Feverfew

Results from clinical trials indicate that dried feverfew ( Tanacetum parthenium ) leaves (not extracts) may be used for the prophylaxis of migraine headaches. Placebo- controlled clinical trials have demonstrated that oral administration of feverfew reduces the frequency and severity of migraine attacks, as well as the degree of nausea and vomiting. Patients should be directed to use dried encapsulated feverfew leaf products and not feverfew leaf extracts, as the extracts (even standardized extracts) are not effective, as shown in clinical trials. The recommended dosage form is an encapsulated fresh or dried leaf preparation, with a daily dose equivalent to 0.2–0.6 mg of parthenolide. Treatment for 1–3 months may be required before the therapeu- tic results are apparent. Administration of feverfew is contraindicated during preg- nancy or nursing, in children under the age of 12 years, and in those patients with an allergy to plants in the daisy family. No drug interactions have been reported in the medical literature. Adverse reactions include dizziness, heartburn, indigestion, inflam- mation of the mouth and tongue, accompanied by swelling of the lips; loss of taste, mouth ulceration; and weight gain. Mouth ulceration, while rare, appears to be due to a systemic reaction and requires discontinuation of feverfew administration.