Metronidazole is an antibiotic that is prescribed to treat bacterial infections of the vagina, liver, stomach, joints, skin, brain and spinal cord, heart, lungs, or bloodstream. The medicine is even utilized to treat trichomoniasis, a sexually transmitted infection (STI) triggered by a parasite. Usually, both sexual partners are treated at an identical time, precise if one has no symptoms. Do not utilize metronidazole to treat any infection that has not been reviewed by your healthcare provider. This medicine is not authorized to treat vaginal infections in girls who have not formed having menstrual periods. It is usually provided for up to 10 days in a sequence.