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Therapeutics

Metoprolol reduced severity of migraine but had more adverse effects than acupuncture

ACP J Club. 1994 Sept-Oct;121:36. doi:10.7326/ACPJC-1994-121-2-036


Source Citation

Hesse J, Møgelvang B, Simonsen H. Acupuncture versus metoprolol in migraine prophylaxis: a randomized trial of trigger point inactivation. J Intern Med. 1994 May;235:451-6.


Abstract

Objective

To compare the prophylactic effect and side effects of acupuncture (dry needling of trigger points) with metoprolol in patients with migraine.

Design

17-week randomized, triple-blind, controlled trial.

Setting

Pain clinic in Denmark.

Patients

85 patients between 21 and 70 years of age who had had migraines, with or without aura, for ≥ 2 years with 2 to 6 attacks monthly and who were not taking prophylactic drugs responded to a newspaper advertisement or were referred by their general practitioner. Exclusion criteria were other chronic pain syndromes, contraindication to β-blocking agents, previous experience with acupuncture or metoprolol, pregnancy, drug abuse, or disablement pension. Follow-up was 91%.

Intervention

Patients were allowed only symptomatic medication during a 4-week run-in period and were then allocated to receive acupuncture plus placebo tablets (n = 38) or metoprolol, 100 mg daily, plus placebo stimulation (superficial touch from the blunt end of the needle) (n = 39). The therapist determined the nature, interval between, and number of treatments for each patient in the acupuncture group; these variables were chosen at random for patients in the metoprolol group. Compliance was checked by pill count at the end of the study.

Main outcome measures

Patients recorded the frequency and duration of migraine attacks, plus a global rating (1 = mild, 2 = moderate, and 3 = severe) incorporating severity and duration of pain, as well as nausea, vomiting, and other symptoms.

Main results

Both groups had a reduction in headache frequency during the trial compared with the run-in period (P < 0.01). No difference existed between the 2 groups for frequency or duration of migraine attacks, although trends favored metoprolol. A median difference of 0.3 (95% CI 0.1 to 0.5, P < 0.05) in global rating of attacks existed in favor of metoprolol. Fewer patients in the acupuncture group had adverse effects than did those in the metoprolol group { P = 0.031}* (Table).

Conclusion

Metoprolol reduced the severity of migraine attacks but caused more adverse effects when compared with acupuncture in patients with migraine.

Sources of funding: Danish Health Foundation; Sygekassernes Helsefond; Danish Medical Research Council.

For article reprint:Dr. H. Simonsen, Skive Hospital, Department of Rheumatology, DK-7800 Skive Denmark. FAX 45-3268-38581.

* P value calculated from data in article.


Table. Metoprolol vs acupuncture for adverse effects in patients with migraine†

Outcome at 17 wk Metoprolol Acupuncture RRI (95% CI) NNH (CI)
Adverse effects 36% 8% 355% (56 to 1304) 4 (2 to 10)

†Abbreviations defined in Glossary; RRI, NNH, and CI calculated from data in article.


Commentary

Conventional pharmacologic prophylaxis of migraine offers only modest relief with relatively high side-effect liability. As a result, headache is among the conditions for which patients often seek alternative treatment (1). A comparison of standard prophylactic drug treatment for migraine with alternative, nonpharmacologic treatment is therefore of great clinical interest. Standardized diagnostic criteria, adequate randomization, convincing sham treatment, and adequate trial length make the trial by Hesse and colleagues an unusually rigorous study of alternative treatment. Nonetheless, caution should be exercised in applying the results to clinical practice.

Tender craniocervical musculature is often noted in patients with migraine but is not required for diagnosis and is not universally present on examination. Lacking information on how trigger points were identified in this study, the ability of other practitioners to obtain similar results is uncertain. The word "acupuncture" is confusing; in this study the term refers to needling trigger points, although in practice it is often used loosely to describe diverse techniques. Study results cannot be generalized to methods other than dry needling.

The conclusion that metoprolol was superior to trigger point inactivation in decreasing migraine severity is convincing, but the magnitude of the effect is of questionable clinical importance. Selected side effects were significantly more common with metoprolol, but important disadvantages of needling (cost, inconvenience) were not considered. The assertion that metoprolol and dry needling were equally effective in reducing frequency and duration of migraine episodes seems overreaching because the statistical power of this small trial is not reported.

Finally, the clinician doing dry needling necessarily knew whether patients received sham or actual treatments and, presumably, believed actual treatment was superior. This knowledge can bias results in favor of active treatment (2). This trial could be interpreted as showing that an interested clinician, convinced of treatment benefit, is the treatment.

Elizabeth Loder, MD
Spaulding HospitalBoston, Massachusetts, USA


References

1. Eisenberg DM, Kessler RD, Foster C, et al. Unconventional medicine in the United States. Prevalence, costs, and patterns of use. N Engl J Med. 1993;328:246-52.

2. Turner JA, Deyo RA, Loeser JD, Von Knoff M, Fordyce WE. The importance of placebo effects in pain treatment and research. JAMA. 1994;271:1609-14.