 |
|
What Counts as Evidence?
A Personal Odyssey Into Alternative Care
Arch Fam Med. 1998;7:598-599.
EARLY ONE morning, while driving to the Family Practice Center, I heard a comment from a medical news report on a local radio station that "peppermint oil is found to be effective for headaches." I caught the tail end of this therapeutic snippet, but was interested by the possibility of a new therapy for this common problem and decided to look into it further. I turned to the resource that many patients are using to learn about medical breakthroughs: the Internet. The study was easily found in MEDLINE's database by searching for the terms tension-type headache and peppermint oil. The Internet provided an English translation of the abstract of the original article, written in German, and our local health sciences library needed several weeks to get a full copy, but I was content to mull over the abstract.
The abstract reported the effect of locally applied peppermint oil on tension-type headaches, as classified by the International Headache Society criteria.1 The study was a randomized, placebo-controlled, double-blind crossover design of 41 patients suffering from 164 headache attacks. A liquid test preparation of 10% peppermint oil in ethanol solution was used and compared with both 1000 mg of acetaminophen (or identical placebo tablet) and placebo (traces of peppermint oil in ethanol solution to produce the same smell). Headache diaries were kept by patients to record their headache severity at 15, 30, 45, and 60 minutes after the intervention. The results showed a significant reduction of pain intensity with 10% peppermint oil compared with placebo at 15 minutes (P<.01). The 1000 mg of acetaminophen was also significantly better at pain relief at 15 minutes when compared with placebo (P<.01). No adverse effects were reported.
This well-designed study was performed by a group of neurologists based at Kiel University School of Medicine in Kiel, Germany, indicating its reliability and quality. I also found an earlier abstract by the same authors who reported that peppermint oil had direct analgesic effects through a neurophysiologic mechanism, and significantly reduced headache sensitivity when applied to the forehead2; however, without the original article describing the randomized, controlled trial, I could not undertake the critical appraisal we use every week at our residency journal club. The simple treatment made me question whether it would be reasonable to change my clinical practice based on the abstract alone, but a safe, cheap, and effective treatment for headaches sounded like a breakthrough for frustrated physicians and patients alike.
I decided to try the peppermint oil on myself. The opportunity arose when after long hours at the clinic and spending the previous night on call, the front of my head felt as though it was clamped in a vice (a classic description of tension-type headache, I think). I stopped at the grocery store on the way home and found a small bottle of peppermint oil in the baking section. It cost $2.17 to buy a peppermint oil similar to that used in the study. When I got home, I unscrewed the bottle and rubbed the oil on my forehead and temples, and within 15 minutes my headache was gone! After using it successfully on several more occasions, I recommended it to some friends for their headaches, and they also reported good responses.
Then one day, I saw a patient with tension-type headaches, who was frustrated with her poor response to our attempts to control her symptoms. I suggested peppermint oil as an option, although I was apprehensive about mentioning alternative medicine. She looked at me skeptically and then was silent. I quickly tried to defend my suggestion by referring to the scientific evidence of the randomized, controlled study, even offering a copy of the abstract she could take home. She was not persuaded until I told her about my experience with the peppermint oil and how well it had worked for my wife. This immediately caught her attention, and she asked in disbelief if it really worked for me. When I confirmed its benefit, she agreed to give it a try. It was apparent that the evidence of this well-controlled study was less important to this patient than a physician's personal testimonial.
Alternative or complementary medicines are becoming more popular. Many medical schools now offer courses to learn about these substances. The Society of Teachers of Family Medicine has a special interest group and has developed a residency curriculum, and the American Association of Medical Colleges has established a study group to help develop complementary medicine educational programs. As primary care physicians, it is important that we continue to educate ourselves on this topic.
Few of these medicines have been evaluated by the Food and Drug Administration to identify their effectiveness, adverse effects, or interactions with other medicines, and there is a shortage of well-done studies examining these products. Most of the research has been done in other countries, where alternative medicine is widely practiced and accepted as part of the health care system. Many of our patients learn about them through books, magazines, television, and the Internet, and will use these therapies despite our reluctance to consider them. We should at least begin to ask all patients as part of our medication review if they are taking any complementary medicines.
As clinicians, we must ask ourselves how much evidence is enough to assist patients with their use of complementary medicines. In the case of peppermint oil, I believe the evidence is enough to offer this treatment. Further randomized, controlled trials are likely to take several years to be published. Peppermint oil was effective in the randomized, controlled trial discussed and in my limited use of the treatment. There are no adverse effects to report from the study or from my use of this topical therapy.
Peppermint oil seems to be a harmless and effective treatment for tension-type headaches. Why not offer this medicine to patients? Can we be comfortable with the limited information about this new and apparently harmless treatment, or do we wait for more randomized, controlled trials? Do we place ourselves at risk if we offer this or other complementary medicines? Peppermint oil has also been reported in the English language literature to be effective in treatment of nonulcer dyspepsia, postoperative nausea, irritable bowel syndrome, and colonic spasm during barium enema.3-6 What about you—does the evidence convince you to try peppermint oil? Or are you, like my patient, persuaded more by the testimonial?
AUTHOR INFORMATION
Special thanks to Peter Curtis, MD, who helped in developing this article.
Corresponding author: Dan Richard, MD, Department of Family Medicine, University of North Carolina-Chapel Hill, 1 Teakwood Ct, Durham, NC 27713, (e-mail: richardd{at}med.unc.edu).
Dan Richard, MD
Chapel Hill, NC
REFERENCES
|
1. Gobel H, Fresenius J, Dworschak M, Soyka D. Effectiveness of oleum menthae piperitae and paracetamol in therapy of headache of the tension type. Nervenarzt. 1996;67:672-681.
FULL TEXT
|
WEB OF SCIENCE
| PUBMED
2. Gobel H, Schmidt G, Soyka D. Effect of peppermint and eucalyptus oil preparations on neurophysiological and experimental algesimetric headache parameters. Cephalgia. 1994;14:228-234.
FULL TEXT
| PUBMED
3. May B, Kuntz HD, Keiser M, Kohler S. Efficacy of a fixed peppermint oil/caraway oil combination in non-ulcer dyspepsia. Arzneimittelforschung. 1996;46:1149-1153.
PUBMED
4. Tate S. Peppermint oil: a treatment for postoperative nausea. J Adv Nurs. 1997;26:543-549.
FULL TEXT
| PUBMED
5. Sparks MJ, O'Sullivan P, Herrington AA, Morcos SK. Does peppermint oil relieve spasm during barium enema? Br J Radiol. 1995;68:841-843.
FREE FULL TEXT
6. Liu JH, Chen GH, Yeh HZ, Huang CK, Poon SK. Enteric-coated peppermint oil capsules in the treatment of irritable bowel syndrome: a prospective, randomized trial. J Gastroenterol. 1997;32:765-768.
WEB OF SCIENCE
| PUBMED
|
