Propranolol plasma levels and relief of migraine. Relationship between plasma propranolol and 4-hydroxypropranolol concentrations and clinical effects.

The relationship between propranolol and 4-hydroxypropranolol plasma concentrations and relief of migraine was assessed in 17 patients during treatment with oral racemic propranolol hydrochloride in doses of 40 to 240 mg/day. Propranolol decreased the migraine index more than 70% in 13 patients: five patients at a dosage of 40 mg/day, five patients at a dosage of 120 mg/day, and three patients at a dosage of 240 mg/day. Three patients did not achieve a good improvement of migraine at any of the doses used. The relief of migraine was not directly related to the propranolol and 4-hydroxypropranolol plasma concentrations.