Ergotamine toxicity and serum concentrations of ergotamine in migraine patients.

Twenty-five migraine patients (9 males and 16 females) aged 22-71 who had used between 7 and 60 mg ergotamine tartrate per week for 1.5-30 y volunteered to participate in the study. Side-effects attributable to ergotamine were wide ranging and included daily headache and pain in the limbs. Wide variation in sensitivity to the drug was observed and side-effects were not always proportional to the dose of ergotamine. Random serum ergotamine concentrations were estimated in all patients and 10 of them volunteered to take a 2 mg oral challenge of ergotamine tartrate. Ergotamine was not detected in 44% of the random estimations even though all patients exhibited clinical signs of ergotamine tartrate overdose. The remaining 56% estimations all showed low drug concentrations. After the 2 mg oral challenge of ergotamine in the 10 patients, significantly higher concentrations, but still within therapeutic range, were detected in the sera when compared with mean concentrations achieved after the same oral dose of the drug in healthy, non-migrainous subjects.