Migraine research methods
CMAJ 1997;157:1015
See response from: M.J. Gawel & W.E.M. Pryse-Phillips
Although Dr. William E.M. Pryse-Phillips and associates are to be commended for publishing the first formal guidelines for treatment of migraine ("Guidelines for the diagnosis and management of migraine in clinical practice," CMAJ 1997;156:1273-87 [full text / résumé]), I take issue with some of the recommendations.
Severe and ultra-severe migraine attacks, as well as many moderate migraine attacks, are treated in emergency departments by emergency physicians rather than by neurologists. Therefore, it is disappointing and somewhat inappropriate that none of the authors was an emergency physician. However, I recognize the name of 1 emergency physician with a significant interest in migraine on the consensus panel. Emergency physicians across Canada are developing interest in and experience with the treatment of migraine, as was evident at a recent symposium at the Canadian Association of Emergency Physicians annual scientific meeting.
In most migraine studies, other than those involving sumatriptan, the methods are quite variable and the design is often very poor, with small numbers of patients enrolled. This makes it very difficult to interpret and compare the literature and to make firm recommendations. For intranasal butorphanol, in 1 study cited in the article the 1-hour efficacy rate was only 47%, when placebo rates usually approach 35%.1 This study also listed prominent side effects, which make this therapy less than ideal. The other study cited involved intramuscular administration of butorphanol, in an unblinded fashion, without a placebo control group.2 With respect to chlorpromazine, the recommendation includes a dose of 50 mg given intramuscularly, although the only cited article refers solely to the intravenous dose.3 In a different study of chlorpromazine
(1 mg/kg, given intramuscularly), which included only patients with aura (the minority of migraine sufferers), approximately 20% of patients experienced significant orthostatic hypotension.4 In fact, orthostatic hypotension is a well-known and common side effect of chlorpromazine, although this was not mentioned in the trial by Lane, McLellan and Baggoley cited in the article.3 With respect to dexamethasone, the class of recommendation is really fair to poor. With respect to ketorolac, the evidence supporting its effectiveness in moderate migraine is stronger than the evidence concerning severe and ultra-severe migraine, and the side effects (nausea and dyspepsia) are far more common with the oral form than with the intravenous or intramuscular forms. With respect to meperidine, the doses should be given as milligrams per kilogram. For severe and ultra-severe attacks, doses are more appropriately titrated intravenously to achieve pain relief. Although addiction is a feared effect, a study by Langemark and Olesen5 showed that the risk of dependence on narcotics secondary to treatment of migraine is 1.3 per 100 000 population. A more realistic fear is that a physician may be taken in by a drug-seeker claiming to have migraine.
The article did not mention a case series involving the use of haloperidol. Given intravenously, haloperidol therapy resulted in a 100% response rate and a decrease in pain scores from 8.4 to 1.0, on average.6
It should have been clarified that use of lidocaine intranasally has only a 50% efficacy rate.7
I hope that these guidelines are just a beginning and a basis for discussion and further refinement, particularly with respect to treatment of the most problematic cases, which are the ones we see in the emergency department.
Harold Fisher, MD
Emergency Department
Mount Sinai Hospital
Assistant Professor
Department of Family and Community Medicine
University of Toronto
Toronto, Ont.
References
- Elenbaas RM, Iacono CU, Koelner KJ, et al. Dose effectiveness and safety of butorphanol in acute migraine headache. Pharmacotherapy 1991;11(1):56-63.
- Holfert MJ, Couch JR, Diamond S, et al. Transnasal butorphanol in the treatment of acute migraine. Headache 1995;35:65-9.
- Lane PL, McLellan BA, Baggoley CJ. Comparative efficacy of chlorpromazine and meperidine with dimenhydrinate in migraine headache. Ann Emerg Med 1989;18(4):360-5.
- Iserson KV. Parenteral chlorpromazine treatment of migraine. Ann Emerg Med 1983;12(12):756-8.
- Langemark M, Olesen J. Drug abuse in migraine patients. Pain 1984;19:81-6.
- Fisher H. A new approach to emergency department therapy of migraine headache with intravenous haloperidol: a case series. J Emerg Med 1995;13(1):119-22.
- Maizels M, Scott B, Cohen W, Chen W. Intranasal lidocaine for treatment of migraine. JAMA 1996;276(4):319-21.
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