About Tolnaftate Thiocarbamate derivative, Antifungal. Mechanism of Action of Tolnaftate Tolnaftate is a reversible noncompetitive inhibitor of Squalene epoxidase enzyme of fungi. This epoxidase enzyme is useful for the conversion of Squalene to sterols. Inhibition of Squalene epoxidase enzyme will leads to a deficiency of sterols (ergosterol) and distort the hyphae and to stunt mycelial growth in susceptible organisms. Indications for Tolnaftate 1. Dermatophytosis 2. Tinea corporis (ringworm of the body) 3. Tinea cruris (ringworm of the groin- jock itch) 4. Tinea pedis (ringworm of the foot- athlete`s foot) 5. Tinea versicolor 6. Tinea barbae