EXODERIL

Indications

• Tinea pedis (athlete's foot)
• Tinea cruris (jock itch)
• Tinea corporis (ringworm)
• Superficial candidiasis

Dosage

Children: Refer to the BNF for Children for appropriate paediatric dosing guidelines.

Adults: The recommended adult dosage for topical naftifine is to apply the cream to the affected area once daily for 2 to 4 weeks, depending on the condition being treated.

Mechanism of action

Naftifine appears to interfere with sterol biosynthesis by inhibiting the enzyme squalene 2,3-epoxidase. This inhibition leads to decreased levels of sterols, particularly ergosterol, within fungal cells, accompanied by an accumulation of squalene, ultimately disrupting fungal cell membrane integrity and function.

Pharmacodynamics

Naftifine is a broad-spectrum antifungal agent that exhibits fungicidal activity against a variety of dermatophytes such as Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum. It also shows fungistatic activity against Candida species, including Candida albicans. The clinical significance of its in vitro activity is not fully established, but it is effective against specific fungal infections as indicated.

Pharmacokinetics

The pharmacokinetics of naftifine involve topical application, leading to localized action at the site of infection. Systemic absorption occurs but is minimal due to its formulation, which limits systemic exposure. The drug is metabolized in the liver, and excretion primarily occurs via the feces. Detailed pharmacokinetic parameters such as half-life and bioavailability are not extensively documented.

Adverse effects

• Local irritation
• Burning sensation
• Erythema
• Pruritus
• Dryness of the skin

Precautions

• Use with caution in patients with a known hypersensitivity to naftifine or any component of the formulation.
• Avoid contact with eyes and mucous membranes.

Pregnancy

Naftifine should be used during pregnancy only if clearly needed, as there are no adequate and well-controlled studies in pregnant women.

Breast-feeding

It is not known whether naftifine is excreted in human milk. Caution should be exercised when administering to nursing mothers.

Storage

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

Formulations

• Cream
• Gel
• Spray

Mechanism of action

Although the exact mechanism of action against fungi is not known, naftifine appears to interfere with sterol biosynthesis by inhibiting the enzyme squalene 2,3-epoxidase. This inhibition of enzyme activity results in decreased amounts of sterols, especially ergosterol, and a corresponding accumulation of squalene in the cells.

Pharmacodynamics

Naftifine is a synthetic, broad spectrum, antifungal agent and allylamine derivative. The following in vitro data are available, but their clinical significance is unknown. Naftifine has been shown to exhibit fungicidal activity in vitro against a broad spectrum of organisms including <i>Trichophyton rubrum</i>, <i>Trichophyton mentagrophytes</i>, <i>Trichophyton tonsurans</i>, <i>Epidermophyton floccosum</i>, and <i>Microsporum canis</i>, <i>Microsporum audouini</i>, and <i>Microsporum gypseum</i>; and fungistatic activity against <i>Candida</i> species including <i>Candida albicans</i>. However it is only used to treat the organisms listed in the indications.