Propranolol pharmacokinetics during the menstrual cycle.

The pharmacokinetics of propranolol during menstruation and in the mid menstrual cycle have been studied in nine young women taking a single 80 mg tablet on each occasion. There were wide between-individual differences in the serum concentration at any given time (4-5 fold at peak concentrations) but the serum concentration time curves within individuals showed only mild variations. The differences between the average pharmacokinetic parameter estimates for the group did not differ significantly between the two periods of study.