Rhinovirus

Pirodavir is a potent, broad-spectrum picornavirus inhibitor. Pirodavir inhibits 80 of the 100 human rhinovirus (HRV) strains tested at a concentration of 64 ng/mL. In that same study, Pirodavir is also effective in inhibiting 16 enteroviruses, with a mean 80% inhibitory concentration (IC ₈₀ ) of 1,300 ng/mL. Pirodavir inhibits enterovirus 71 replication with an IC ₅₀ of 5,420 nM and an IC ₉₀ of >13,350 nM. Pirodavir inhibits 56 rhinovirus laboratory strains and three of the clinical isolates tested. Pirodavir inhibits 59% of the serotypes and isolates with IC ₅₀ s of <100 nM. Pirodavir concentrations of 16 and 4μg/mL reduces cell growth by 66% (s.e.m. 0.75) and 28% (s.e.m. 0.25), respectively. Lower concentrations (1μg/mL) of Pirodavir are not inhibitory for cell growth. The 50% cytotoxic concentration of pirodavir for logarithmic cell growth at 37°C is 7μg/mL. Under the conditions of the antiviral assay (confluent HeLa cells at 33°C), the 50% cytotoxic concentration is >50μg/mL.