Danesch U. Petasites hybridus (butterbur root) extract in the treatment of asthma - an open trial Alternative Medicine Review. 2004;9(1):54-62.Asthma is a chronic inflammatory disorder of the airways. Asthma treatment typically consists of a control medication to provide long-term therapy and a relief medication to provide quick-relief therapy. The therapies have the potential to cause adverse systemic side effects. Butterbur (Petasites hybridus) root powder has been shown to improve lung function in patients with chronic asthma and chronic bronchitis (a condition of excessive mucus and cough). The active compound is thought to be petasins, a group of sesquiterpene compounds. The purpose of this study was to assess the efficacy and safety of Petadolex® (Weber & Weber International GmbH & Co. KG, Germany), an extract of butterbur, in patients with asthma.
Eighty patients (aged 6-85 years) with mild or moderate asthma participated. While the article states that the study took place at multiple locations, it does not give information on those locations. The open label study consisted of a two-week run-in phase and a 2-4 month treatment phase (adults: 50 mg Petadolex 3 times/day, children: 50-150 mg daily, depending on age). Patients were permitted to continue with their regular asthma medications. Patients recorded symptoms in a diary and were examined by a physician 4 and 8 weeks after consuming Petadolex.
Lung function tests were performed to assess and monitor airflow obstruction. Approximately two-thirds of the patients had a clinically significant increase in airflow. The results show that compared to baseline there is a decrease in the number, duration, and severity of asthma attacks after treatment. (The authors did not state whether the decreases were statistically or clinically significant.) However, upon closer inspection of the data, the number of patients who had asthma attacks increased compared to baseline. The authors do not discuss this discrepancy. Patients were permitted to continue the treatment with Petadolex if they desired. The results show that the asthma symptoms (coughing, difficulty breathing, chest tightness, wheezing, etc.) continued to improve in patients who continued to take Petadolex. Ninety-five percent of the patients reported that Petadolex was effective in treating their asthma. Of the patients taking pharmaceuticals in addition to Petadolex, 43-48% reduced the amount of pharmaceuticals used while they were consuming Petadolex. However, by week 16, 68% of the patients had voluntarily discontinued taking Petadolex. The authors do not discuss this contradiction.
Petadolex was well tolerated. The authors believe that adverse events reported were probably not related to treatment with Petadolex.
The authors conclude that 150 mg of a butterbur extract is an effective and safe asthma treatment for children and adults. However, this study has several weaknesses. (1) Nearly 80% of the patients had mild asthma. Therefore, the question remains as to whether Petadolex would be effective in patients with moderate or severe asthma. It was not effective in one child who had an exceptionally high number of asthma attacks while attending camp during hay fever season. (2) There are many different triggers for an asthma attack, for example, allergies, smoke, and exercise. The authors did not indicate what the triggers were for this patient population. Perhaps the patients who improved were not exposed to their asthma trigger. (3) There was no control group, so there is no way to know if the improvement may have been due to a placebo effect. The study needs to be repeated with a better design before firm conclusions can be made.
Heather S. Oliff, Ph.D.