A pharmacokinetic and platelet function study of the combined administration of metoprolol and sulfinpyrazone to healthy volunteers

In a double-blind study on healthy subjects who underwent three 3-week periods of treatment with metoprolol (M) + sulfinpyrazone (S), M + placebo, and S + placebo, pharmacokinetics and plasma levels of M were not affected by concurrent administration of S. Analysis of variance change-over demonstrated a significant difference between treatments only for serum uric acid levels. Analysis of post-treatment and baseline data within each treatment showed: decreased platelet count by M, lowered serum 6-keto PGF_1α by all three treatments, decreased serum TXB₂ generation and arachidonic acid-induced platelet aggregation by S + M. No negative interaction between S + M was found.