MICONAZOLE NITRATE COMBINATION PACK
Clinical safety rating: safe
Warfarin metabolism is inhibited increasing INR For topical use only not for ophthalmic use.
Miconazole nitrate inhibits fungal lanosterol 14α-demethylase (CYP51), disrupting ergosterol synthesis and causing fungal cell membrane damage.
| Metabolism | Hepatic metabolism via CYP450 enzymes; primarily excreted in feces and urine. |
| Excretion | Primarily fecal (biliary) as unchanged drug and metabolites (~50-60%); renal excretion accounts for <20% of the dose, mostly as inactive metabolites. |
| Half-life | Terminal elimination half-life is approximately 20-25 hours, but can be prolonged to 30-40 hours in patients with hepatic impairment. |
| Protein binding | Approximately 88-93% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Apparent Vd is about 20-30 L/kg, indicating extensive tissue distribution; clinical meaning: high tissue penetration, but minimal systemic absorption after topical use. |
| Bioavailability | Topical/ vaginal: systemic bioavailability is minimal (<1% of dose absorbed); oral: bioavailability is negligible due to poor absorption (not used systemically). |
| Onset of Action | Topical: antifungal effect begins within 24-48 hours of first application; vaginal: symptomatic relief often within 1-3 days. |
| Duration of Action | Topical: drug persists in skin for up to 4 days after application; vaginal: local concentrations remain above MIC for approximately 72 hours after single dose. |
Intravaginally, one suppository (100 mg miconazole nitrate) once daily at bedtime for 7 days or one suppository (200 mg) once daily for 3 days, combined with topical application of miconazole nitrate cream (2%) to the vulvar area twice daily for 7 days.
| Dosage form | CREAM, SUPPOSITORY |
| Renal impairment | No dose adjustment is required for renal impairment. Miconazole nitrate is minimally absorbed systemically after topical or intravaginal administration. |
| Liver impairment | No specific dose adjustment guidelines are available for hepatic impairment. Given low systemic absorption, caution is advised in severe hepatic impairment due to potential for accumulation of excipients. |
| Pediatric use | Not recommended for use in pediatric patients below 12 years of age. For adolescents 12 years and older, dosing is the same as adult dosing: one 100 mg suppository intravaginally at bedtime for 7 days, or one 200 mg suppository for 3 days, with topical cream applied to vulvar area twice daily for 7 days. |
| Geriatric use | No specific dose adjustment required. Use the same dosing regimen as for younger adults. Caution in elderly due to potential for vaginal dryness or mucosal irritation; consider shorter treatment duration if tolerated. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Warfarin metabolism is inhibited increasing INR For topical use only not for ophthalmic use.
| FDA category | Human |
| Breastfeeding | Miconazole nitrate is excreted into breast milk in negligible amounts after topical/vaginal application due to low systemic absorption. The M/P ratio has not been determined but is expected to be very low. No adverse effects in breastfed infants have been reported. The American Academy of Pediatrics considers miconazole compatible with breastfeeding. Caution is advised if applied to the breast to avoid infant ingestion. |
| Teratogenic Risk |
■ FDA Black Box Warning
None.
| Common Effects | vaginal yeast infections |
| Serious Effects |
["Hypersensitivity to miconazole nitrate or any component of the formulation"]
| Precautions | ["For external use only; avoid contact with eyes","Discontinue if irritation or hypersensitivity occurs","May interact with warfarin and other oral anticoagulants (enhanced anticoagulant effect)"] |
Loading safety data…
| Miconazole nitrate is an azole antifungal. Systemic absorption after topical or vaginal use is minimal (approximately 1.4%). No increased risk of major birth defects has been observed in human studies with topical/vaginal use. In animal studies, subcutaneous doses up to 80 mg/kg/day (maternal toxic) were not teratogenic; at higher doses, fetal loss and delayed ossification occurred. First trimester: limited data suggest no significant risk; second and third trimester: considered safe when used as directed. Overall, risk is low due to minimal systemic exposure. |
| Fetal Monitoring | No specific monitoring is required beyond routine prenatal care. Monitor for local irritation, allergic reactions, or signs of systemic toxicity (rare). In pregnancy, ensure correct diagnosis of vaginal candidiasis and consider alternative treatments if recurrent. |
| Fertility Effects | No adverse effects on fertility have been reported in animal or human studies. The minimal systemic absorption makes significant impact on fertility unlikely. No data on impairment of male or female fertility. |