Cimetidine Therapy For Verrucae Vulgaris, and Levimasole In Combination With Cimetidine For the Treatment of Verruca Vulgaris
Cimetidine Therapy For Verrucae Vulgaris
Common warts, or verrucae vulgaris, are benign proliferations of the skin and mucosa secondary to the human papillomavirus. There is no specific antiviral therapy for common warts. Instead, there are various treatment modalities, which seek to damage or induce immune destruction of the virus. These treatments include local destructive therapy, topical intra-lesional cytotoxic therapy, topical immunomodulators, and systemic immunomodulators. Treatment decisions are based on the patient’s age, site, size, number, type of warts, immune status, and desire for therapy. Cimetidine, an H2 receptor antagonist, has been shown at high doses (30 to 40 mg/kg per day) to inhibit suppressor T-cell function and augment delayed-type hypersensitivity reactions. Several studies have looked at whether cimetidine would be an effective therapy for warts. In one study,1 20 adult patients (aged 21 to 63 years) with recalcitrant warts were given cimetidine 30 to 40 mg/kg per day orally over 3 doses for 3 months. These patients had warts that had been present for at least 2 years and failed 2 previous therapies. No topical therapies were allowed. Twelve patients (67%) had complete resolution of their warts, while three patients (17%) had more than a 50% reduction in size or number of lesions. No response was seen in 2 patients. Regression of the warts was first seen around 6 to 8 weeks after treatment onset. No relapse was seen in patients with complete regression at both 6 month and 1 year follow-ups. No lab abnormalities or adverse effects were observed. Based on this study, cimetidine appeared to show some efficacy in the treatment of recalcitrant warts. However, a major limitation was the lack of a control group to compare placebo response rates.
In another study,2 70 patients with 5 to 100 or more common warts were randomly assigned to cimetidine 25-40 mg/kg daily or placebo cohorts. Participants received 3 to 4 doses over 3 months. No concurrent topical or systemic medications were allowed. Of note, pregnant and lactating patients, as well as those with liver or kidney disease, were excluded. Complete cure was seen in 32% (9 of 28) of patients in the cimetidine group and 30.7% (8 of 26) of patients in the placebo group. Among patients younger than 16 years of age, more patients (53.3%) had complete clearance in the placebo group compared with the cimetidine group (52.9%). Based on this study, cimetidine was no more effective than placebo in clearing common warts. The authors did note that placebo treatments have been previously shown to have cure rates of 10% to 35% and are more effective than no treatment.
1. Glass AT, Solomon BA. Cimetidine therapy for recalcitrant warts in adults. Arch Dermatol. 1996;132:680-682.
2. Yilmaz E, Alpsoy E, Basaran E. Cimetidine therapy for warts: A placebo-controlled, double-blind study. J Am Acad Dermatol. 1996;34:1005-7.
Levimasole In Combination With Cimetidine For the Treatment of Verruca Vulgaris
Levimasole, a nicotinic acetylcholine receptor agonist, was originally used to treat helminth infections. It has shown immunomodulatory effects including restoration of phagocyte function and enhancement of delayed hypersensitivity to T-cell mediated immunity. Serious side effects include agranulocytosis and cutaneous necrosis. In a study in Pediatric Dermatology, 44 children with at least 6 warts and 2 prior failed treatments were randomly assigned to 2 treatment cohorts: cimetidine 30 mg/kg per day orally divided into 3 doses plus placebo or cimetidine 30 mg/kg per day plus oral levamisole at 2.5 mg/kg on 2 consecutive days per week for a total of 12 weeks. White blood cell counts were monitored at 2-week intervals. Only 31.5% (6) of patients taking cimetidine alone showed complete regression of warts compared to 65% (13) of patients taking combination therapy of cimetidine and levamisole. No response was seen in 52.6% (10) of patients in the cimetidine only group while 20% (4) of patients in the combination therapy were non-responders. It took about 8 weeks for the warts to regress in the combination therapy group, and 11 weeks in the cimetidine only group. There were no side effects in the cimetidine group. Two patients experienced nausea in the combination group with levamisole, with 1 patient having to withdraw due to the severity. No white blood cell abnormalities were noted during treatment. While side effects in this study were limited, known reported side effects of levamisole is a major deterrent to prescribing this combination regimen.
Parsad D, Pandhi R, Juneja A, Negi KS. Cimetidine and levamisole versus cimetidine alone for recalcitrant warts in children. Pediatric Dermatology. 2001;18(4):349-352.