What are the guidelines for treating warts with injectable bleomycin (antitumor antibiotic)?

From the Guidelines

Injectable bleomycin is a viable treatment option for recalcitrant warts, particularly for those that have failed conventional therapies, with a recommended concentration of 1 unit/mL and a typical dose ranging from 0.1 to 0.5 mL per wart. The treatment protocol involves injecting bleomycin directly into the wart using a 30-gauge needle, with treatment sessions spaced 3-4 weeks apart, and most patients requiring 1-3 sessions for complete resolution 1. Prior to injection, local anesthesia with lidocaine (with or without epinephrine) is recommended to minimize pain, and the area should be cleaned with alcohol before injection. The needle should be inserted at the junction of the wart and normal skin, with multiple small injections throughout the wart. Some key points to consider when using injectable bleomycin for warts include:

• Potential side effects, such as pain, local necrosis, and Raynaud's phenomenon in acral sites
• Contraindications, including pregnancy, breastfeeding, peripheral vascular disease, and immunosuppression
• Reported success rates of 60-95% depending on wart location and previous treatment history It is essential to weigh the benefits and risks of injectable bleomycin treatment for warts, considering the individual patient's circumstances and medical history, as outlined in the British Association of Dermatologists' guidelines for the management of cutaneous warts 1.

From the FDA Drug Label

ADMINISTRATION: Bleomycin for Injection may be given by the intramuscular, intravenous, subcutaneous, or intrapleural routes. The FDA drug label does not answer the question.

From the Research

Guidelines for Treating Warts with Injectable Bleomycin

• The use of intralesional bleomycin for the treatment of warts has been documented since the 1970s, with cure rates ranging from 14% to 99% 2.
• A double-blind placebo-controlled crossover study found that intralesional bleomycin (1 U/ml) resulted in an 81% cure rate for recalcitrant warts, with lower cure rates for plantar warts (60%) compared to periungual warts (94%) and warts on other extremities (95%) 3.
• Reduced doses of bleomycin (0.25 U/ml and 0.5 U/ml) have also been evaluated, with a study finding that 0.5 U/ml was as effective as 1 U/ml in treating recalcitrant warts 4.
• Intralesional injection of bleomycin (1 mg/ml) every 2 weeks for up to four sessions has been shown to be effective in treating plantar warts, with a cure rate of 69.3% and minimal side effects 5.
• Various methods of bleomycin delivery have been described, including intralesional injection, intralesional injection combined with laser, microneedling, multiple puncture, and adhesive tape, with cure rates ranging from 63.6% to 100% 6.

Administration and Dosage

• Intralesional bleomycin can be administered at concentrations of 0.25 U/ml, 0.5 U/ml, or 1 U/ml, with treatment intervals of 2-3 weeks 3, 4.
• The dosage scheme and techniques for administration of intralesional bleomycin can vary, with some studies using a maximum of four sessions 5.
• Microneedling and multipuncture techniques have been found to be less painful than intralesional injection, with similar efficacy 6.

Efficacy and Safety

• Intralesional bleomycin has been shown to be effective in treating recalcitrant warts, with cure rates ranging from 67.8% to 99.23% 2, 3, 6.
• The treatment is generally well-tolerated, with minimal side effects, including pain, hemorrhagic eschar, and scarring 3, 4, 5.
• Long-term safety of intralesional bleomycin requires further study 3.