Why is a patient taking cimetidine for warts?
You are entering dermatology prescriptions for your patient, IM, from the electronic prescribing queue. After entering several topical medications, you notice the dermatologist has prescribed cimetidine for warts. Is this a mistake?
Mystery: Why is a dermatologist prescribing cimetidine for warts?
Solution: Cimetidine (Tagamet) is an H2 antagonist, like ranitidine (Zantac) and famotidine (Pepcid). Cimetidine is indicated for treatment of duodenal ulcers, GERD, and hypersecretory conditions, such as Zollinger-Ellison syndrome.1
Although data seems inconclusive, and recent large studies have not been published, cimetidine has been used for many years as an off-label treatment of warts. In a 3-month study, treatment with cimetidine resulted in improvement in 87% of children, and in 68% of adults.2
In following up, warts were shown to have recurred in patients who had stopped cimetidine treatment before the warts had resolved. In about 2/3 of patients whose warts had previously cleared, there was no recurrence. The authors found cimetidine to be helpful in the treatment of viral warts in adults and children.2
Another double-blind, placebo-controlled study found cimetidine not to be significantly more effective than placebo, but saw a trend toward efficacy in younger patients.3
A small, retrospective 2018 study4 looked at pediatric heart transplant patients that had previously been treated with high-dose cimetidine (30 mg/kg/day in two divided doses, for 3-6 months). The mechanism of cimetidine in wart treatment is activation of Th1 cells to produce interleukin (IL)-2, IL-12, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, thus improving cellular immunity and wart remission. The authors concluded that cimetidine was a safe, alternative treatment for patients with multiple warts, noting that other treatments are expensive, painful, and can cause scarring.4