PODOPHILLIN 15%

Indications

• Anogenital warts (condylomata acuminata)
• External genital warts

Dosage

Children: Refer to the BNF for Children for specific dosing guidelines.

Adults: Apply twice daily for 3 consecutive days. Treatment may be repeated at weekly intervals if necessary for a total of four 3-day treatment courses, not exceeding the maximum treatment period even if new warts develop.

Mechanism of action

The exact mechanism of action of podophyllotoxin is not fully understood. However, it is believed to bind and inhibit topoisomerase II during the late S and early G2 phases of the cell cycle, stabilizing the temporary breaks caused by the enzyme. This disruption prevents DNA unwinding and replication, effectively stopping cell division and leading to necrosis of the affected tissues.

Pharmacodynamics

Podophyllotoxin is a more stable and purer derivative of podophyllin, containing only the biologically active portion of the compound. It acts primarily by inhibiting mitosis in keratinocytes, which are the predominant cell type in the outermost layer of skin. Its application leads to the destruction of abnormal cells, specifically those involved in wart formation.

Pharmacokinetics

Podophyllotoxin is applied topically, and its systemic absorption is minimal. The drug's effects are localized to the application site, where it exerts its action. The pharmacokinetics of the drug indicate that significant absorption does not typically occur, reducing the risk of systemic side effects. However, caution is advised in patients with hepatic or renal impairment.

Adverse effects

• Balanoposthitis
• Increased risk of infection
• Necrosis
• Painful sexual intercourse
• Phimosis
• Skin reactions
• Urinary disorders
• Urinary tract stenosis
• Vaginal discharge

Interactions

• Catephen may weaken condoms and vaginal diaphragms, alternative methods of contraception should be considered

Precautions

• Avoid broken skin
• Avoid contact with eyes, lips, mouth, and nostrils
• Avoid inflamed skin
• Use under direct medical supervision for lesions greater than 4 cm2
• Caution in patients with renal impairment
• Avoid use in patients with hepatic impairment

Pregnancy

Podophyllotoxin is not recommended during pregnancy due to potential risks to the fetus.

Breast-feeding

Caution is advised when using podophyllotoxin while breastfeeding; consult a healthcare provider.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Ointment 0.5% (Condylomata acuminata treatment)
• Liquid formulation for topical application

Mechanism of action

The exact mechanism of action is not well understood. It does appear, however, that it and its derivatives may bind and inhibit topoisomerase II during the late S and early G2 stage. The drug may bind and stabilize the temporary break caused by the enzyme. This disrupts the reparation of the break through which the double-stranded DNA passes, and consequently stops DNA unwinding and replication The exact mechanism of action for podofilox is unknown. Podofilox is a potent mitotoxic agent that inhibits cell mitosis; cell division stops, other cellular processes are impaired, necrosis occurs, and the affected tissues gradually erode.

Pharmacodynamics

Podofilox, also called podophyllotoxin, is a purer and more stable form of podophyllin in which only the biologically active portion of the compound is present. Podofilox is used to remove certain types of warts on the outside skin of the genital areas.