MONISTAT
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MONISTAT (MONISTAT).
Miconazole, the active ingredient in MONISTAT, inhibits fungal CYP51 (lanosterol 14-alpha-demethylase), blocking ergosterol synthesis and disrupting fungal cell membrane integrity, leading to cell death.
| Metabolism | Hepatic metabolism via CYP3A4 isoenzyme with oxidation and O-dealkylation. |
| Excretion | Primarily fecal (approximately 90%) as unchanged drug; less than 2% renal elimination. |
| Half-life | Approximately 90-120 minutes; supports twice-daily local dosing. |
| Protein binding | Highly protein bound (>90%), primarily to albumin. |
| Volume of Distribution | 0.5-1.0 L/kg; indicates extensive tissue penetration after systemic absorption, though systemic levels are low with topical use. |
| Bioavailability | Intravaginal: <1% systemic absorption; topical: approximately 1-2%. |
| Onset of Action | Intravaginal: symptomatic relief within 24 hours; topical: itching relief within 24-72 hours. |
| Duration of Action | Intravaginal: 1-3 days depending on formulation; topical: 12-24 hours per application. |
| Molecular Weight | 479.15 |
Intravaginal: 200 mg suppository at bedtime for 3 days, or 100 mg suppository at bedtime for 7 days, or 2% cream 5 g intravaginally at bedtime for 7 days. Topical: Apply 2% cream twice daily for 2-4 weeks.
| Dosage form | INJECTABLE |
| Renal impairment | No dose adjustment required for renal impairment; miconazole is minimally absorbed systemically. |
| Liver impairment | No formal studies; use caution in severe hepatic impairment due to possible accumulation if systemic absorption occurs. |
| Pediatric use | Children ≥12 years: same as adult dosing. Children <12 years: not recommended or use under specialist guidance. |
| Geriatric use | No specific dose adjustment; same as adult dosing. Monitor for local irritation or sensitivity. |
| 1st trimester | Topical miconazole is generally considered safe in the first trimester based on observational studies; however, intravaginal use is typically avoided unless benefit outweighs risk due to limited data. |
| 2nd trimester | Topical miconazole is safe in second trimester; intravaginal use is acceptable with caution. |
| 3rd trimester | Topical miconazole is safe in third trimester; intravaginal use is acceptable near term. |
Clinical note
Comprehensive clinical and safety monograph for MONISTAT (MONISTAT).
| Placental transfer | Minimal to no placental transfer with topical application; systemic absorption is <1.5% with intravaginal use. |
| Breastfeeding | Topical miconazole has minimal systemic absorption and is considered compatible with breastfeeding. Apply to nipple only if necessary and wipe off before feeding. |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to miconazole or any componentHistory of hypersensitivity to other azole antifungals
| Precautions | May interact with warfarin, potentiating anticoagulant effect; hypersensitivity reactions including urticaria, pruritus, and angioedema; avoid contact with eyes; discontinue if irritation or sensitivity occurs; do not use during menstruation; for vaginal use only. |
| Food/Dietary | No significant food interactions. However, avoid excessive sugar intake during therapy as it may promote yeast overgrowth. Grapefruit juice is not known to interact with miconazole topical products. |
| Clinical Pearls |
Loading safety data…
| Lactation Rating | L2 (Probably Compatible) |
| Teratogenic Risk | Category C. No evidence of teratogenicity in animal studies; limited human data. Intravaginal absorption is minimal, systemic exposure low. Risk to fetus not ruled out; use only if clearly needed. |
| Fetal Monitoring | No specific maternal or fetal monitoring required beyond standard prenatal care. Monitor for signs of vaginal irritation or hypersensitivity. |
| Fertility Effects | No known effect on fertility in animal or human studies. Reversible suppression of spermatogenesis reported in animal models at high systemic doses, unlikely with intravaginal use. |
| Miconazole (MONISTAT) is an azole antifungal for topical intravaginal use. It is effective against Candida albicans and other Candida species. Do not use if patient has abdominal pain, fever, or foul-smelling discharge; these may indicate pelvic inflammatory disease. Discontinue if irritation or hypersensitivity occurs. Avoid concurrent use of latex condoms or diaphragms as the product base can weaken latex. |
| Patient Advice | Complete the full course of treatment even if symptoms improve, typically 1-7 days depending on formulation. · Do not use during menstruation; wait until after menses to start treatment. · Avoid sexual intercourse during treatment and for 3 days after completing therapy. · Do not use tampons, douches, spermicides, or other vaginal products while using this medication. · Wash hands before and after applying the cream or inserting the suppository. · If symptoms persist beyond 7 days, consult a healthcare provider. Recurrent infections may require oral therapy or workup for diabetes or immunosuppression. · Report any signs of allergic reaction: rash, hives, difficulty breathing, or swelling of the face, lips, or throat. |