indication

For topical application in the treatment of tinea pedis (athlete’s foot), tinea cruris, and tinea corporis caused by Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum, in the treatment of cutaneous candidiasis (moniliasis), and in the treatment of tinea versicolor.

pharmacology

Miconazole is an anti-fungal medication related to fluconazole (Diflucan), ketoconazole (Nizoral), itraconazole (Sporanox), and clotrimazole (Lotrimin, Mycelex). It is used either on the skin or in the vagina for fungal infections. Miconazole was approved by the FDA in 1974. Miconazole prevents fungal organisms from producing vital substances required for growth and function. This medication is effective only for infections caused by fungal organisms. It will not work for bacterial or viral infections.

mechanism of action

Miconazole interacts with 14-α demethylase, a cytochrome P-450 enzyme necessary to convert lanosterol to ergosterol. As ergosterol is an essential component of the fungal cell membrane, inhibition of its synthesis results in increased cellular permeability causing leakage of cellular contents. Miconazole may also inhibit endogenous respiration, interact with membrane phospholipids, inhibit the transformation of yeasts to mycelial forms, inhibit purine uptake, and impair triglyceride and/or phospholipid biosynthesis.

toxicity

Oral, mouse: LD₅₀ = 3800 mg/kg; Oral, rat: LD₅₀ = 3 gm/kg. Ingestion of the amounts of the components contained in a tube of cream are unlikely to produce overdosage and toxic effects.

drug interactions

Acenocoumarol: Miconazole may increase the serum concentration of acenocoumarol by decreasing its metabolism.

Anisindione: Miconazole may increase the serum concentration of anisindione by decreasing its metabolism.

Dicumarol: Miconazole may increase the serum concentration of dicumarol by decreasing its metabolism.

Tacrine: The metabolism of Tacrine, a CYP1A2 substrate, may be reduced by Miconazole, a CYP1A2 inhibitors. Monitor the efficacy and toxicity of Tacrine if Miconazole is initiated, discontinued or if the dose is changed.

Tacrolimus: The strong CYP3A4 inhibitor, Miconazole, may decrease the metabolism and clearance of Tacrolimus, a CYP3A4 substrate. Consider alternate therapy or monitor for changes in therapeutic and adverse effects of Tacrolimus if Miconazole is initiated, discontinued or dose changed.

Tadalafil: Miconazole may reduce the metabolism of Tadalafil. Concomitant therapy should be avoided if possible due to high risk of Tadalafil toxicity.

Tamoxifen: Miconazole may decrease the therapeutic effect of Tamoxifen by decreasing the production of active metabolites. Concomitant therapy should be avoided.

Tamsulosin: Miconazole, a CYP3A4/2D6 inhibitor, may decrease the metabolism and clearance of Tamsulosin, a CYP3A4/2D6 substrate. Monitor for changes in therapeutic/adverse effects of Tamsulosin if Miconazole is initiated, discontinued, or dose changed.

Telithromycin: Miconazole may increase the plasma concentration of Telithromycin. Consider alternate therapy or monitor therapeutic/adverse effects.

Temsirolimus: Miconazole may inhibit the metabolism and clearance of Temsirolimus. Concomitant therapy should be avoided.

Teniposide: The strong CYP3A4 inhibitor, Miconazole, may decrease the metabolism and clearance of Teniposide, a CYP3A4 substrate. Consider alternate therapy or monitor for changes in the therapeutic/adverse effects of Teniposide if Miconazole is initiated, discontinued or dose changed.

Tiagabine: The strong CYP3A4 inhibitor, Miconazole, may decrease the metabolism and clearance of Tiagabine, a CYP3A4 substrate. Consider alternate therapy or monitor for changes in the therapeutic/adverse effects of Tiagabine if Miconazole is initiated, discontinued or dose changed.

Tizanidine: Miconazole may decrease the metabolism and clearance of Tizanidine. Consider alternate therapy or use caution during co-administration.

Tolbutamide: Miconazole, a strong CYP2C9 inhibitor, may decrease the metabolism and clearance of Tolbutamide, a CYP2C9 substrate. Consider alternate therapy or monitor for changes in Tolbutamide therapeutic and adverse effects if Miconazole is initiated, discontinued or dose changed.

Tolterodine: Miconazole may decrease the metabolism and clearance of Tolterodine. Adjust Tolterodine dose and monitor for efficacy and toxicity.

Torasemide: Miconazole, a strong CYP2C9 inhibitor, may increase the serum concentration of Torasemide, a CYP2C9 substrate, by decreasing Torasemide metabolism and clearance. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of Torasemide if Miconazole is initiated, discontinued or dose changed.

Tramadol: Miconazole may increase Tramadol toxicity by decreasing Tramadol metabolism and clearance. Miconazole may decrease the effect of Tramadol by decreasing active metabolite production.

Trazodone: The CYP3A4 inhibitor, Miconazole, may increase Trazodone efficacy/toxicity by decreasing Trazodone metabolism and clearance. Consider alternate therapy or monitor for changes in Trazodone efficacy/toxicity if Miconazole is initiated, discontinued or dose changed.

Trimethoprim: The strong CYP2C9 inhibitor, Miconazole, may decrease the metabolism and clearance of Trimethoprim, a CYP2C9 substrate. Consider alternate therapy or monitor for changes in therapeutic and adverse effects of Trimethoprim if Miconazole is initiated, discontinued or dose changed.

Trimipramine: The strong CYP3A4/2D6/2C19 inhibitor, Miconazole, may decrease the metabolism and clearance of Trimipramine, a CYP3A4/2D6/2C19 substrate. Consider alternate therapy or monitor for changes in therapeutic and adverse effects of Trimipramine if Miconazole is initiated, discontinued or dose changed.

Vardenafil: Miconazole, a strong CYP3A4 inhibitor, may reduce the metabolism and clearance of Vardenafil. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of Vardenafil.

Venlafaxine: Miconazole, a CYP2D6 and CYP3A4 inhibitor, may decrease the metabolism and clearance of Venlafaxine, a CYP2D6 and CYP3A4 substrate. Monitor for changes in therapeutic/adverse effects of Venlafaxine if Miconazole is initiated, discontinued, or dose changed.

Verapamil: Miconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of Veramapil, a CYP3A4 substrate, by decreasing its metabolism and clearance. Consider alternate therapy or monitor for changes in the therapeutic/adverse effects of Verapamil if Miconazole is initiated, discontinued or dose changed.

Vinblastine: Miconazole, a strong CYP3A4 inhibitor, may decrease the metabolism of Vinblastine. Consider alternate therapy to avoid Vinblastine toxicity. Monitor for changes in the therapeutic/adverse effects of Vinblastine if Miconazole is initiated, discontinued or dose changed.

Vincristine: Miconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of Vincristine by decreasing its metabolism. Consider alternate therapy to avoid Vincristine toxicity. Monitor for changes in the therapeutic and adverse effects of Vincristine if Miconazole is initiated, discontinued or dose changed.

Vinorelbine: Miconazole, a strong CYP3A4 inhibitor, may increase the serum concentration of Vinorelbine by decreasing its metabolism. Consider alternate therapy to avoid Vinorelbine toxicity. Monitor for changes in the therapeutic and adverse effects of Vinorelbine if Miconazole is initiated, discontinued or dose changed.

Voriconazole: Miconazole, a strong CYP2C9 inhibitor, may increase the serum concentration of voriconazole by decreasing its metabolism. Monitor for changes in the therapeutic and adverse effects of voriconazole if miconazole is initiated, discontinued or dose changed.

Warfarin: Miconazole, a strong CYP2C9 inhibitor, may decrease the metabolism of warfarin. Consider alternate therapy or monitor for changes in the therapeutic and adverse effects of warfarin if miconazole is initiated, discontinued or dose changed.