What is the recommended treatment for a patient diagnosed with trichomoniasis?

Treatment of Trichomoniasis

First-Line Treatment Recommendation

The CDC recommends metronidazole 500 mg orally twice daily for 7 days as the preferred first-line treatment for trichomoniasis, achieving cure rates of 90-95%. 1

While both single-dose (2g) and 7-day regimens are CDC-approved, the most recent 2025 guidelines prioritize the 7-day regimen due to superior efficacy demonstrated in high-quality research. A randomized controlled trial of 623 women showed significantly lower treatment failure with 7-day dosing (11% failure) compared to single-dose therapy (19% failure), with a relative risk of 0.55 (p<0.0001). 2

Alternative First-Line Regimen

• Metronidazole 2g orally as a single dose remains an acceptable alternative, particularly when medication adherence is a concern, with cure rates of approximately 90-95%. 3, 4
• The single-dose regimen offers advantages of simplified administration and better compliance in select patients. 5

Critical Management Principles

All sexual partners must be treated simultaneously to prevent reinfection—this is mandatory, not optional. 3, 1, 4

• Patients must abstain from sexual activity until both they and their partners complete treatment and are asymptomatic. 3, 1, 4
• Failure to treat partners is the most common cause of recurrent infection. 3, 1
• Advise patients to avoid alcohol during treatment and for at least 24 hours after completion due to potential disulfiram-like reaction (nausea, vomiting, flushing, headache, abdominal cramps). 4

Treatment Failure Algorithm

For first treatment failure:

• Re-treat with metronidazole 500 mg orally twice daily for 7 days. 3, 1, 4

For second treatment failure:

• Administer metronidazole 2g orally once daily for 3-5 days. 3, 1, 4

For persistent failure:

• Exclude reinfection first (ensure partner treatment and sexual abstinence). 3
• Consult infectious disease specialist for susceptibility testing if reinfection has been excluded. 3, 4
• Consider desensitization if true metronidazole allergy exists, as effective alternatives are limited. 4

Alternative Agent: Tinidazole

• Tinidazole 2g orally as a single dose is FDA-approved for trichomoniasis with cure rates of 92-100% in clinical trials. 6
• Partners of infected patients should be treated simultaneously to prevent reinfection. 6
• Tinidazole demonstrates comparable efficacy to metronidazole in head-to-head trials. 7

Special Populations

Pregnancy:

• Metronidazole is contraindicated in the first trimester. 3, 1
• After the first trimester, treat with metronidazole 2g orally as a single dose. 3, 1
• Treatment is important as trichomoniasis is associated with premature rupture of membranes and preterm delivery. 3

HIV-infected patients:

• Use the same treatment regimens as HIV-negative patients. 1, 4

Follow-Up Recommendations

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

Critical Pitfall to Avoid

Topical metronidazole gel is NOT effective for trichomoniasis and should never be used—efficacy is less than 50%. 3, 1, 4

• Topical preparations fail to achieve therapeutic levels in the urethra and perivaginal glands. 1
• Clotrimazole vaginal tablets and other topical agents have cure rates of only 11-19% compared to 80% with oral metronidazole. 8