Plethysmographic comparison of sublingual and intramuscular ergotamine.

The peripheral vasoconstrictive effects of ergotamine, 0.25 mg intramuscularly and 2 mg sublingually, and a sublingual placebo were compared plethysmographically in 12 normal subjects. Both forms of ergotamine induced greater reductions than placebo in venous occlusion blood flow, systolic early ejection rate, systolic midtemporal ejection rate, systolic late runoff rate before aortic valve closure, diastolic runoff rate after aortic valve closure, and maximum and secondary pulse amplitudes. There were no significant differences between the ergotamine forms. The results indicate that the peripheral vasoconstrictive effects of ergotamine are equal after 0.25 mg intramuscularly and 2 mg sublingually. The two forms at those doses should be equally effective in migraine.