Thursday, May 10, 2012

Butterbur and Seasonal Allergies

Most NDs and other health professionals familiar with natural products think of Butterbur in relation to migraine headaches, but a colleague of mine recently told me that there was surprisingly strong evidence for butterbur in regards to seasonal allergies. Of course we’re still in the midst of an allergy season that seems like it will never end, so I thought I’d mention this here. I’ve done a number of articles on the topic of allergies and am adding this one to the list.

So of course, there are a variety of recommendations I make during allergy season, including quercetin, vitamin C, bromelain, and probiotics, not to mention eating plenty of veggies, drinking water, and getting exercise. Sometimes, however, even this can be too little to tame seasonal allergies, and even more interventions are needed. Allegra and Claritin are well known OTC treatments for allergies, but I regularly see patients who don’t want to take these medications, either because they are seeking a more natural treatment, or because they suffer side effects when they take them. So what options are out there?

A 2002 study found that a specific extract of butterbur, known generically at ZE 339, but marketed in the US as Petadolex, is as effective as cetirizine (Zyrtec) in alleviating seasonal allergic rhinitis. This was a reasonably large, randomized study. It wasn’t placebo-controlled, as it was designed to establish equivalence of ZE 339 to cetirizine, not superiority of the product to placebo. This is a unique place to ‘jump in’, so to speak, and later studies were left to establish superiority to placebo retrospectively, if you will.

The first study to do so was performed in 2004, a study which compared the butterbur extract to fexofenadine (Allegra) and a placebo, to add another layer of evidence. The study found that butterbur was superior to placebo (as we would have expected), and was as effective as fexofenadine in alleviating nasal symptoms, as well as physiologic measures of allergic response. The study was smaller than the previous one, but again, adds evidence. An additional study of 186 patients, which compared ZE 339 to placebo, but with no comparison to drugs, found that it was indeed superior to placebo, and that higher doses of the herbal extract produced better results.

A 2005 study, the largest of these three studies, included 330 patients, and assessed ZE 339’s effectiveness compared to placebo and fexofenadine. The extract was found to be superior to placebo, and showed a trend towards being as effective as fexofenadine, though this finding was not statistically significant. This result was perhaps a bit disappointing, in that the comparison to the drug was not statistically significant, but nonetheless, the superiority to placebo is still important evidence.

Taken together, these provide fairly strong evidence that this natural product should be considered as a potential treatment for seasonal allergies. However, it is not without potential side effects – in some ways, Petadolex straddles the line between herb and drug, and should be used only under the supervision of a licensed health professional. I often find that many patients and practitioners expect herbs to be entirely free of side effects, and while many herbs are very safe and what side effects they do have are limited, that’s not universally true. Petadolex is generally very well tolerated with few side effects, but there are some potential side effects that practitioners would have to screen for. The take home message for patients is that if you’re interested in treating your allergies naturally, talk to a practitioner. If you’re a practitioner, consider that Petadolex has a proven track record of efficacy, but be aware of safety guidelines for butterbur generally and Petadolex specifically.