Fig. 1

Mean ± SD plasma clenbuterol concentrations vs time following chronic (a) low dose and (b) high dose administration of (a) 0.8 μg/kg Ventipulmin® BID for 30 days to 22 racing fit Thoroughbred horses and (b) Ventipulmin® (0.8 μg/kg, BID for 3 days, 1.6 μg/kg, BID for 3 days, 2.4 μg/kg, BID for 3 days and 3.2 μg/kg, BID for 21 days) to 6 racing fit Thoroughbred horses. Arrows indicate administration of a new dose