baloxavir

REMS

Treatment of acute uncomplicated influenza in patients who have been symptomatic for ≤48 hr and who are otherwise healthy or at high risk of developing influenza-related complications.
Postexposure prophylaxis of influenza following contact with an individual who has influenza.

Action ⬆ ⬇

Inhibits the endonuclease activity of the polymerase acidic protein in the viral RNA polymerase complex that is required for viral gene transcription, thereby resulting in inhibition of influenza virus replication.

Therapeutic effects:

Reduced duration of flu-related symptoms.

Pharmacokinetics ⬆ ⬇

Absorption: Administered as a prodrug (baloxavir marboxil), which is rapidly absorbed from the GI tract and converted by the liver to the active form, baloxavir.

Distribution: Extensively distributed to tissues.

Protein Binding: 93–94%.

Metabolism/Excretion: Rapidly metabolized by the liver by UGT1A3 to baloxavir, the active metabolite. Primarily excreted in feces (80%); 15% excreted in urine (3% as active metabolite).

Half-Life: 79 hr.

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
PO	unknown	4 hr	unknown

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity.

Use Cautiously in:

OB: Safety not established in pregnancy;
Lactation: Safety not established in breastfeeding;
Pedi: Children 5 yr ( risk of treatment-emergent resistance).

Adv. Reactions/Side Effects ⬆ ⬇

EENT: nasopharyngitis

GI: diarrhea, nausea

Neuro: headache

Misc: HYPERSENSITIVITY REACTIONS (INCLUDING ANAPHYLAXIS AND ANGIOEDEMA)

Interactions ⬆ ⬇

Drug-drug:

Medications containing divalent or trivalent cations, including calcium, iron, magnesium, selenium, or zinc, may ↓ absorption of baloxavir; avoid concurrent use.
May ↓ the therapeutic effect of the live-attenuated influenza vaccine.

Calcium in foods or dairy products may ↓ absorption of baloxavir; avoid concurrent administration.

Route/Dosage ⬆ ⬇

PO (Adults and Children ≥5 yr and ≥80 kg): 80 mg as a single dose (as tablets or oral suspension).
PO (Adults and Children ≥5 yr and 20–<80 kg): 40 mg as a single dose (as tablets or oral suspension).
PO (Adults and Children ≥5 yr and <20 kg): 2 mg/kg as a single dose (as oral suspension).

Availability ⬆ ⬇

Oral suspensionstrawberry flavor: 2 mg/mL
Tablets: 40 mg; 80 mg

Assessment ⬆ ⬇

Monitor influenza symptoms (sudden onset of fever, cough, headache, fatigue, muscular weakness, sore throat). Additional supportive treatment may be indicated to treat symptoms.
Monitor for signs and symptoms of hypersensitivity reactions (anaphylaxis, angioedema, urticaria, erythema multiforme) following therapy.

Implementation ⬆ ⬇

Administer as soon as possible after influenza symptom onset or exposure to influenza.
PO: Administer 2 tablets without regard to food within 48 hr of onset of symptoms. Avoid taking dairy products, calcium-fortified beverages, polyvalent cation-containing laxatives, antacids, or oral supplements (calcium, iron, magnesium, selenium, or zinc) at same time.
- Suspension may be used for patients with difficulty swallowing or who require enteral administration. Gently tap bottom of bottle to loosen granules (white to light yellow) and constitute with 20 mL of drinking water or sterile water. Swirl to mix granules evenly; do not shake. Solution is stable for 10 hr after constitution at room temperature; write expiration time and date on label. Measure dose with oral syringe to ensure correct dose; may require more than 1 bottle. Patient must sit upright when taking baloxavir; do not give while patient is lying down. Do not mix suspension with soft food or another liquid.
- For administration via feeding tube, draw up suspension with an enteral syringe. Flush with 1 mL of water before and after administration.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take baloxavir as directed. Advise patient to read Patient Information before taking baloxavir.
Advise patient to notify health care professional immediately if signs and symptoms of hypersensitivity reactions (rash; hives; difficulty breathing; swelling of lips, face, and throat) occur.
Advise patient to consult health care professional before receiving a live-attenuated influenza vaccine after taking baloxavir.
Advise patient that baloxavir is not a substitute for a flu shot. Patients should receive annual flu shot according to immunization guidelines.
Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking any new medications.
Rep: Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding. Pregnant women are at higher risk of severe complications from influenza, which may lead to adverse pregnancy and/or fetal outcomes, including maternal death, stillbirth, birth defects, preterm delivery, low birth weight, and small for gestational age.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇