Adult & childn >5 yr 50 mg/kg/day, may be increased to 100 mg/kg/day. Doses should be taken in 4-6 divided doses. 
Childn <5 yr 50 mg/kg/day, may be increased to 100 mg/kg/day. Duration of therapy: 
Short term acute viral infection Doses should be continued 1 to 2 days after the symptoms subside. 
Long term acute viral infection Doses should be continued 1-2 wk after the symptoms subside.