Acute Treatment of Migraine Attacks: Efficacy and Safety of A Nonsteroidal Anti-Inflammatory Drug, Diclofenac-Potassium, in Comparison To Oral Sumatriptan and Placebo

BACKGROUND: Migraine attacks are often treated with simple analgesics or with ergotamine-containing preparations alone or in combination with anti-emetics. Although also sometimes used to treat migraine, nonsteroidal anti-inflammatory drugs (NSAIDs) have not been systematically evaluated in controlled clinical trials, particularly in comparison with the newer drug sumatriptan. Sumatriptan is a specific migraine treatment which has recently become among the most widely prescribed acute migraine therapies. However, while effective, it has low oral bioavailability and some problematic adverse effects. Diclofenac-potassium is a potent NSAID available as a fast-acting oral tablet, which has been shown to be safe and effective in several other acute pain indications. In the clinical trial reported here, the efficacy and safety of diclofenac-potassium in the acute treatment of migraine attacks has been tested in comparison with oral sumatriptan and placebo. METHODS: Single oral doses of 50 mg and 100 mg diclofenac-potassium were compared to a single oral dose of 100 mg sumatriptan and placebo in a double-blind randomized crossover trial in 156 adult patients suffering from migraine attacks, with or without aura, selected according to the International Headache Society diagnostic criteria. The primary efficacy criterion was migraine headache pain recorded on a visual analog scale at 2 h after dosing. Secondary endpoints included pain at other time points up to 8 h and the presence of accompanying symptoms (nausea, vomiting, photophobia, phonophobia). FINDINGS: Diclofenac-potassium was more effective than placebo in reducing migraine headache pain at 2 h after dosing, which was the primary endpoint. Secondary analyses showed that diclofenac-potassium provided significant pain relief from 60 min after dosing and for all remaining endpoints in the 8-h observation period. Both 50 and 100 mg doses of diclofenac-potassium were similarly effective. A similar effect was shown with sumatriptan; however, significant superiority to placebo was seen only from the 90-min time point. Diclofenac-potassium was generally superior to placebo or sumatriptan in reducing accompanying symptoms, particularly nausea. Diclofenac-potassium seemed to be as well tolerated as placebo, with fewer adverse events reported than after sumatriptan treatment and with more patients assessing the overall tolerability of diclofenac-potassium better than that of sumatriptan. INTERPRETATION: Compared with placebo and the reference therapy sumatriptan, diclofenac-potassium is an effective, fast-acting, and well-tolerated acute oral therapy for migraine attacks, with advantages over oral sumatriptan in terms of onset of analgesic effect, reduction of accompanying symptoms, and tolerability profile. It may therefore be useful as an alternative oral therapy for migraine attacks.