What is the recommended treatment for trichomoniasis?

Treatment for Trichomoniasis

The preferred treatment for trichomoniasis is metronidazole 500 mg orally twice daily for 7 days, which achieves superior cure rates compared to single-dose therapy and should be used for all patients. 1, 2

First-Line Treatment Regimen

• Metronidazole 500 mg orally twice daily for 7 days is the CDC-recommended preferred regimen, achieving cure rates of 90-95% 1, 2, 3
• This multi-day regimen demonstrates significantly better efficacy than single-dose therapy, with an 8% absolute reduction in treatment failure (11% vs 19% failure rates) 4
• The single 2g dose of metronidazole, while FDA-approved and historically used, is now considered an alternative rather than preferred option due to higher failure rates 5, 3

Critical Partner Management

• All sexual partners must be treated simultaneously, regardless of symptoms or test results 1, 2, 6
• Patients must abstain from all sexual activity until both partners complete the full treatment course and are completely asymptomatic 1, 2, 6
• Failure to treat partners is the single most common cause of recurrent infection and apparent treatment failure 2

Special Population Considerations

Pregnancy

• Metronidazole is contraindicated during the first trimester 1, 2
• After the first trimester, use metronidazole 2g orally as a single dose (not the 7-day regimen, to minimize fetal exposure) 1, 2
• Treatment is important as trichomoniasis increases risk of premature rupture of membranes and preterm delivery 1

HIV-Infected Patients

• Use the same treatment regimens as HIV-negative patients (metronidazole 500 mg twice daily for 7 days) 1, 2, 6
• No dose adjustment or alternative regimen is needed 1, 2

Treatment Failure Algorithm

When treatment fails despite documented adherence and partner treatment:

1. First failure: Re-treat with metronidazole 500 mg twice daily for 7 days 1, 2, 6
2. Second failure: Administer metronidazole 2g once daily for 3-5 days 1, 2, 6
3. Persistent failure: Consult infectious disease specialist for possible resistance testing and desensitization protocols 1, 6

The MLC associated with metronidazole treatment failure is ≥50 μg/mL, and for tinidazole is ≥6.3 μg/mL 7

Alternative Agent: Tinidazole

• Tinidazole 2g orally as a single dose is FDA-approved and achieves equivalent cure rates (95-97.5%) to metronidazole 8, 9
• May be considered when adherence to multi-day regimens is problematic 6
• Has similar side effect profile to metronidazole 9

Critical Pitfalls to Avoid

• Never use topical metronidazole gel for trichomoniasis - it has <50% efficacy because it fails to achieve therapeutic levels in the urethra and perivaginal glands where the organism resides 2, 6
• Counsel patients to avoid all alcohol during treatment and for at least 24 hours after completion due to disulfiram-like reaction causing nausea, vomiting, flushing, and abdominal cramps 6
• Do not assume asymptomatic male partners are uninfected - they harbor the organism and must be treated to prevent reinfection 5, 3

Follow-Up Recommendations

• Routine follow-up is unnecessary for patients who become asymptomatic after treatment 1, 2, 6
• Re-evaluate only if symptoms persist, considering either reinfection from untreated partner or resistant infection 2, 6