Trichomonas (T. vaginalis) Infection Treatment
Trichomoniasis is treated with oral nitroimidazoles. For women, multidose metronidazole is recommended. For men, single-dose metronidazole is recommended. [1]
Medication Selection Algorithm
- Nitroimidazoles are the only medications with clinically demonstrated efficacy against T. vaginalis infection. [1]
- Metronidazole is first-line for both women and men. [1]
- Tinidazole is an alternative regimen for women and men. [1]
Core Recommended Regimens
Treatment Regimen for Women
- Metronidazole 500 mg orally 2 times/day for 7 days is recommended. [1]
Treatment Regimen for Men
- Metronidazole 2 g orally in a single dose is recommended. [1]
Alternative Regimen
- Tinidazole 2 g orally in a single dose is an alternative regimen for women and men. [1]
Key Evidence Supporting These Regimens
- Multidose metronidazole (500 mg orally 2 times/day for 7 days) reduced the proportion of women retesting positive at a 1-month test-of-cure visit by half compared with single-dose 2 g metronidazole. [1]
- Recommended metronidazole regimens have demonstrated cure rates of approximately 84%–98%. [1]
- Recommended tinidazole regimens have demonstrated cure rates of approximately 92%–100%. [1]
Monotherapy Versus Combination Therapy
- Treatment should be provided with a single systemic nitroimidazole regimen based on sex. [1]
- Metronidazole gel is not recommended because it does not reach therapeutic levels in the urethra and perivaginal glands and is less efficacious than oral metronidazole. [1]
Partner Management and Sexual Abstinence
- Concurrent treatment of all sex partners is vital for preventing reinfection. [1]
- Sex should be avoided until therapy has been completed and symptoms have resolved for the patient and sex partners. [1]
- Expedited partner therapy (EPT) may be used in jurisdictions where permitted by law. [1]
Treatment Initiation Thresholds and Follow-Up Testing
- Retesting is recommended for sexually active women approximately 3 months after initial treatment because of a high reinfection rate. [1]
- If retesting at 3 months is not possible, retesting should occur at the next medical visit within 12 months after initial treatment. [1]
- Data are insufficient to support routine retesting of men after treatment. [1]
- NAAT should not be performed before 3 weeks after treatment completion because of possible detection of residual nucleic acid not clinically relevant. [1]
Special Populations and Recurrent Infection
HIV Infection
- For women with HIV, metronidazole 500 mg orally 2 times/day for 7 days is recommended. [1]
- Rationale includes reduced effectiveness of single-dose metronidazole compared with 7-day multidose metronidazole in women with HIV and T. vaginalis infection. [1]
Pregnancy
- Symptomatic pregnant women should be tested and treated. [1]
Drug Resistance and Recurrent Trichomoniasis
- If treatment failure occurs in a woman after completing metronidazole 500 mg orally 2 times/day for 7 days and there is reexposure to an untreated partner, a repeat course of the same regimen is recommended. [1]
- If no reexposure has occurred after standard metronidazole 500 mg orally 2 times/day for 7 days, treatment is metronidazole or tinidazole 2 g once daily for 7 days. [1]
- If a man has persistent T. vaginalis after a single 2 g dose of metronidazole and there is reexposure to an untreated partner, he should be retreated with a single 2 g dose of metronidazole. [1]
- If a man has persistent infection without reexposure after a single 2 g dose, he should receive metronidazole 500 mg orally 2 times/day for 7 days. [1]
Common Pitfalls to Avoid
- Partner treatment omission is a major driver of reinfection. [1]
- Retesting before 3 weeks after treatment completion using NAAT can detect residual nucleic acid that is not clinically relevant. [1]
- Topical therapy with metronidazole gel is not recommended because of inadequate tissue levels and lower efficacy. [1]