In this article, we will discuss Antiviral Drugs (Part-III). So, let’s get started.
Ribavirin Dilute 6 g of ribavirin in 300 ml of sterile water and nebulize for 12–18 hr/d or 2 g over 2 hr 3 times daily for 3-7 days. Oral dose 15-20 mg/kg/day q 6-8 hr for 7-10 days up to maximum dose of 1800 mg/day.
Adult dose: Herpes simplex 200 mg q.i.d. for 7-10 days; influenza 200 mg q.i.d. for 3-5 days; chronic hepatitis C 1000 mg daily (400 mg morning, 600 mg evening) for 48 weeks (genotype 1) and for 24 weeks (genotype 2 and 3).
Indication: RSV infection (bronchiolitis, pneumonia) and chronic hepatitis C (along with IFN-α 2b).
(Ribavin cap, rebetol, virazide tabs 100 mg, 200 mg, syrup virazide, ribavin 50 mg/5 ml).
Trifluridine Topical use for herpes simplex conjunctivitis and keratitis q 12 hr (with IV aciclovir or vidarabine) 1 drop in each eye every 2 hours (maximum 9 drops) for 7 days. Following re-epithelialization, 1 drop every 4 hours (minimum 5 drops/day). Do not exceed treatment beyond 21 days.
(Viroptic ophthalmic drops 1%).
Valganciclovir It is a prodrug of ganciclovir. CMV prophylaxis
in post-transplant patients (start within 10 days of transplant): 15-18 mg/kg/dose q 6 hr oral for 100 days. CMV retinitis in adults: 900 mg/dose 12 hourly for 21 days (induction), then 900 mg/dose q 6 hr (maintenance). 250 mg/m²/d for 3 weeks, then 125 mg/mp/d oral for another 3 weeks for CMV hepatitis and biliary atresia due to CMV.
(Valcept, valgan, valcyte, vagacyte, valgaids, valniche, valstead tab 450 mg).
Zanamivir It is recommended for prophylaxis and treatment of H1N1 infection in children above 7 years of age. It is available in powder form with an inhalation device. For treatment, give inhalation of 10 mg twice a day for 5 days within 48 hours of onset of symptoms. For prophylaxis, inhalation should be started within 36 hours of exposure with a daily single dose of 10 mg for 7 days.
Side Effects: Inhalation may cause severe bronchospasm in patients with reactive airway disease. Common adverse effects include dizziness, behavior disturbances and severe allergic reactions including angioedema.
(Relenza, virenza and Z Flu DPI are available to provide 5 mg zanamivir per actuation along with a delivery device for inhalation)