Increased dipyridamole plasma concentrations associated with salicylate administration. Relationship to effects on platelet aggregation in vivo

Dipyridamole, in relatively low doses, when used in combination with aspirin was shown to be effective in normalizing reduced platelet survival seen in patients with prosthetic heart valves, whereas either drug, when tested alone, was ineffective. To determine whether this combined drug effect was due to a synergism of the two drugs or due to an alteration in the pharmacokinetics of one drug in the presence of the other, we examined the effects …