over a period of time.

Rapivab infusions will usually last between 15 and 30 minutes.

When it’s given

Rapivab is only approved for treating influenza (the flu) in people who’ve had flu symptoms for no more than 2 days. Also, it’s only approved for treating uncomplicated influenza, which means the flu isn’t severe enough to require hospitalization.

You’ll only need to get one dose of Rapivab to treat influenza.

How Rapivab works

Rapivab is approved to treat uncomplicated influenza (the flu) in people ages 2 years and older. (With uncomplicated influenza, the flu isn’t severe enough to require hospitalization.)

Influenza is an infection that’s caused by the influenza virus. To learn more about this infection, see the “Rapivab uses” section above.

Rapivab contains the active drug peramivir. It’s is an antiviral drug that belongs to a class of medications called neuraminidase inhibitors.

Once inside your body, peramivir finds and attaches to the flu virus. Then, the drug blocks the actions of an enzyme (protein) called neuraminidase. This enzyme helps the flu virus multiply and spread in your body. (Viruses that multiply are making more viruses.)

This is how Rapivab helps your body fight off the flu.

How long does it take to work?

Rapivab begins working as soon as it enters your body. And it reaches its highest level inside your body after you’ve received your full dose of the drug.

It’s not known exactly how soon you might notice Rapivab working to treat the flu. But in clinical studies, researchers found that compared with people taking a placebo (treatment with no active drug):

• 50% of people taking Rapivab had their flu symptoms reduced at least 21 hours sooner
• 50% of people taking Rapivab had their body temperature return to normal at least 12 hours faster

Rapivab and pregnancy

It isn’t known if Rapivab is safe to take during pregnancy. There isn’t enough information about using this drug in pregnant people.

Animal studies have shown differing results. For instance, the results of one study that involved giving Rapivab to pregnant rats found it did not harm the fetus or pregnant female. However, other studies in pregnant rats and rabbits did highlight problems when Rapivab was used. Specifically, premature birth, pregnancy loss, and problems with kidney development in fetuses were seen.

However, it’s important to note that animal studies don’t always predict what will happen in humans. The animals in these studies were receiving doses of Rapivab that are much higher than the typical dose used in people.

If you have questions about using Rapivab during pregnancy, talk with your doctor. Also, keep in mind that the risk of complications from influenza (the flu) is higher during pregnancy. So, your doctor will work to find the best flu treatment option for you, if needed.

Rapivab and birth control

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

For more information about taking Rapivab during pregnancy, see the “Rapivab and pregnancy” section above. If you have questions about your birth control needs while taking Rapivab, talk with your doctor.

Rapivab and breastfeeding

It isn’t known whether it’s safe to take Rapivab while breastfeeding. This is because studies haven’t been done to see if Rapivab passes into human breast milk. There are no studies to show whether the drug can cause side effects in a child who breastfeeds.

Animal studies have shown that Rapivab passes into the milk of rats. But it’s not known what effect, if any, the drug had on the rats who consumed this milk. And keep in mind that animal studies don’t always predict what will happen in people.

If you have questions about taking Rapivab while breastfeeding, talk with your doctor.

Common questions about Rapivab

Here are answers to some frequently asked questions about Rapivab.

Does Rapivab cure the flu or just help reduce symptoms of the flu?

Rapivab isn’t a cure for influenza (the flu). But in clinical studies, the drug was shown to alleviate (reduce) symptoms of the flu faster than a placebo did. (A placebo is a treatment with no active drug.)

In one study of adults with the flu, researchers found that compared with people taking placebo (treatment with no active drug):

• 50% of people taking Rapivab had their flu symptoms reduced at least 21 hours sooner
• 50% of people taking Rapivab had their body temperature return to normal at least 12 hours faster

If you have additional questions about your treatment options for an influenza infection, talk with your doctor.

Can I get a flu vaccine if I’ve received Rapivab?

This depends on the type of influenza (the flu) vaccine you’ll be getting. You should avoid getting a live flu vaccine within 48 hours of getting a dose of Rapivab. However, you can get an inactivated flu vaccine anytime around receiving Rapivab if your doctor recommends it.

Inactivated flu vaccines are given with a needle. And unlike live flu vaccines, they don’t contain any live flu virus. When you get an inactivated flu shot, your immune system gets exposed to a dead form of the flu virus. This activates your immune system to make antibodies against the strains of flu contained in the vaccine. (Antibodies are proteins that help your body fight infections, such as influenza.) This way, if you’re exposed to the flu virus again, your body will be more prepared to fight it off.

The live flu vaccine, called FluMist, is given as a nasal spray. It’s made using a weakened form of live flu virus. If you get this flu vaccine too soon after receiving a dose of Rapivab, the vaccine may not work as well as usual. This is because Rapivab will still be active in your body. And the drug may kill the virus in the vaccine before your body becomes immune to the virus.

If you have questions about Rapivab and flu vaccines, talk with your doctor or pharmacist.

Am I still contagious with the flu once I’ve taken Rapivab?

Yes, you may still be contagious even after taking a dose of Rapivab. When you’re contagious, you’re able to pass an infection on to other people.

Rapivab is used to treat influenza (the flu), which is a highly contagious infection. It’s caused by a virus that easily spreads between people.

A person with influenza can pass it on to someone else when they cough, sneeze, or talk. Rapivab helps fight off the virus inside of your body. But even with treatment, you may still be able to pass the flu to others around you.

In general, people with the flu are contagious for 5 to 7 days after their flu symptoms begin. And this is the case even if they start to feel better and have fewer symptoms during this time.

There are certain things you can do to help reduce your risk of spreading the flu to others while you’re sick. These include:

• avoid touching your face, especially your eyes, mouth, and nose
• cover your face when you cough or sneeze
• stay home while you’re feeling sick
• wash your hands often

If you have questions about how long you may be contagious with the flu, talk with your doctor.

Is it safe for older people to take Rapivab?

To date, there’s no information showing that Rapivab isn’t safe for older people to take.

Clinical studies of the drug didn’t include enough people ages 65 years and older, so researchers can’t say for sure whether the drug affects older people differently. However, Rapivab didn’t appear to significantly affect older people differently during these trials. So, Rapivab is currently considered safe for older people to take.

If you have questions about the safety differences in flu treatments given your age, talk with your doctor.