What is the recommended treatment for trichomoniasis?

Treatment for Trichomoniasis

Recommended First-Line Treatment

Metronidazole 500 mg orally twice daily for 7 days is the preferred treatment regimen for trichomoniasis, achieving cure rates of 90-95%. 1, 2

This multi-day regimen is superior to single-dose therapy based on the most recent high-quality evidence. A 2018 randomized controlled trial of 623 women demonstrated that the 7-day regimen resulted in significantly fewer treatment failures compared to single-dose therapy (11% vs 19% failure rate, p<0.0001). 3

Alternative Regimens

• Single-dose option: Metronidazole 2 g orally as a single dose can be used, particularly for males or when adherence to multi-day therapy is uncertain, though it has lower efficacy 4, 5
• Tinidazole: 2 g orally as a single dose is FDA-approved and demonstrates equivalent efficacy to single-dose metronidazole 6, 7
• Secnidazole: 2 g orally as a single dose is newly FDA-approved with favorable pharmacokinetics including longer half-life 8

Critical Management Principles

Partner Treatment (Essential to Prevent Reinfection)

• All sexual partners must be treated simultaneously 1, 2, 5
• Patients must abstain from sexual activity until both partners complete treatment and are asymptomatic 1, 2
• Failure to treat partners is the most common cause of recurrent infection 2
• Treat asymptomatic male partners even with negative cultures, as the organism is difficult to isolate from male carriers 5

Alcohol Avoidance

• Patients must avoid alcohol during treatment and for at least 24 hours after completing metronidazole therapy 4
• Metronidazole causes a disulfiram-like reaction with alcohol (nausea, vomiting, flushing, headache, abdominal cramps) 4

Special Populations

Pregnancy

• Metronidazole is contraindicated in the first trimester 1, 2
• After the first trimester: Use metronidazole 2 g orally as a single dose 1, 2
• Treatment is important as trichomoniasis is associated with premature rupture of membranes and preterm delivery 1

HIV-Infected Patients

• Use the same treatment regimens as HIV-negative individuals 1, 2, 4

Metronidazole Allergy

• Effective alternatives are limited 1
• Patients with immediate-type allergy may require desensitization 1, 4

Treatment Failure Algorithm

First failure: Re-treat with metronidazole 500 mg twice daily for 7 days 1, 2, 4

Second failure: Administer metronidazole 2 g once daily for 3-5 days 1, 2, 4

Continued failure: After excluding reinfection, consult an infectious disease specialist 1, 4

Follow-Up Recommendations

• Routine follow-up is unnecessary for patients who become asymptomatic after treatment 1, 2, 4
• Re-evaluate only if symptoms persist, considering reinfection or resistant infection 2, 4

Critical Pitfall to Avoid

Never use topical metronidazole gel for trichomoniasis 2, 4

• Topical metronidazole has efficacy <50% for trichomoniasis 2, 4
• It fails to achieve therapeutic levels in the urethra and perivaginal glands 2
• This is a common error that leads to treatment failure 2