LACK OF AN INTERACTION BETWEEN PROPRANOLOL AND SUMATRIPTAN

1 The effect of twice-daily dosing with propranolol on the pharmacokinetics and pharmacodynamics of a single oral dose of sumatriptan was investigated in 10 healthy male subjects. 2 Each subject received 7 days dosing with propranolol (80 mg twice daily) plus a single dose of sumatriptan (300 mg orally) on day 7; on another separate occasion, placebo was administered for 7 days plus a single dose of sumatriptan on day 7. There was at least a 7 day washout interval between the two periods of dosing. Pulse and blood pressure were measured up to 10 h after dosing with sumatriptan and blood samples were taken up to 26 h post-dose. 3 Propranolol had no significant effect on any of the derived pharmacokinetic parameters of sumatriptan. The appropriate average parameter values in the presence of propranolol were, respectively: C(max) (120 ng ml-1 vs 126 ng ml-1), t(max) (4.5 h vs 3.0 h), AUC (580 ng ml-1 h vs 566 ng ml-1 h), t1/2,z (1.9 h vs 1.8 h). 4 Propranolol had no significant effect on the pharmacodynamics of sumatriptan, as measured by pulse rate and blood pressure. 5 The results of this study would suggest that no alteration in the sumatriptan dosage will be necessary for migraine patients taking propranolol prophylactic therapy.