Treatment of Trichomoniasis
The first-line treatment for trichomoniasis is oral metronidazole 500 mg twice daily for 7 days, which is more effective than the single-dose regimen with cure rates of approximately 90-95%. 1, 2, 3
First-Line Treatment Options
- Metronidazole 500 mg orally twice daily for 7 days is the preferred regimen for trichomoniasis infection 1, 2
- An alternative regimen is metronidazole 2g orally in a single dose, which has slightly lower efficacy but may be preferred when medication adherence is a concern 1, 2, 4
- Tinidazole is also FDA-approved for trichomoniasis treatment and can be used as an alternative to metronidazole 5
Important Clinical Considerations
- Topical metronidazole gel is NOT effective for trichomoniasis (efficacy <50%) and should not be used 6, 1, 7
- Metronidazole can cause a disulfiram-like reaction when combined with alcohol, so patients should avoid alcohol during treatment and for at least 24 hours after completing therapy 1
- All sexual partners should be treated simultaneously to prevent reinfection, even if asymptomatic 1, 2, 4
- Patients should abstain from sexual activity until both they and their partners complete treatment and are asymptomatic 1, 2
Treatment Failure Management
- For first treatment failure, re-treat with metronidazole 500 mg twice daily for 7 days 6, 1, 2
- For repeated failure, administer metronidazole 2g once daily for 3-5 days 6, 1, 2
- If treatment continues to fail and reinfection has been excluded, consultation with an infectious disease specialist is recommended 6, 2
- Determining the susceptibility of T. vaginalis to metronidazole may be necessary in persistent cases 6
Special Populations
Pregnancy
- Metronidazole is contraindicated during the first trimester of pregnancy 2
- After the first trimester, pregnant women with symptomatic trichomoniasis can be treated with metronidazole 2g orally in a single dose 6, 2, 8
- Treatment is important as trichomoniasis has been associated with adverse pregnancy outcomes, including premature rupture of membranes and preterm delivery 2, 8
HIV Infection
- Patients with HIV infection should receive the same treatment regimen as HIV-negative individuals 6, 1, 2
Metronidazole Allergy
- For patients with immediate-type allergy to metronidazole, desensitization may be required as effective alternatives are limited 6, 1, 2
Follow-Up Recommendations
- Routine follow-up is unnecessary for patients who become asymptomatic after treatment 6, 1, 2
- If symptoms persist, patients should be re-evaluated for possible reinfection or resistant infection 1, 2
Evidence Comparison
Recent research has demonstrated that the 7-day regimen of metronidazole is more effective than the single-dose treatment. A randomized controlled trial found that patients in the 7-day-dose group were less likely to be T. vaginalis positive at test-of-cure than those in the single-dose group (11% vs 19%, relative risk 0.55) 3. This contradicts older studies that found similar efficacy between the regimens 9, 10.