Table 1.

Antiviral therapy approved for treatment and prophylaxis of common respiratory viral infections.

Viral infection	Antiviral agents	Drug class/Mechanism of action	Dosage and duration of treatment regimen	Concerns for drug resistance
Influenza virus	Oseltamivir	NAI	75 mg orally twice daily Recommended duration is 5 days Longer duration (10 days) for immunocompromised individuals [8] Two inhalations (10 mg) twice daily for 5 days [8]	Influenza A(H1N1) virus strains H275Y substitution leads to resistance [10,11]
	Zanamavir	NAI	Intravenous zanamivir available through compassionate use program Single dose of 600 mg administered intravenously [8]	Influenza A (H1N1) with both an H275Y and an E119D or E119G NA substitution lead to resistance to zanamivir [12,13].
	Peramivir	NAI	Longer duration of 5 days in high-risk patients [9].	Influenza A(H1N1) virus with H275Y substitution leads to resistance to peramivir [14]
	Amantadine	M2 inhibitor	200 mg given once daily or 100 mg given twice daily over 24–48 h after symptoms resolve (duration of therapy is generally 5 days) [8]	Mutations of the pore-lining residues in the ion channel prevents adamantine and rimantadine from entering the channel
	Rimantadine	M2 inhibitor	100 mg twice daily for 5–7 days [8]
Respiratory syncytial virus	Ribavirin	Inhibits enzyme dehydrogenase and reduces the cellular deposits of guanidine necessary for viral growth [15]	Aerosolized ribavirin can be administered as 2 g for 2 h every 8 h or as 6 g over 18 h every day for 7–10 d [16] Oral ribavirin – loading dose of 600 mg followed by 200 mg every 8 h on the first day, 400 mg every 8 h the second day, and then escalation to a maximum of 30 mg/kg/day [16]	None reported
Parainfluenza virus	None licensed
Human rhinovirus	None licensed
Human Metapneumovirus	None licensed

NAI: neuraminidase inhibitors