Baloxavir marboxil

Baloxavir marboxil is an antiviral polymerase endonuclease inhibitor used for the treatment of acute uncomplicated influenza. It is a prodrug that is converted by hydrolysis to baloxavir, the active form that exerts anti-influenza virus activity. Baloxavir inhibits the endonuclease activity of the polymerase acidic (PA) protein, an influenza virus-specific enzyme required for viral gene transcription, resulting in inhibition of influenza virus replication.

It is taken as a single oral dose within 48 hours of symptom onset. Dosage is weight-based: 40 mg (two 20 mg tablets) for patients weighing 40 to <80 kg, and 80 mg (two 40 mg tablets) for patients weighing ≥80 kg.

Common side effects include diarrhea, bronchitis, nausea, sinusitis, and headache. Allergic reactions are rare.

• Acute uncomplicated influenza in patients 12 years and older who have been symptomatic for no more than 48 hours
• Otherwise healthy patients or those at high risk of developing influenza-related complications
• Post-exposure prophylaxis (PEP) of influenza in patients 12 years and older following contact with an individual who has influenza

Baloxavir marboxil is an antiviral polymerase endonuclease inhibitor. It is a film-coated tablet for oral administration. Baloxavir marboxil is a prodrug that is converted by hydrolysis to baloxavir, the active form that exerts anti-influenza virus activity.

Baloxavir inhibits the endonuclease activity of the polymerase acidic (PA) protein, an influenza virus-specific enzyme in the viral RNA polymerase complex required for viral gene transcription, resulting in inhibition of influenza virus replication.

Baloxavir inhibits the cap-dependent endonuclease of the viral polymerase, blocking viral replication. It interferes with the 'cap snatching' process, where viruses hijack the host mRNA transcription system to allow viral RNA synthesis.

Adults and Adolescents (12 years and older):

• Weight 40 to <80 kg: 40 mg (two 20 mg tablets) as a single dose
• Weight ≥80 kg: 80 mg (two 40 mg tablets) as a single dose

Hepatic Impairment: Moderate (Child-Pugh B) to normal: No clinically meaningful pharmacokinetic differences observed; Severe: Not studied.

Renal Impairment (CrCl >50 mL/min): No clinically meaningful effect identified; Severe: Not studied.

Take as a single oral dose within 48 hours of influenza symptom onset. May be taken with or without food. Avoid coadministration with dairy products, calcium-fortified beverages, or supplements containing calcium, iron, magnesium, selenium, or zinc.

This is a single-dose medication, so the concept of a missed dose does not apply. However, if a dose is not taken for any reason, consult your doctor as soon as possible.

• Diarrhea (3%)
• Bronchitis (3%)
• Nausea (2%)
• Sinusitis (2%)
• Headache (1%)

Rare: Anaphylaxis, angioedema, urticaria, erythema multiforme

• No evidence of efficacy in illnesses caused by pathogens other than influenza viruses
• Serious bacterial infections may begin with influenza-like symptoms or may occur as a complication of influenza
• If allergic reactions (anaphylaxis, angioedema) occur, initiate appropriate treatment
• Monitor for secondary bacterial infections and treat appropriately

• Hypersensitivity to Baloxavir marboxil or any component

• Polyvalent cations (calcium, aluminum, magnesium, iron, selenium, zinc): Baloxavir (active metabolite) may form a chelate with polyvalent cations. Avoid coadministration with dairy products, calcium-fortified beverages, antacids, or supplements.
• Live attenuated influenza vaccine (LAIV): Coadministration may inhibit viral replication of LAIV, resulting in decreased vaccine effectiveness.

Avoid taking with dairy products, calcium-fortified beverages, or supplements containing calcium, iron, magnesium, selenium, or zinc.

[CONSULT YOUR DOCTOR] Pregnant women are at higher risk of severe complications from influenza. There are no adequate well-controlled studies in pregnant women. Animal studies showed no adverse developmental effects. Use only if clearly needed.

[CONSULT YOUR DOCTOR] No data are available on the presence of baloxavir marboxil in human milk. Baloxavir and its metabolites were present in milk of lactating rats. Consider the benefits of breastfeeding along with the mother's clinical need.

Safety and efficacy have not been established in pediatric patients under 12 years of age or weighing less than 40 kg. For patients 12 years and older weighing at least 40 kg, adult dosing applies.

No dose adjustment is needed for elderly patients.

Renal Impairment (CrCl >50 mL/min): No clinically meaningful effect identified; Severe renal impairment not studied.

Hepatic Impairment: Moderate (Child-Pugh B) to normal: No clinically meaningful differences observed; Severe hepatic impairment not studied.

There is no specific antidote for baloxavir overdose. Treatment should consist of general supportive measures including monitoring of vital signs and observation of the patient's clinical status.

Store below 30°C, away from light and moisture. Keep out of reach of children.

Baloxavir marboxil