baloxavir marboxil

Action and Spectrum

Mechanism of action

It is an antiviral medication used to treat influenza (the flu). Its action is to inhibit the replication of the influenza virus by blocking its main protease, called PA, which is necessary for the virus to replicate and spread

Spectrum

The spectrum of activity of baloxavir marboxil covers both influenza A and B viruses, the two main types of influenza viruses that cause seasonal flu epidemics. It is effective against many influenza viruses, including those resistant to other antiviral drugs such as neuraminidase inhibitors (e.g., oseltamivir, zanamivir)

Drug Interaction

Adverse Reaction

Frequency defined:

1-10%

Bronchitis (2%)

nasopharyngitis (1%)

diarrhea (3%)

nausea (1%)

headache (1%)

Post-marketing reports

skin disorders

delirium

hallucinations

abnormal behavior

vomiting

melena

bloody diarrhea

colitis

Black Box Warning

Contraindication / Caution

Contraindications

It is contraindicated in patients with a known hypersensitivity to baloxavir marboxil or any of its components. Before starting treatment with baloxavir marboxil, it is essential to inform the healthcare provider about any allergies or previous medication adverse reactions.

Caution

• Pregnancy and breast-feeding: The safety of baloxavir marboxil in pregnant women and nursing mothers has not been established, so it should be used only if the potential benefits outweigh the risks
• Pediatric population: The safety and efficacy of baloxavir marboxil in children under 12 years of age have not been established
• Renal impairment: It is cleared from the body through the kidneys, so patients with moderate to severe renal impairment may require a lower dose or closer monitoring
• Drug interactions: It may interact with other medications, including prescription and over-the-counter drugs, vitamins, and herbal supplements. It is essential to inform the healthcare provider about all medications and supplements being taken before starting treatment with baloxavir marboxil
• Adverse reactions: It may cause adverse reactions such as diarrhea, nausea, and elevated liver function tests. These reactions are usually mild to moderate and resolve without treatment

Pregnancy / Lactation

Pregnancy consideration: Insufficient data available

Lactation: Excretion of the drug in human breast milk is unknown

Pregnancy category:

Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester.

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women.

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.

Category D: adequate data available with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.

Category N: There is no data available for the drug under this category

Pharmacology

Pharmacology

Cap-dependent endonucleases are enzymes involved in certain viruses’ replication process. Antiviral drugs that inhibit these endonucleases can prevent the replication of the virus by interrupting the process of cap snatching, a method by which the virus hijacks the host’s mRNA transcription system for viral RNA synthesis.

Pharmacodynamics

The pharmacodynamics of baloxavir marboxil involve the drug’s interaction with the target enzyme, cap-dependent endonuclease, which is essential for the replication of influenza viruses. It binds to the target enzyme, preventing it from cleaving the host cell’s mRNA, thus disrupting the replication process of the virus.

Pharmacokinetics

• Absorption: It is well absorbed following oral administration, with a peak plasma concentration of 96.4 ng/mL (40-mg dose) and 107 ng/mL (80-mg dose) reached at 4 hours. Food can decrease the peak plasma concentration by 48% and the area under the concentration-time curve (AUC) by 36%
• Distribution: It is highly protein-bound, with 92.9-93.9% of the drug bound to plasma proteins. Its volume of distribution (Vd) is 1180 L
• Metabolism: It is primarily metabolized by the enzyme UGT1A3, with minor metabolism by CYP3A4. It is a prodrug almost completely converted to its active metabolite, baloxavir
• Elimination/Excretion: It has an elimination half-life of 79.1 hours, a clearance of 10.3 L/hr, and is primarily excreted in the feces (80.1%) and urine (14.7%)

Adminstartion

Administration

• It is an antiviral drug that is indicated for treating uncomplicated acute influenza (flu) in patients 12 years of age and older who have had symptoms for no more than 48 hours.
• It is available as an oral tablet and is administered once daily. The recommended dose is 40 mg for patients weighing 40 kg or less and 80 mg for those weighing more than 40 kg. baloxavir marboxil should be taken with or without food, but if taken with food, it can decrease its peak plasma concentration.
• It is essential to follow the recommended dose and schedule for baloxavir marboxil and any other instructions provided by a healthcare provider. If a dose is missed, it should be taken as soon as possible unless it is close to the time of the next dose, in which case the missed dose should be skipped

Patient Information Leaflet

Patient information leaflet

Generic Name: baloxavir marboxil

Pronounced: [ ba-LOX-a-vir-mar-BOX-il]

Why do we use baloxavir marboxil?

It is a medication used to treat uncomplicated acute influenza (flu) in patients 12 years of age and older who have had symptoms for no more than 48 hours