What to Know About Rapivab (Peramivir)

A One-Time Dose IV Treatment for the Flu

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Rapivab (peramivir) is an antiviral medication used to treat a flu infection caused by the influenza A or influenza B virus. It is administered as a one-time dose intravenously (IV, in a vein). Because Rapivab is an IV antiviral, it is considered useful for people who have a hard time taking medication by mouth due to issues like severe nausea and vomiting. 

Peramivir may reduce the harmful effects of the virus on the body. Treatment with this medication may shorten the duration of the flu and may reduce the symptoms caused by the infection.

This medication is classified as a neuraminidase inhibitor—it binds to neuraminidase, which is a viral enzyme. This biochemical action interferes with release of the virus from your infected cells so the infectious microorganism can’t continue to proliferate in your body and make you feel sick.

Intravenous medication
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Rapivab is approved for adults and children over the age of 2. It is indicated as a treatment for uncomplicated influenza A and influenza B when symptoms have lasted for two days or less.

Influenza A and influenza B are contagious viruses that cause the flu. These are generally considered community-acquired infections that can potentially affect any healthy person who catches it from other people, usually through respiratory droplets.

Influenza A is more common than influenza B, but the overall effects, transmission, and disease course of the two viruses are similar. Often, these infections resolve on their own without intervention, but they can make you feel sick and run down for a few days or weeks.

Symptoms of influenza A and influenza B include:

  • Low-grade fevers, usually between 99 degrees and 102 degrees F
  • Chills 
  • Muscle aches 
  • Fatigue
  • Sore throat 
  • Runny nose 
  • Dry eyes 
  • Decreased appetite 
  • Nausea, vomiting, abdominal discomfort

While there are tests that can confirm the presence of influenza A and influenza B, it is not required to confirm the diagnosis with a test.

If your healthcare provider makes a clinical diagnosis based on your symptoms, possibly associated with a recent outbreak of the influenza A or B, virus, they may prescribe Rapivab for you even without a confirmatory test. However, your health insurer might require verification of the diagnosis in order to pay for the treatment.

Keep in mind that it is generally advised to stay home from school, work, social gatherings, and public spaces where you would be in close proximity with other people who could catch your infection if your healthcare provider has told you that you could be contagious.


According to the manufacturer, Rapivab is not considered effective for treatment of complicated influenza that requires hospitalization. It does not directly treat symptoms such as fever and dehydration, although these symptoms may improve due to the medication’s effects of reducing viral proliferation in your body.

If you have uncomplicated influenza A or B, you may also need to use therapies besides Rapivab for treatment of your other symptoms, such as pain relievers and medications to lower your fever.

Off-Label Uses 

This medication has been used off label as a treatment for severe influenza A or B infections that require hospitalization. In these situations, other treatments, such as IV fluids and respiratory support, are also needed to manage the severe effects. 

It has also been used off-label for treating other viral infections such as H1N1, which is also referred to as the swine flu.

According to a 2020 article in the Journal of Cell Physiology, neuraminidase inhibitors such as peramivir are not recommended for the treatment of COVID-19.

Before Use 

It is safe to use this medication if you have had or are going to have a flu vaccine. However, if you will have a live vaccine, peramivir can interfere with the replication of the virus and can reduce the protective effect of the vaccine.

  • You should not use this medication if you have had any allergic reaction to peramivir or other neuraminidase inhibitors.
  • Caution is recommended in considering this treatment for women who are pregnant or breastfeeding. 

Precautions and Contraindications 

This medication needs to be used with caution for people who have kidney disease, and the dosing may need to be adjusted.

Other Neuraminidase Inhibitors 

Peramivir is also available by the brand names Rapiacta and Peramiflu in other countries outside the US. 

There are several other antiviral treatments in the neuraminidase inhibitor category, including Tamiflu (oseltamivir), which is is taken by mouth for the treatment of influenza A and influenza B. Relenza (zanamivir) and Inavir (laninamivir) are neuraminidase inhibitors that come in powder forms and are taken by nasal inhalation for the treatment of influenza A and B.


Rapivab is used as one-time injection during a flu illness, ideally within two days after symptoms begin. It is administered IV over the course of 15 to 30 minutes.

Rapivab comes in single use vials containing 200 milligrams (mg) of medication in 20 milliliters (mL) of solution (10 mg/mL) and it is supplied in cartons of three single-use vials.

  • The dose for adults and children 13 and older is 600 mg per infusion. 
  • Children 12 and younger are dosed by weight in kilograms (kg). They should take 12 mg/kg, not to exceed 600 mg, per infusion. 


The dose needs to be adjusted for people who have kidney failure. According to the manufacturer, adjustments are based on creatinine clearance.

For creatinine clearance:

  • Between 30-49 mL/min: Adults and adolescents 13 years and older should take 200 mg of the medication. Children 2-12 years old should use 4 mg/kg of the medication
  • Between 10-29 mL/min: Adults and adolescents 13 years and older should take 100 mg of the medication. Children 2 to 12 years old should use 2 mg/kg of the medication.

How to Take and Store 

Rapivab should be stored at 20 to 25 C (68 to 77 F) before dilution. The medication solution should be diluted in 0.9% or 0.45% sodium chloride, 5% dextrose, or lactated Ringer’s to a maximum volume of 100 mL.

The diluted solution should be administered immediately or stored at a temperature of 2 to 8 C or 36 to 46 F for up to 24 hours. If refrigerated, the diluted solution should reach room temperature before use and then must be administered immediately.

Side Effects 

This medication is generally well-tolerated. However, it can cause side effects. If you or your child will be using it, it’s a good idea to familiarize yourself with the side effects so you can call your healthcare provider if you start to notice any.


Diarrhea is the most common side effect, and it is often self-limited without serious consequences.


Serious side effects are rare and include: 

  • Severe anaphylactic (allergic) reactions 
  • Skin reactions
  • Erythema multiforme
  • Stevens-Johnson Syndrome 
  • Delirium 
  • Hallucinations 
  • Abnormal behavior

Warnings and Interactions 

Rapivab should not be given with any other medications during the infusion and other medications should not be mixed with the infusion.

Resistant infectious microorganisms can emerge with the use of any treatment that targets a certain infectious organism. According to the manufacturer, cross-resistance can develop between peramivir, oseltamivir, and zanamivir, so these medications should not be used excessively. 

5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration. Rapivab label.

  2. Cies JJ, Moore WS 2nd, Enache A, Chopra A. Peramivir for influenza A and B viral infections: A pharmacokinetic case series. Pharmacotherapy. 2019;39(11):1060-1065. doi:10.1002/phar.2330

  3. Peramivir for influenza. Aust Prescr. 2019;42(4):143. doi: 10.18773/austprescr.2019.047

  4. Yousefi B, Valizadeh S, Ghaffari H, Vahedi A, Karbalaei M, Eslami M. A global treatments for coronaviruses including COVID-19 [published online ahead of print, 2020 May 11]. J Cell Physiol. 2020;10.1002/jcp.29785. doi:10.1002/jcp.29785

  5. Chen JY, Wei SK, Lai CC, Weng TS, Wang HH. A meta-analysis comparing the efficacy and safety of Peramivir with other neuraminidase inhibitors for influenza Treatment. Medicina (Kaunas). 2020;56(2)February 5. doi:10.3390/medicina56020063

By Heidi Moawad, MD
Heidi Moawad is a neurologist and expert in the field of brain health and neurological disorders. Dr. Moawad regularly writes and edits health and career content for medical books and publications.