External therapy with Cannabinoids Effective in Reducing Pain in Patients with Herpes Zoster

BERLIN – Researchers at the Clinic for Skin Diseases at the University of Muenster, Germany, investigated the efficacy of an external treatment of chronic pain caused by herpes zoster with a cannabinoid that activates cannabinoid receptors. In an open-label trial, 8 patients with facial neuralgia in herpes zoster received a cream containing the endocannabinoid palmitoylethanolamine. The course of symptoms was scored with a visual analogue scale.

Five of 8 patients (62.5 per cent) experienced a mean pain reduction of 88 per cent. The therapy was well tolerated by all patients. No unpleasant sensations or adverse events occurred. The authors concluded that “topical cannabinoid receptor agonists are an effective and well-tolerated adjuvant therapy option in postherpetic neuralgia.” This cream is already on the market in Germany under the trade name “Physiogel A.I. Crème” used to treat pruritus.

(Source: Phan NQ, Siepmann D, Gralow I, Ständer S. Adjuvant topical therapy with a cannabinoid receptor agonist in facial postherpetic neuralgia. J Dtsch Dermatol Ges. 2009 Sep 10. [Electronic publication ahead of print])