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Swiss researchers have conducted a new study showing the safety and efficacy of a special extract of butterbur leaf compared to both the conventional pharmaceutical drug fexofenadine and a placebo for treating intermittent allergic rhinitis (IAR), commonly referred to as hayfever.1
In the largest clinical trial to date on butterbur leaf, the randomized, double-blind, placebo- and reference-controlled, three-arm, multi-center trial was based on 330 out-patients in 11 centers in Switzerland and Germany. (A reference-controlled trial compares a medication directly against a medication known to be active, in this case, the antihistamine fexofenadine, serving as an active control.) The trial was conducted according to U.S. Food and Drug Administration Guidance for Industry on clinical trials for allergic rhinitis.
Study medications were a special carbon dioxide extract of butterbur leaf (Ze 339, aka Tesalin®, produced by Max Zeller Söhne AG of Romanshorn, Switzerland) and fexofenadine (Telfast® 180 aka Allegra®, Aventis), a conventional antihistamine drug. Daily dosages used in the trial were 3 tablets of Ze 339 (standardized to 8 mg petasine each) versus one tablet of fexofenadine, or placebo, using a double dummy technique for complete blinding.
The primary measurement was a change in IAR symptoms during the day. These symptoms include sneezing, watery eyes, itching eyes and nose, and nasal congestion. Researchers also measured changes experienced in the evening and at night, based on the physicians’ assessments and the rates of patients’ responses.
The trial results concluded that both the special butterbur leaf extract and the antihistamine drug were equally significantly superior in reducing IAR symptoms than the placebo; i.e., the phytomedicine and the conventional drug showed about equal efficacy. However, the butterbur showed a predictably safer profile as it did not produce the sleepy, drowsy effect that is characteristic of antihistamine medications.
The research team was led by principal investigator Dr. Andreas Schapowal of the Allergy Clinic in Landquart, Switzerland. Dr. Schapowal has previously published clinical trials on Ze 339, showing its efficacy compared to placebo in a dose-ranging trial 2 and another trial favorably comparing it to the conventional pharmaceutical IAR drug, cetirizine (Zyrtec®, Pfizer). 3
Butterbur (Petasites hybridus (L.) P. Gaertn. et al., Asteraceae) is native to Europe. All parts of the plant are known to contain potentially hepatotoxic pyrrolizidine alkaloids (PAs), although the PAs are found in higher concentrations in the root than in the leaves and other aerial parts. Ze 339 is made from specially grown butterbur plants that have been bred to produce a low amount of PAs in the leaves, with the PAs then removed to virtually almost undetectable levels by a special carbon dioxide-based extraction process.
Note: A significantly different butterbur preparation, a standardized extract made from butterbur roots, called Petadolex® (Weber & Weber GmbH & Co, KG, Germany, imported by Weber & Weber International, Windermere, FL) has recently shown potential benefit for treating asthma in a non-controlled observational study 4 as well as evidence for treating migraine headaches in a recently published clinical trials. 5
--Mark Blumenthal
References
1.Schapowal A. Treating Intermittent Allergic Rhinitis: A Prospective, Randomized, Placebo and Antihistamine-controlled Study of Butterbur Extract Ze 339. Phytotherapy Research 2005;19(6):530-537.
2. Schapowal A. Butterbur Ze339 for the treatment of intermittent allergic rhinitis: dose-dependent efficacy in a prospective, randomized, double-blind, placebo-controlled study. Arch Otolaryngol Head Neck Surg. 2004 Dec;130(12):1381-6.
3. Schapowal A. Randomised controlled trial of butterbur and cetirizine for treating seasonal allergic rhinitis. BMJ. 2002 Jan 19;324(7330):144-6.
4. Danesch U. Petasites hybridus (Butterbur root) extract in the treatment of asthma--an open trial. Altern Med Rev. 2004;9(1):54-62.
5. Lipton RB, Gobel H, Einhaupl KM, Wilks K, Mauskop A. Petasites hybridus root (butterbur) is an effective preventive treatment for migraine. Neurology. 2004;63:2240-2244.
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