Bacterial vaginosis results from an overpopulation of anaerobic bacteria that displaces the normal resident bacteria of the vagina, Lactobacillus acidophilus. Antibiotic treatments for bacterial vaginosis include metronidazole and clindomycin, which target the anaerobic bacteria to restore the normal balance of healthy bacteria in your vagina. The antibiotics can be administered orally or through a vaginal cream or gel.
Oral
According to "Primary Care for Women," doctors usually recommend pills containing the antibiotic metronidazole for treatment of bacterial vaginosis. Metronidazole targets anaerobic bacteria such as species of Prevotella, Peptostreptococcus and Mobiluncus, as well as Gardnerella vaginalis and Mycoplasma hominis, the agents that often overgrow to cause bacterial vaginosis. Metronidazole sells under the brand names of Flagyl, MetroCream, MetroGel, Noritate and Vandazole. It works by unwinding the DNA helix and breaking the DNA strands of its target bacteria to cause cell death.
Metronidazole pills are effective, but because they disperse through your entire body, they can have side effects like flushing, headache, nausea, a metallic taste in your mouth and chest pain. Your urine might turn brown or black. Some doctors recommend the use of a metronidazole vaginal gel instead.
Vaginal
Doctors commonly prescribe antibiotic gels or treatments for bacterial vaginosis. Your doctor might recommend daily treatment for five days using a vaginal applicator containing 0.75 percent metronidazole gel, or for seven days using a vaginal applicator containing 2 percent clindamycin cream. Like metronidazole, the antibiotic clindamycin targets the anaerobic bacteria that cause bacterial vaginosis. Clindamycin sells under the brand names Cleocin, Clidagel, Clindesse and Evoclin. Clindamycin binds to the cellular machinery that strings together amino acids, preventing protein production and ultimately killing its target bacteria.
According to the Merck manual, if you use clindamycin cream to treat bacterial vaginosis, you should not use latex products for birth control during treatment. Clindamycin cream weakens latex and could cause condoms or diaphragms to break.
Alternative
The recommended dosage of metronidazole is 500 mg twice a day for seven days. You should notice some relief from your symptoms after about two days. Alternatively, your doctor might prescribe a single dose of 2 grams of metronidazole.
Clindamycin comes as a pill and your doctor might recommend that you take 300 mg twice a day for seven days. Clindamycin also comes in 100 g ovules, a type of vaginal suppository that you insert once a day for three days.
References
- "Primary Care for Women"; Phyllis Leppert and Jeffrey Peipert; 2004
- Merck Manual On-Line: Vaginitis
- Merck Manual On-Line: Metronidazole
- Merck Manual On-Line: Clindamycin
