Table 1.

Recommended dosage and schedule of influenza antiviral medications for treatment and chemoprophylaxis in Japan (as of 2016)

	Route of administration	Treatment		Chemoprophylaxisa
		Adult	Children	Adult	Children
Oseltamivir	Oral	75 mg twice daily, 5 days	a. 75 mg twice daily, 5 days (body weight ≥ 37.5 kg)b b. 2 mg/kg twice daily, 5 days (maximum 150 mg/day) (body weight < 37.5 kg)b	75 mg once daily, 10 daysc	2 mg/kg once daily, 10 days (maximum 75 mg/day)c
Zanamivir	Inhalation	10 mg twice daily, 5 days	10 mg twice daily, 5 days (≥5 years old)	10 mg once daily, 10 daysd	10 mg once daily, 10 days (≥5 years old)d
Peramivir	Intravenous infusion for 15–30 min	One 300 mg dose (maximum 600 mg per day), 1 daye	One dose at 10 mg/kg (maximum 600 mg/day), 1 daye	N/A	N/A
Laninamivir	Inhalation	One 40 mg dose, via inhalation	a. 40 mg single inhalation (≥10 years old) b. 20 mg single inhalation (<10 years old)	20 mg single inhalation daily, two successive days or oc	a. 20 mg single inhalation daily, two successive days, or one 40 mg single inhalation (≥10 years old) b. 20 mg single inhalation (<10 yeas old)c
Favipiravir	Oral	1600 mg twice daily as initial dose 600 mg twice daily for following 2–5 days	N/A	N/A	N/A

^aChemoprophylaxis is considered for family members or those sharing daily life with influenza patient and fulfill the conditions of (i) elderly over age of 65 years old, (ii) chronic respiratory diseases, and chronic cardiac diseases, (iii) metabolic disease such as diabetes mellitus, and (iv) renal dysfunction

^bAdministration to patients who aged 10–19 years is not recommended. Safety to children below 1 year old is not confirmed

^cRecommended to start within 48 h after known contact with influenza patient

^dRecommended to start within 1.5 days after known contact with influenza patient

^eSuccessive daily administration is allowed for patients in severe condition