Peramivir

Approved Uses

Peramivir is used to treat acute, uncomplicated influenza (the flu) caused by influenza A and B viruses. It is approved for use in adults and pediatric patients 6 months of age and older.

Timing of Treatment

This medication is most effective when started as soon as possible after flu symptoms begin. It is specifically indicated for patients who have been symptomatic for no more than 48 hours.

Important Considerations

• Type of Infection: Peramivir only treats infections caused by influenza viruses. It does not work for the common cold or infections caused by bacteria.
• Prevention: This drug is used to treat an active flu infection; it is not used to prevent the flu before or after exposure to the virus.
• Vaccination: Peramivir is not a substitute for the annual flu vaccine.

Mechanism of Action

Peramivir is an antiviral medicine classified as a neuraminidase inhibitor. It works by interfering with the way the influenza virus spreads within the respiratory system.

When a person has the flu, the virus enters cells in the body to make copies of itself. To release these new virus particles so they can infect other healthy cells, the virus uses a specific enzyme called neuraminidase. Peramivir binds to this enzyme and blocks its activity.

By inhibiting this enzyme, peramivir provides the following effects:

• Prevents Viral Release: The new virus particles remain trapped within the infected cells and cannot spread to neighboring cells.
• Slows Infection: Because the virus cannot spread as easily, the overall viral load in the body is reduced.
• Shortens Illness: By limiting the spread of the virus early on, the medication helps the immune system clear the infection faster, which can shorten the duration of flu symptoms.

This medication is effective against both influenza A and influenza B. It does not kill the virus directly but prevents it from multiplying and spreading, which allows the body's natural defenses to work more effectively.

Common Side Effects

• Diarrhea
• Nausea or vomiting
• Constipation
• Insomnia or trouble sleeping

Serious Side Effects

Seek medical help immediately if you notice any of the following serious symptoms:

• Allergic reactions: Hives, skin rash, swelling of the face, lips, or tongue, and difficulty breathing.
• Severe skin conditions: Red or purple skin rash that spreads and causes blistering or peeling (such as Stevens-Johnson syndrome).
• Neuropsychiatric events: Confusion, delirium, hallucinations, or abnormal behavior. These symptoms are most frequently reported in children and teenagers.
• Liver issues: Yellowing of the skin or the whites of the eyes (jaundice).

Some patients may also experience a decrease in certain white blood cell counts (neutropenia) or increased liver enzymes, which are typically monitored by a healthcare provider through blood tests.

Serious Allergic Reactions

Severe allergic reactions, including anaphylaxis, have been reported with the use of peramivir. Additionally, serious and potentially life-threatening skin conditions such as Stevens-Johnson syndrome and toxic epidermal necrolysis can occur. If a skin rash, hives, or signs of a severe allergic reaction develop, the medication should be stopped and medical attention sought immediately.

Neuropsychiatric Events

Influenza can be associated with a variety of neurologic and behavioral symptoms. Patients with the flu, particularly children and adolescents, may be at an increased risk for neuropsychiatric events while taking neuraminidase inhibitors like peramivir. These events may include:

• Delirium
• Hallucinations
• Confusion
• Abnormal behavior
• Self-injury

Patients should be closely monitored for any signs of unusual behavioral changes throughout the treatment period. These events often have an abrupt onset and rapid resolution.

Limitations of Use

Peramivir is an antiviral medication specifically for the influenza virus; it does not treat bacterial infections. Bacterial infections may begin with flu-like symptoms or occur as a complication during the course of the flu. If a bacterial infection is suspected or present, it must be treated separately.

The effectiveness of peramivir has not been established for patients with serious influenza infections that require hospitalization. Furthermore, this medication is not a substitute for receiving an annual influenza vaccination.

Contraindications

Peramivir is contraindicated in patients with a known history of severe allergic reactions to any component of the medication. It should not be administered to individuals who have experienced a previous hypersensitivity reaction to peramivir.

Pregnancy

There are no adequate and well-controlled studies regarding the use of peramivir in pregnant women. It is currently unknown whether the drug can cause harm to a developing fetus or affect the ability to have children in the future.

Because pregnant women are at an increased risk for severe complications from influenza, healthcare providers may consider peramivir if the potential benefit to the mother justifies the potential risk to the fetus.

Breastfeeding

It is not known if peramivir is excreted in human breast milk. Because many medications can pass into breast milk, caution is recommended when peramivir is administered to someone who is nursing.

If you are pregnant, planning to become pregnant, or breastfeeding, discuss your treatment options and any concerns with your healthcare provider.

Available Forms

Peramivir is available in the following form:

• Intravenous Solution: A clear, colorless liquid supplied in single-use vials for administration into a vein.

This medication is administered as an infusion (IV) by a doctor or nurse in a medical setting, such as a hospital or clinic.

FDA Approval and Indications

The U.S. Food and Drug Administration (FDA) approved peramivir in December 2014. It is indicated for the treatment of acute uncomplicated influenza in patients 6 months of age and older who have been symptomatic for no more than two days. It is administered as a single intravenous dose by a healthcare provider.

Regulatory History and Scope

While originally approved for adults, the FDA expanded the indication to include pediatric patients aged 2 to 12 years in 2017, and later to infants as young as 6 months in 2021. The drug is not approved for the prevention of influenza or for the treatment of patients with complicated or chronic underlying medical conditions.

Safety Monitoring and Warnings

There are no boxed warnings for peramivir. However, the FDA requires monitoring for certain serious adverse reactions identified during postmarketing surveillance, including:

• Neuropsychiatric Events: Patients with influenza, particularly children and adolescents, may be at an increased risk of seizures, confusion, or abnormal behavior.
• Serious Skin Reactions: Rare but severe skin conditions, such as Stevens-Johnson syndrome and toxic epidermal necrolysis, have been reported.
• Hypersensitivity: Severe allergic reactions, including anaphylaxis, can occur.

The FDA continues to monitor the safety profile of peramivir through postmarketing reports to ensure the benefits of the medication outweigh its risks.

Initial FDA Approval

The U.S. Food and Drug Administration (FDA) approved peramivir in December 2014. It was the first neuraminidase inhibitor available in an intravenous (IV) formulation for the treatment of acute uncomplicated influenza in adults 18 years and older. The approval was based on clinical trials showing that a single dose could reduce the duration of flu symptoms when administered early.

Expanded Use in Children

Following its initial approval for adults, the FDA expanded the authorized use of peramivir to younger populations:

• 2017: The FDA approved the medication for use in pediatric patients aged 2 to 17 years.
• 2021: The approval was further extended to include infants and children as young as 6 months of age.

Approved Indications and Timing

Peramivir is FDA-approved specifically for the treatment of acute uncomplicated influenza in patients who have been symptomatic for no more than two days. It is not approved for the prevention of the flu or for use in patients with serious influenza requiring hospitalization.

History of Emergency Use

Before its formal approval in 2014, peramivir was made available under an Emergency Use Authorization (EUA) during the 2009 H1N1 influenza pandemic. This allowed healthcare providers to use the drug for certain hospitalized patients before the full clinical review process for its current indication was completed.