Topical iontophoretic administration of acyclovir for the episodic treatment of herpes labialis: a randomized, double-blind, placebo-controlled, clinic-initiated trial.
BACKGROUND
Multiple studies of the use of acyclovir for the treatment of herpes labialis have suggested that the nominal efficacy of the topical formulation is the result of inadequate penetration of the drug into the target site of infection, the basal epidermis.


METHODS
We developed a low-voltage, wireless, hand-held, computer-controlled, iontophoretic applicator to enhance the skin penetration of topical acyclovir in the treatment of herpes labialis. We performed a multicenter, placebo-controlled, clinic-initiated, pilot trial of a single, topical, iontophoretic application of 5% acyclovir cream for the episodic treatment of herpes labialis among 200 patients with an incipient cold sore outbreak at the erythema or papular/edema lesion stage.


RESULTS
The median classic lesion healing time (aborted lesions were assigned a value of 0 h) was 1.5 days shorter for the active treatment group than for the vehicle group (113 h vs. 148 h; P = .02). In the subgroup of patients who presented with lesions in the erythema stage, the median classic lesion healing time was 3 days shorter for the acyclovir group, compared with the control group (49 h vs. 120 h; P < .03), and the acyclovir group tended to have more aborted lesions than did the control group (46% vs. 24%; P = .10).


CONCLUSIONS
Single-dose topical iontophoresis of acyclovir appears to be a convenient and effective treatment for cold sores and merits further clinical investigation.
Morrel
Eric M
EM
Transport Pharmaceuticals, Framingham, Massachusetts 01701, USA.
Spruance
Spotswood L
SL
Goldberg
Dennis I
DI
D000212:Acyclovir / Q000008:administration & dosage*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000998:Antiviral Agents / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006560:Herpes Labialis / Q000188:drug therapy*; D006801:Humans; D007478:Iontophoresis; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D016896:Treatment Outcome
D000998:Antiviral Agents; D000212:Acyclovir