Solution, 10-25%

General information

Podophyllum resin is a powdered mixture of resins extracted from the roots of Podophyllum pelltatum. A solution is prepared by forming a paste with benzoin in alcohol. It is a caustic keratolytic agent for topical application.

Clinical information

Uses

Topical treatment of genital warts (condylomata acuminata).

Dosage and administration

Adults and children: a 10-25% solution should be applied to the affected area. Care must be taken to avoid contact with normal tissue. Zinc oxide paste may be used to protect the surrounding skin. The residue on the skin should be thoroughly rinsed off after 1-4 hours.

Treatment may be repeated at weekly intervals up to a maximum of four applications.

The active ingredient podophyllotoxin (0.5%) is available in some countries. It is less corrosive and can be applied without medical supervision.

Contraindications

Podophyllum resin should not be applied to large areas of skin, nor should it be used in the treatment of cervical, urethral, anorectal or oral warts.

Treatment is contraindicated during pregnancy since podophyllum resin is both teratogenic and fetotoxic.

Precautions

Preparations of podophyllum resin should be used only under close medical supervision because potentially serious local and systemic toxic effects can result from prolonged or excessive applications. Systemic absorption is enhanced when applications are made to friable, bleeding warts.

Adverse effects

The systemic effects of excessive cutaneous absorption include nausea, vomiting, abdominal pain and diarrhoea.

Transient leukopenia and thrombocytopenia sometimes occur, providing evidence of bone-marrow depression.

Gross over-application can result in serious neurotoxicity. The signs are characteristically delayed in onset and slow to resolve. They include visual and auditory hallucinations, delusions, disorientation, confusion and delirium.

Storage

Topical solution should be kept in tightly closed containers, protected from light and excessive heat. The shelf-life of the resin is highly variable and some formulations may begin to degrade within a few days of exposure to light, air or heat.