From the Guidelines
Treatment is recommended for this patient with abundant vaginal discharge and a fishy odor, despite not having a clear diagnosis of bacterial vaginosis (BV) on vaginal sampling. The patient's symptoms strongly suggest bacterial vaginosis even though laboratory findings show only altered flora without meeting full Nugent or Amsel criteria for BV. This clinical presentation represents a dysbiosis of the vaginal microbiome with an overgrowth of anaerobic bacteria that produce amines responsible for the characteristic fishy odor.
Key Considerations
- The first-line treatment would be metronidazole, either as a 500mg oral dose twice daily for 7 days, or as a vaginal gel (0.75%) applied once daily for 5 days, as recommended by the CDC guidelines 1.
- Alternatively, clindamycin cream (2%) applied vaginally at bedtime for 7 days can be used, as suggested by the CDC guidelines 1.
- Treatment aims to restore normal vaginal flora dominated by Lactobacillus species.
- If symptoms persist after treatment, a follow-up examination is warranted to rule out other causes or mixed infections.
- The patient should avoid douching, use of scented products in the genital area, and unprotected sex during treatment, as these practices can exacerbate the condition or lead to recurrence 2, 3.
Rationale
- The benefits of therapy for BV in non-pregnant women are to relieve vaginal symptoms and signs of infection, and reduce the risk for infectious complications after abortion or hysterectomy, as stated in the CDC guidelines 4.
- The patient's symptoms and clinical presentation are consistent with BV, despite not meeting the full diagnostic criteria, and treatment is recommended to alleviate symptoms and prevent potential complications.
- The CDC guidelines recommend treatment for symptomatic BV, regardless of the presence of a clear diagnosis, to relieve symptoms and prevent complications 1, 5.
From the FDA Drug Label
Metronidazole vaginal gel is indicated in the treatment of bacterial vaginosis (formerly referred to as Haemophilus vaginitis, Gardnerella vaginitis, nonspecific vaginitis, Corynebacterium vaginitis, or anaerobic vaginosis) NOTE: For purposes of this indication, a clinical diagnosis of bacterial vaginosis is usually defined by the presence of a homogeneous vaginal discharge that (a) has a pH of greater than 4. 5, (b) emits a “fishy” amine odor when mixed with a 10% KOH solution, and (c) contains clue cells on microscopic examination.
The patient does not have a confirmed diagnosis of bacterial vaginosis, as the label specifies that a diagnosis is usually defined by the presence of specific criteria, which are not all met in this case.
- The patient has abundant leucorrhea (vaginal discharge) and a fishy odor, but
- There is no frank vaginosis and
- Only an altered vaginal flora. Since the diagnosis of bacterial vaginosis is not confirmed, the patient should not be treated with metronidazole vaginal gel based on the information provided 6.
From the Research
Patient Condition
- The patient has abundant leucorrhea (vaginal discharge) and a fishy odor, but no frank vaginosis and an altered vaginal flora.
Treatment Considerations
- According to 7, bacterial vaginosis is characterized by a shift in normal vaginal flora from aerobic to anaerobic flora, and more than half of women with bacterial vaginosis have no symptoms.
- However, the condition is not entirely benign, and the presence of potentially pathogenic bacteria can put women at risk for postoperative morbidity and adverse obstetric outcomes.
- The study 8 recommends treatment with metronidazole or clindamycin for bacterial vaginosis, which is characterized by a musty or fishy vaginal odor and a thin, white vaginal discharge.
- Another study 9 compares the efficacy of oral metronidazole, metronidazole vaginal gel, and clindamycin vaginal cream for the treatment of bacterial vaginosis, and finds that all three treatments have similar cure rates.
Treatment Options
- Metronidazole or clindamycin are recommended for the treatment of bacterial vaginosis 7, 8.
- Oral metronidazole, metronidazole vaginal gel, and clindamycin vaginal cream have similar cure rates for the treatment of bacterial vaginosis 9.
- Ketoconazole/clindamycin and metronidazole/nistatine combinations have also been compared for the treatment of vaginitis and bacterial vaginosis, with ketoconazole/clindamycin showing superior results in some cases 10.
Altered Vaginal Flora
- The study 11 notes that the normal vaginal flora is complex and can include over a dozen different organisms, and that the balance of the flora can vary from individual to individual.
- An understanding of the normal vaginal flora can help guide the diagnosis and treatment of abnormal conditions, such as bacterial vaginosis 11.