MONISTAT-DERM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MONISTAT-DERM (MONISTAT-DERM).
Miconazole inhibits fungal lanosterol 14α-demethylase, a cytochrome P450 enzyme, thereby blocking ergosterol synthesis and disrupting fungal cell membrane integrity.
| Metabolism | Miconazole is primarily metabolized via oxidative N-dealkylation and aromatic hydroxylation, mainly by CYP3A4 and CYP2C9. |
| Excretion | Primarily fecal (biliary) elimination as unchanged drug and metabolites; <1% renal excretion of unchanged drug. |
| Half-life | Terminal elimination half-life is approximately 24–30 hours, supporting twice-daily or once-daily dosing for dermatologic infections. |
| Protein binding | Miconazole is >90% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Approximately 20 L/kg, indicating extensive tissue distribution (e.g., skin, lungs, liver). |
| Bioavailability | Topical: Systemic absorption is minimal (<1%), resulting in negligible bioavailability; oral: incomplete (25–30% due to first-pass metabolism), but not used for dermatologic indications. |
| Onset of Action | Topical: Relief from itching and discomfort begins within 24–72 hours; detectable fungistatic levels in stratum corneum within hours of application. |
| Duration of Action | Topical: Sustained antifungal activity persists for at least 24 hours after a single application; clinical cure typically requires 2–4 weeks of treatment. |
| Molecular Weight | 416.13 |
Topical: Apply once daily to affected areas for 2-4 weeks. Vaginal: One 200 mg suppository at bedtime for 3 days, or one 100 mg suppository at bedtime for 7 days, or one 1200 mg suppository as a single dose.
| Dosage form | LOTION |
| Renal impairment | No specific dose adjustment required for topically applied miconazole. For systemic exposure negligible, no GFR-based modifications needed. |
| Liver impairment | No specific dose adjustments for topical use. Caution in severe hepatic impairment due to potential systemic absorption from extensive application, but no established guidelines. |
| Pediatric use | Children ≥2 years: Apply once daily to affected area for 2-4 weeks. For vaginal use in adolescents: Same as adult dosing. |
| Geriatric use | No specific dose adjustment needed. Use caution with extensive application due to thinner skin and potential increased absorption. |
| 1st trimester | Avoid in first trimester; limited data; animal studies show embryo toxicity at high doses. Use only if clearly needed. |
| 2nd trimester | Generally considered safe for short-term topical use; systemic absorption minimal. Caution with prolonged use. |
| 3rd trimester | Safe for short-term topical use; low systemic exposure. Avoid excessive use near term. |
Clinical note
Comprehensive clinical and safety monograph for MONISTAT-DERM (MONISTAT-DERM).
| Placental transfer | Limited data; topical miconazole results in negligible systemic levels, so placental transfer is minimal. Vaginal administration may yield low but detectable levels. |
| Breastfeeding | Topical miconazole is poorly absorbed systemically, making it compatible with breastfeeding. Avoid application to the breast or nipple area to prevent infant ingestion. Brief, small area use is considered low risk. |
■ FDA Black Box Warning
None.
| Serious Effects |
Known hypersensitivity to miconazole or any componentSevere hepatic impairment (systemic use)Concurrent use with terfenadine, astemizole, or cisapride (systemic miconazole increases risk of QT prolongation)
| Precautions | Hypersensitivity reactions; avoid occlusive dressings; not for ophthalmic or intravaginal use; potential for hepatotoxicity with systemic absorption. |
| Food/Dietary | No clinically significant food interactions. Avoid alcohol if using oral miconazole (not applicable to topical formulation). No dietary restrictions required. |
| Clinical Pearls |
Loading safety data…
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | In pregnancy category C. Systemic absorption is minimal; however, use in the first trimester is avoided unless clearly necessary. No evidence of teratogenicity in animal studies with topical application. |
| Fetal Monitoring | None specifically required due to minimal systemic absorption. Monitor for local hypersensitivity or irritation. |
| Fertility Effects | No data on human fertility. Animal studies show no impairment of fertility with topical miconazole. |
| MONISTAT-DERM (miconazole nitrate) is a broad-spectrum antifungal effective against dermatophytes and Candida. For tinea pedis, treat for 4 weeks to prevent recurrence. Avoid occlusion unless directed, as it may increase irritation. In intertriginous areas, apply sparingly to prevent maceration. Combination with low-potency corticosteroid may reduce inflammation in severe cases, but monotherapy is preferred. |
| Patient Advice | Apply the cream to the affected area and surrounding skin twice daily (morning and evening). · Wash hands before and after application; do not use in eyes or ingest. · Continue use for the full prescribed duration (e.g., 2 weeks for tinea cruris, 4 weeks for tinea pedis) even if symptoms improve. · Avoid sharing towels or clothing to prevent reinfection. · Notify your doctor if rash worsens or if burning, blistering, or discharge occurs. |