MONISTAT 3
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MONISTAT 3 (MONISTAT 3).
Miconazole nitrate, an imidazole antifungal, inhibits fungal cytochrome P450 14α-demethylase, blocking ergosterol synthesis and disrupting fungal cell membrane integrity.
| Metabolism | Hepatic via CYP3A4; minimal systemic absorption after intravaginal administration (<1.4%). |
| Excretion | Primarily fecal (97%) via biliary excretion; renal excretion of unchanged drug is negligible (<1%). |
| Half-life | Terminal elimination half-life is approximately 30 hours after topical vaginal application; prolonged in hepatic impairment. |
| Protein binding | Approximately 90-95% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Apparent volume of distribution is approximately 2.8 L/kg after IV administration (for systemic formulation), indicating extensive tissue penetration; vaginal absorption minimal, with Vd not clinically relevant for topical use. |
| Bioavailability | Topical vaginal: approximately 5-10% systemically absorbed; oral: minimally absorbed (<1%) due to poor solubility. |
| Onset of Action | Clinical relief of symptoms (itching, discharge) typically begins within 24 hours of first dose. |
| Duration of Action | Therapeutic effect persists for up to 3 days after completion of 3-day regimen; full eradication may require 7 days for non-responsive cases. |
One vaginal suppository (200 mg miconazole nitrate) intravaginally at bedtime for 3 consecutive days; or one applicatorful (5 g) of 4% vaginal cream intravaginally at bedtime for 7 days.
| Dosage form | CREAM |
| Renal impairment | No dosage adjustment required for renal impairment; data limited for severe impairment (eGFR <30 mL/min). |
| Liver impairment | No dosage adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B); use with caution in severe impairment (Child-Pugh C) due to lack of data. |
| Pediatric use | Children ≥12 years of age: same as adult dosing (200 mg vaginal suppository at bedtime for 3 days or 4% cream for 7 days). Children <12 years: not recommended; safety and efficacy not established. |
| Geriatric use | No specific dosage adjustment required; use same as adult dosing. Absorption does not significantly differ in elderly patients. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for MONISTAT 3 (MONISTAT 3).
| Breastfeeding | Miconazole is minimally absorbed systemically after vaginal application; therefore, levels in breast milk are expected to be negligible. The M/P ratio has not been determined, but based on low bioavailability, excretion into breast milk is considered unlikely. Short-term use during lactation is generally considered compatible. |
| Teratogenic Risk | Miconazole nitrate (MONISTAT 3) is pregnancy category C. In animal studies, miconazole has shown embryotoxicity and fetotoxicity at high doses, but no well-controlled studies exist in pregnant women. Systemic absorption from vaginal use is minimal, but first-trimester use is generally avoided unless benefit outweighs risk. Second and third trimester use for localized infections is considered low risk due to limited systemic exposure. |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to miconazole or any component; concurrent use with CYP3A4 substrates that have narrow therapeutic index (e.g., cisapride, pimozide, quinidine, ergot alkaloids) due to potential for increased plasma levels and toxicity.
| Precautions | Hepatic impairment; use during pregnancy (Category C) only if clearly needed; possible hypersensitivity reactions including anaphylaxis; discontinue if irritation or sensitization occurs; may interact with warfarin (enhances anticoagulant effect). |
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| Fetal Monitoring | No specific maternal or fetal monitoring is required beyond routine prenatal care. However, if symptoms persist or infection recurs, confirm diagnosis and consider alternative therapy. |
| Fertility Effects | There are no known adverse effects of miconazole on female or male fertility. Animal studies show no impairment of fertility at clinically relevant doses. |