Baloxavir marboxil is a single-dose oral anti-influenza drug with a favorable overall safety profile. This article summarizes its common adverse effects, management strategies, and storage requirements for reference.

What are the common adverse effects?

1. Common adverse reactions in clinical trials

In adult and adolescent patients with influenza, adverse events with an incidence ≥1% include: diarrhea, bronchitis, nausea, sinusitis, and headache.

2. Pediatric patients

In a study of children aged 1 to 12 years, no drug-related adverse reactions were observed in patients receiving the recommended dose of baloxavir marboxil.

3. Serious adverse reactions identified post-marketing

The following reactions are voluntary reports from post-marketing experience; incidence is unknown and caution is required:

(1) Allergic reactions: swelling of the face, eyelids, or tongue; dysphonia; angioedema; anaphylaxis; and shock.

(2) Skin reactions: rash, urticaria, erythema multiforme.

(3) Gastrointestinal reactions: vomiting, bloody diarrhea, melena, colitis.

(4) Neuropsychiatric symptoms: delirium, abnormal behavior, hallucinations.

Management of adverse effects

1. Management of diarrhea

(1) Most cases are mild and usually resolve on their own.

(2) Maintain adequate fluid intake to prevent dehydration; avoid greasy and irritating foods.

(3) If diarrhea is severe or bloody, seek immediate medical attention.

2. Managing nausea

(1) Symptoms are typically mild and transient.

(2) May be taken with food to reduce stomach discomfort; avoid taking on an empty stomach.

(3) If nausea is significant, drink small amounts of water frequently and eat a bland diet.

3. Emergency management of allergic reactions

(1) If any symptoms suggestive of allergy such as swelling of the face/tongue, difficulty breathing, or rash with itching occur, discontinue the drug immediately and seek medical attention.

(2) Severe cases may present with anaphylaxis requiring emergency treatment.

4. Abnormal behavior or hallucinations

If the patient (especially children) develops delirium, abnormal behavior, or hallucinations, discontinue the drug and notify the physician promptly. Avoid accidental injury due to altered mental status.

5. Recognizing the risk of bacterial infection

(1) Baloxavir marboxil is effective only against influenza virus.

(2) If symptoms persistently worsen, fever returns after defervescence, or purulent sputum appears, consider secondary bacterial infection and seek medical evaluation promptly.

Drug storage requirements

1. Temperature conditions

(1) Keep tightly closed and store at not more than 25°C.

(2) Avoid high-temperature environments.

2. Packaging requirements

(1) Keep in original packaging (blister pack); remove only when taking a dose.

(2) Protect from moisture.

3. Storage location

Keep out of reach of children to prevent accidental ingestion.