PREPARATIONS: Topical gel (0.75%, 1%), cream or lotion (0.75%): Vaginal gel (0.75%, 1.3%).
DRUG INTERACTIONS: Alcoholic beverages should not be consumed while being treated with metronidazole vaginal gel since this may result in:
Oral metronidazole interacts with warfarin (Coumadin), increasing the latter's blood-thinning properties. Little metronidazole is absorbed topically or from the vagina, and it is not known if the low blood levels achieved with topical or vaginal metronidazole can result in this interaction.
PREGNANCY AND BREASTFEEDING SAFETY: Animal studies have not demonstrated a risk to the fetus, but there are no adequate studies in pregnant women.
Orally administered metronidazole is secreted in human milk in concentrations that are similar to concentrations in the mother's blood. Although metronidazole concentration in blood after vaginal or topical administration is small, potential effects on the infant still should be considered.
STORAGE: Topical forms of metronidazole should be stored at room temperature, 15 C - 30 C (59 F - 86 F).
DOSING: To treat rosacea, a thin film of metronidazole gel should be rubbed on affected areas once or twice daily. The usual dose of vaginal metronidazole gel is one applicator full (containing 37.5mg of metronidazole) intravaginally twice daily for five days. It should be applied once in the morning and once in the evening.
DRUG CLASS AND MECHANISM: Metronidazole is a man-made drug that is effective against certain bacteria and parasites (protozoa). The topical forms of metronidazole are used for treating vaginal infections with protozoa such as Trichomonas vaginalis, amoeba, and Giardia and also is effective against anaerobic bacterial infections. (Anaerobic bacteria are a type of bacteria that can grow without the presence of oxygen.) Metronidazole gel also is used for treating rosacea, a type of skin rash. Metronidazole was approved by the FDA in 1963.
Medically reviewed by Eni Williams, PharmD
Reference: FDA Prescribing Information
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