METROCREAM
Clinical safety rating: caution
Comprehensive clinical and safety monograph for METROCREAM (METROCREAM).
Metrocream contains metronidazole, a nitroimidazole antibiotic. Its mechanism involves reduction of the nitro group by bacterial nitroreductases, forming toxic intermediates that damage DNA and inhibit nucleic acid synthesis. It also exhibits anti-inflammatory effects by reducing reactive oxygen species and modulating neutrophil chemotaxis.
| Metabolism | Hepatic metabolism via oxidation and glucuronidation. Metronidazole is metabolized by CYP450 enzymes, primarily CYP2A6 and CYP3A4, forming metabolites such as hydroxy metronidazole and acetic acid metabolite. |
| Excretion | Renal: 70-80% as unchanged drug and metabolites. Fecal/biliary: ~20%. |
| Half-life | Terminal elimination half-life: 6-8 hours. Not extended in renal impairment. |
| Protein binding | Metronidazole: <20% bound to plasma proteins. |
| Volume of Distribution | Vd: ~0.6-0.7 L/kg, indicating distribution into total body water. |
| Bioavailability | Topical: Systemic bioavailability approximately 0.1-1% of applied dose for metronidazole 1% cream. |
| Onset of Action | Topical: Improvement in inflammatory lesions of rosacea noted within 2-3 weeks of twice-daily application. |
| Duration of Action | Topical: Duration of action persists with continued application; sustained use required for maintenance. |
| Action Class | 5-Nitroimidazole (Antiprotozoal & Antibacterial) |
| Brand Substitutes | Unimegyl 400mg Tablet, Metgyl 400mg Tablet, Aldezol 400mg Tablet, Metrocon 400mg Tablet, Met 400mg Tablet, Tosgyl 200mg Tablet, Aristogyl 200mg Tablet, Metgyl 200mg Tablet, Metron 200mg Tablet, Unimegyl 200mg Tablet |
Topical, apply a thin film to affected area once or twice daily.
| Dosage form | CREAM |
| Renal impairment | No adjustment required for topical application. |
| Liver impairment | No adjustment required for topical application. |
| Pediatric use | Safety and efficacy not established in pediatric patients under 18 years. |
| Geriatric use | No specific dose adjustment recommended; use caution due to potential skin atrophy. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for METROCREAM (METROCREAM).
| Breastfeeding | Minimal systemic absorption of metronidazole after topical application (approximately 2%) results in negligible transfer into breast milk. M/P ratio is not established for topical route. Use during breastfeeding is considered compatible; however, avoid application to breast area to prevent infant exposure. |
| Teratogenic Risk | Topical metronidazole (MetroCream) is considered low risk for teratogenicity. In animal studies, no evidence of fetal harm was observed at topical doses. For oral metronidazole, data do not suggest an increased risk of major malformations; however, use in first trimester is generally avoided due to theoretical risk. For topical application, systemic absorption is minimal (approximately 2%), and the drug is considered safe throughout pregnancy, with no known fetal risks. |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to metronidazole or any component of the formulation.
| Precautions | Avoid contact with eyes. Use with caution in patients with blood dyscrasias or history of hypersensitivity to metronidazole. Prolonged use may result in overgrowth of non-susceptible organisms. Discontinue if irritation occurs. |
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| Fetal Monitoring | No specific maternal or fetal monitoring is required beyond routine prenatal care due to low systemic absorption. |
| Fertility Effects | No known adverse effects on fertility in males or females at topical doses. Systemic metronidazole has no established impact on fertility. |