What is the proper application and dosage of topical cidofovir for treating warts?

From the Guidelines

Topical cidofovir should be applied at a concentration of 1% as a cream, daily for 5 days each week under occlusion for 8 weeks, as recommended by the British Association of Dermatologists' guidelines for the management of cutaneous warts 2014 1. The application of topical cidofovir for treating warts involves several key steps to ensure effective treatment and minimize side effects.

Key Considerations

• The medication is usually compounded by a pharmacy into a cream formulation, as there is no commercially available topical cidofovir product specifically for warts.
• Before application, the wart should be gently debrided to remove any thickened skin or debris.
• The surrounding healthy skin should be protected with petroleum jelly to prevent irritation.
• The medication should be applied only to the wart tissue using a cotton-tipped applicator or gloved finger.
• The treated area should then be covered with an occlusive dressing to enhance penetration of the medication.

Mechanism of Action and Side Effects

• Cidofovir works by inhibiting viral DNA polymerase, thereby preventing viral replication in infected cells 1.
• Patients should be monitored for local side effects including pain, erythema, and erosion at the application site.
• It is essential to note that topical cidofovir is generally well-tolerated, with local irritation being the most common side effect, although one patient with a background of chronic renal failure developed acute deterioration in renal function during treatment 1.

Treatment Cycle and Duration

• Treatment cycles may be repeated after a 1-2 week break, with most patients requiring 2-4 cycles for optimal results.
• The British Association of Dermatologists' guidelines recommend a treatment duration of 8 weeks for topical cidofovir 1.

Alternative Treatments

• Other treatments for warts, such as salicylic acid, cryotherapy, and imiquimod, may be considered before or in conjunction with topical cidofovir, depending on the patient's specific needs and medical history 1.

From the Research

Application and Dosage of Topical Cidofovir for Warts

The application and dosage of topical cidofovir for treating warts can vary based on the concentration of the cream and the frequency of application.

• Concentration: The concentration of topical cidofovir used in studies ranges from 1% to 3% 2, 3, 4, 5, 6.
• Frequency of application: The frequency of application also varies, with some studies using twice daily applications 3, 5 and others using every other day to daily applications 4, 6.

Efficacy and Safety

The efficacy and safety of topical cidofovir for treating warts have been assessed in several studies.

• Efficacy: Topical cidofovir has been shown to be effective in treating various types of warts, including plantar warts 3, periungual warts 5, and verrucae in children 4, 6.
• Safety: Common side effects of topical cidofovir include inflammation, erosion, and a burning sensation at the application site 2, as well as postinflammatory hyperpigmentation and transient alopecia in some cases 2.

Specific Treatment Regimens

Some studies have reported specific treatment regimens for topical cidofovir.

• For plantar warts, a 3% concentration applied twice daily has been used 3.
• For periungual warts, a 3% concentration applied twice daily has also been used 5.
• For verrucae in children, concentrations ranging from 1% to 3% have been used, with applications every other day to daily 4, 6.