The effect of cimetidine on the pharmacokinetics of salicylic acid.

The pharmacokinetics of the interaction between salicylic acid and cimetidine was investigated in 11 healthy male and female volunteers. The plasma concentrations of total and free salicylic acid were measured. The kinetic disposition of salicylic acid after multiple administration of cimetidine (1 g per day) showed two modifications: the elimination rate was slower and plasma clearance was reduced. The corresponding area under concentration-time curves was always significantly greater. These differences were the same in both sexes. The rate of absorption, peak salicylate concentration and plasma protein binding of salicylic acid in the presence of cimetidine were not changed.