Diclofenac with or without an antiemetic for acute migraine headaches in adults Stable (no update expected for reasons given in 'What's new')
This review is an update of a previously published review in Issue 2, 2012 (Derry 2012a). Migraine is a common, disabling condition and a burden for the individual, health services and society. Many sufferers choose not to, or are unable to, seek professional help and rely on over‐the‐counter (OTC) analgesics. Diclofenac is an established analgesic, and new formulations using the potassium or epolamine salts, which can be dissolved in water, have been developed for rapid absorption, which may be beneficial in acute migraine. Co‐therapy with an antiemetic should help to reduce the nausea and vomiting commonly associated with migraine.
To determine the efficacy and tolerability of diclofenac, alone or in combination with an antiemetic, compared to placebo and other active interventions in the treatment of acute migraine headaches in adults.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the Oxford Pain Relief Database, ClinicalTrials.gov, and reference lists for studies through 27 September 2011 for the original review and 15 February 2013 for the update.
We included randomised, double‐blind, placebo‐controlled or active‐controlled studies, or both, using self administered diclofenac to treat a migraine headache episode, with at least 10 participants per treatment arm.
Data collection and analysis
Two review authors independently assessed trial quality and extracted data. We used numbers of participants achieving each outcome to calculate relative risk (or 'risk ratio') and numbers needed to treat to benefit (NNT) or harm (NNH) compared to placebo or a different active treatment.
Five studies (1356 participants, 2711 attacks) compared oral diclofenac with placebo, and one also compared it with sumatriptan; none combined diclofenac with a self administered antiemetic. Four studies treated attacks with single doses of medication, and two allowed an optional second dose for inadequate response. Only two studies, with three active treatment arms, provided data for pooled analysis of primary outcomes. For single doses of diclofenac potassium 50 mg versus placebo (two studies), the NNTs were 8.9, 6.2, and 9.5 for pain‐free at two hours, headache relief at two hours, and pain‐free responses at 24 hours, respectively.
Similar numbers of participants experienced adverse events, which were mostly mild and transient, with diclofenac and placebo.
There were insufficient data to evaluate other doses of oral diclofenac, or to compare different formulations or different dosing regimens; only one study compared oral diclofenac with an active comparator (oral sumatriptan 100 mg).
Oral diclofenac potassium 50 mg is an effective treatment for acute migraine, providing relief from pain and associated symptoms, although only a minority of patients experience pain‐free responses. Adverse events are mostly mild and transient and occur at the same rate as with placebo.
Sheena Derry, Roy Rabbie, R Andrew Moore
Plain language summary
Diclofenac with or without an antiemetic for acute migraine headaches in adults
This review found that oral diclofenac potassium 50 mg was an effective treatment for migraine headache, reducing moderate to severe pain to no more than mild pain within two hours in about half (55%) of those treated, to no pain at two hours in about one in five (22%), and to no pain sustained to 24 hours in about the same number (19%). Adverse events were mostly self limiting and of mild or moderate intensity, and were not significantly different from placebo over the short term. Although diclofenac provided good outcomes for some people, almost half did not experience adequate pain relief within two hours, and as few as one in five became pain‐free. It is not clear whether the 100 mg dose provides good outcomes for more people. For those who do not experience adequate responses, a different therapy will be needed.
There was no information about different formulations of diclofenac (e.g. suppositories) to treat acute migraine headaches.
Sheena Derry, Roy Rabbie, R Andrew Moore
Implications for practice
Limited data indicate that diclofenac potassium is an effective treatment for the relief of headache pain in some patients with moderate or severe migraine headache. While the NNTs for headache relief at two hours, pain‐free at two hours and sustained pain‐free during the 24 hours postdose are of borderline clinical utility, the 50 mg dose achieves these three outcomes in 55%, 22%, and 19%, respectively, of patients who treat moderate or severe pain.
Implications for research
Diclofenac is a well‐established analgesic in both acute and chronic pain conditions. It seems unlikely that more clinical trials will be conducted to show that any given formulation is more effective than placebo in migraine, though studies on faster‐acting formulations would be useful. Further head‐to‐head trials would establish its place relative to alternative treatments for migraine and should ideally also include a placebo. Studies investigating different dosing regimens, and combination with an antiemetic, could further establish the optimum dosing regimen for oral diclofenac. All future studies should use IHS‐preferred outcomes to facilitate comparison across studies.Get full text at The Cochrane Library
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