Use of propranolol hydrochloride as prophylaxis for migraine may somehow alter the vasculature so that the headaches diminish in frequency even though propranolol treatment has been stopped.
This preliminary finding comes from what is believed to be the first long-term crossover study of the drug's use in patients with migraine.
In a report to an international migraine symposium that was part of the World Neurology Congress held in Kyoto, Japan, Seymour Diamond, MD, of Chicago, said he found that 35 (46%) of 75 migraine patients who took propranolol for six months or more continued to maintain that improvement for some months following discontinuation of the medication.
Only 11% of the group, he said, "had a rebound-like reaction in that they suffered more headaches following discontinuation than they did during the period before taking propranolol."
The reason for the persistence of such improvement in close to half the group is unknown,