What is the recommended treatment for trichomoniasis?

Treatment for Trichomoniasis

Recommended First-Line Treatment

The preferred treatment for trichomoniasis is metronidazole 500 mg orally twice daily for 7 days, which achieves superior cure rates of 90-95% compared to single-dose therapy. 1, 2

The CDC has shifted its recommendation from single-dose to multi-day therapy based on evidence demonstrating significantly better outcomes. A 2018 randomized controlled trial demonstrated that 7-day metronidazole resulted in only 11% treatment failure compared to 19% failure with single-dose therapy (relative risk 0.55, p<0.0001). 3

Alternative Regimens

• Metronidazole 2 g orally as a single dose remains an acceptable alternative when adherence to multi-day therapy is a concern, 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 (95% vs 97.5% cure rates) 6, 7

Critical Management Principles

Partner Treatment (Essential to Prevent Reinfection)

• All sexual partners must be treated simultaneously, as failure to treat partners is the most common cause of recurrent infection 1, 2, 5
• Patients must abstain from sexual activity until both partners complete treatment and are asymptomatic 1, 2, 5
• Asymptomatic male partners should be treated even with negative cultures, as the organism is difficult to isolate from male carriers 4

What NOT to Do (Common Pitfall)

Never use topical metronidazole gel for trichomoniasis - it has efficacy <50% because it fails to achieve therapeutic levels in the urethra and perivaginal glands where the organism resides 2, 5

Special Populations

Pregnancy

• Metronidazole is contraindicated in the first trimester 1, 2
• After the first trimester: metronidazole 2 g orally as a single dose is recommended 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 patients 1, 2, 5

Metronidazole Allergy

• Effective alternatives are not readily available 1
• Patients with immediate-type allergy may require desensitization 1

Treatment Failure Algorithm

First failure: Re-treat with metronidazole 500 mg twice daily for 7 days 1, 2, 5

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

Persistent failure:

• Exclude reinfection first (most common cause) 5
• Consider drug resistance - metronidazole MLC ≥50 μg/mL or tinidazole MLC ≥6.3 μg/mL indicates resistance 8
• Consult infectious disease specialist 1, 5
• Alternative therapies for resistant cases include high-dose tinidazole with intravaginal paromomycin cream, intravaginal boric acid, or intravaginal metronidazole/miconazole combination 9

Follow-Up

• Routine follow-up is unnecessary for patients who become asymptomatic after treatment 1, 2, 5
• Re-evaluate only if symptoms persist, considering reinfection or resistant infection 2, 5

Important Patient Counseling

• Avoid alcohol during treatment and for at least 24 hours after completing metronidazole to prevent disulfiram-like reaction (nausea, vomiting, flushing, headache, abdominal cramps) 5
• Most common side effects are nausea (23%), headache (7%), and vomiting (4%) 3