Olopatadine hydrochloride inhibits capsaicin-induced flare response in humans.

ABSTRACT

Capsaicin, a vanilloid, has the potential for releasing substance P (SP) from sensory nerves. Topical application of capsaicin induces a flare response in the skin. However, it has not been clarified whether the release of SP is involved in the process of flare response or not. A potent antihistamine drug, olopatadine hydrochloride, is known to have inhibitory action against the release of SP. We examined the effects of olopatadine (at a dose of 5 mg) on skin reaction induced by topical application of capsaicin in 10 healthy subjects. The scores of capsaicin-induced flare responses after olopatadine administration were significantly lower at 30 min than at baseline. Our findings suggest that olopatadine hydrochloride could inhibit capsaicin-induced flare responses.