A randomized, double-blind, placebo-controlled study to test the efficacy of topical 2-hydroxypropyl-Beta-cyclodextrin in the prophylaxis of recurrent herpes labialis

Herpes labialis affects one third of the population. We evaluated the topical application of an antiviral compound, hydroxypropyl-β-cyclodextrin (2-HPβCD), in reducing herpes labialis relapses. In this double-blind, randomized, placebo-controlled trial, 40 patients were randomized to a polyethylene glycol (PEG) formulation containing 20% 2-HPβCD or to a vehicle control arm. The gel was applied to the lips twice daily for 6 months. The primary objective was reducing herpes relapses. Surprisingly, the drug group had significantly more relapses than the vehicle group (p = 0.003). While the median numbers of relapses in the preceding year were 12 in the vehicle group and 10 in the drug group, both groups experienced very few relapses during the 6-month treatment period, with a median of 0 in the vehicle group and a median of 2 in the drug group. The impressive reduction of relapses in both groups may be due to a placebo effect or due to the topical treatment with PEG.