Intramuscular absorption of dihydroergotamine in man.

In order to prevent hypotension, 1.0 mg of dihydroergotamine (Vasogin) was injected intramuscularly to 10 patients 5 minutes before spinal anaesthesia. The peak plasma concentrations were measured by a radioimmunoassay as early as at 30 minutes after drug administration, indicating a fast intramuscular absorption. According to the plasma levels the drug has to be given 15-30 minutes before spinal anaesthia.