Pharmacokinetics of dihydroergotamine in healthy volunteers and in neurological patients after a single intravenous injection.

The pharmacokinetics of dihydroergotamine (DHE) was studied in healthy volunteers (n = 6) and in neurological patients (n = 12). After a single 1.0 mg intravenous injection (n = 5) DHE quickly disappeared (T 1/2 beta = 32.9 min, Vdss = 0.33 liter/kg, Cltot = 1055.7 ml/min). In saliva (dose 1.0 mg, n =6) and cerebrospinal fluid (dose 0.5 mg, n =12) there were no measurable amounts of DHE after a single i.v. dose. The 32-h cumulative urinary excretion was 0.02-0.04% of the 1.0 mg intravenous dose. In one subject renal (0.18 ml/min) and extrarenal (692.9 ml/min) clearance of DHE was calculated. According to our results DHe is probably eliminated mainly by hepatic metabolism. The pharmacokinetic properties of DHE indicate a fast clinical response without a cumulative action.