Dose-response curve for the ergotamine-induced decrease of peripheral systolic blood pressure in man.

Ergotamine tartrate (approximately 0.05, 0.125, 0.25 and 0.5 mg per 70 kg body weight) was given intravenously to 5 volunteers in a double-blind cross-over study. For 6 hours the following parameter were studied: arm, ankle and big toe systolic blood pressures. A dose-dependent but transient increase of arm systolic blood pressure was found. For changes of ankle-arm systolic gradients no dose-response curve could be established. Toe-arm systolic gradients showed a dose-dependent decrease, which at 4 to 6 hours seems suitable for pharmacodynamic comparison of different doses or routes of administration of ergotamine tartrate.