The Evidence for Herbal and Botanical Remedies, Part 1
While herbal supplements are popular among patients, few are supported by scientific evidence. A review of the literature suggests a few that are worth recommending.
Adverse effects
While the butterbur plant itself contains pyrrolizidine alkaloids (PA), which are hepatotoxic and carcinogenic, extracts of butterbur root that are almost completely free from these alkaloids are available. Patients who choose to use butterbur should be advised to use only products that are certified and labeled PA free.
Petadolex, the medication used in migraine studies, was initially approved by the German health regulatory authority, but approval was later withdrawn due to concerns about liver toxicity.22 In 2012, the United Kingdom’s Medicines and Health Care Products Regulatory Agency withdrew all butterbur products from the market due to associated cases of liver toxicity.22 Butterbur products are still available in the US market, and the risks and benefits should be discussed with all patients considering this treatment. Liver function monitoring is recommended for all patients using butterbur.22
The herb can also cause dyspepsia, headache, itchy eyes, gastrointestinal symptoms, asthma, fatigue, and drowsiness. Additionally, people who are allergic to ragweed and daisies may have allergic reactions to butterbur. Eructation (belching) occurred in 7% of patients in a pediatric study.17
The bottom line
Butterbur appears to be efficacious for migraine prophylaxis, but long-term safety is unknown and serious concerns exist for liver toxicity.
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