Early and transient side effects of repetitive intravenous dihydroergotamine.

Side effects associated with administration of repetitive intravenous dihydroergotamine (DHE) were prospectively studied in 72 patients with chronic daily headache who were hospitalized in a dedicated inpatient headache treatment program. All patients received 11 consecutive doses of DHE, starting with 0.25 mg and increasing by 0.25 mg up to a maximum dose of 1.25 mg, depending on side effects and/or headache relief. The adverse events were recorded after each dose administered. The great majority of patients (91.6%) reported at least one side effect. The most common were: nausea (72.2%), increase in previous headache (47.2%), lightheadedness (33.3%), "new" headache (27.8%), and leg cramps (23.6%). The overall number of side effect complaints did not increase proportionally with the strength of the dose of DHE administered. These complaints declined from the earlier to the later doses of DHE, except for leg cramps, which were more common with the later doses. Side effects determined the strength of subsequent doses of DHE in only 18.1% of patients. Only four patients had to have a decrease in dosage and none required termination of DHE due to side effects. Although repetitive intravenous DHE causes frequent side effects, they are usually mild and transient and decrease with subsequent doses, even at higher doses.