Treatment of Vaginal Greenish Discharge
Greenish vaginal discharge is most characteristic of trichomoniasis and should be treated with oral metronidazole or tinidazole, with concurrent treatment of all sexual partners mandatory to prevent reinfection. 1
Diagnostic Confirmation
Before initiating treatment, confirm the diagnosis through:
- Wet mount microscopy to identify motile trichomonads, which is the classic presentation of greenish discharge 1
- Vaginal pH measurement using narrow-range pH paper; pH >4.5 supports trichomoniasis or bacterial vaginosis, while pH ≤4.5 suggests candidiasis 2
- Nucleic acid amplification testing (NAAT) is the CDC-recommended diagnostic method for trichomoniasis in symptomatic or high-risk women, as it is more sensitive than microscopy 3
First-Line Treatment for Trichomoniasis
Metronidazole 2 g orally as a single dose is the standard treatment, achieving cure rates of 90-95% 1, 4
Alternative regimens include:
- Tinidazole 2 g orally as a single dose, with reported cure rates ranging from 92-100% in published studies 5
- Metronidazole 500 mg orally twice daily for 7 days (if single-dose therapy fails) 1
Critical Management Points
Partner treatment is mandatory - sexual partners must be treated simultaneously to prevent reinfection, even if asymptomatic 1, 5
Instruct patients to abstain from sexual intercourse until both patient and partner(s) complete treatment and are asymptomatic 1
Advise patients to avoid alcohol during metronidazole treatment and for 24 hours after completion due to disulfiram-like reactions 1
Special Populations
Pregnant women: Symptomatic pregnant women should be treated with oral metronidazole to relieve symptoms, as trichomoniasis is associated with premature rupture of membranes, preterm delivery, and low birth weight 1
HIV-infected patients: Use the same treatment regimen as HIV-negative patients 1
Alternative Diagnoses to Consider
If greenish discharge is accompanied by:
Fishy odor and pH >4.5: Consider bacterial vaginosis, which presents with homogeneous white-to-gray discharge but can appear greenish; treat with metronidazole 500 mg orally twice daily for 7 days or intravaginal metronidazole gel 0.75% once daily for 5 days 1, 2
Pruritus and pH ≤4.5: Consider vulvovaginal candidiasis (though white discharge is more typical); confirm with KOH preparation showing yeast/pseudohyphae and treat with fluconazole 150 mg orally as a single dose or topical azoles 1, 6, 2
Follow-Up
Follow-up is unnecessary for patients who become asymptomatic after treatment 1
Return for re-evaluation only if symptoms persist or recur within 2 months, which may indicate treatment failure, reinfection from an untreated partner, or an alternative diagnosis 1, 2