What is the recommended treatment for trichomoniasis?

Treatment for Trichomoniasis

The preferred first-line treatment for trichomoniasis is metronidazole 500 mg orally twice daily for 7 days, which achieves superior cure rates (89%) compared to single-dose therapy (81%) and should be used for all patients regardless of sex. 1, 2

First-Line Treatment Regimens

Metronidazole 500 mg orally twice daily for 7 days is the preferred regimen, with cure rates of approximately 90-95% 1. This multi-day regimen significantly outperforms single-dose therapy, reducing treatment failure by 45% (relative risk 0.55,95% CI 0.34-0.70; p<0.0001) 2.

Alternative Regimen

• Metronidazole 2 g orally as a single dose can be used when adherence to a 7-day regimen is uncertain, though it has lower efficacy (81% cure rate versus 89% for 7-day therapy) 3, 2
• Tinidazole 2 g orally as a single dose is FDA-approved and equally effective as single-dose metronidazole (95% versus 97.5% cure rates), but shares the same limitations of single-dose therapy 4, 5

Critical Medication Warnings

• Patients must completely avoid all alcohol during treatment and for at least 24 hours after the last dose to prevent severe disulfiram-like reactions (nausea, vomiting, flushing, headache, abdominal cramps) 3, 6
• Topical metronidazole gel is NOT effective for trichomoniasis (efficacy <50%) and should never be used 7, 3

Management of Sexual Partners

All sexual partners must be treated simultaneously, even if asymptomatic, to prevent reinfection 1, 3, 8. The organism can be difficult to isolate in asymptomatic male carriers, so negative cultures cannot be relied upon to exclude infection 7, 8.

• Patients should abstain from sexual activity until both they and all partners have completed treatment and are asymptomatic 1, 3

Treatment Failure Management

Treatment failure occurs in an estimated 159,000+ cases annually in the US, often due to decreased drug susceptibility 9.

For first treatment failure:

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

For second treatment failure:

• Administer metronidazole 2 g once daily for 3-5 days 7, 1, 3

For persistent failure after high-dose therapy:

• Consult an infectious disease specialist 1, 3
• Consider susceptibility testing (metronidazole MLC ≥50 μg/mL indicates resistance; tinidazole MLC ≥6.3 μg/mL indicates resistance) 9
• CDC consultation available at 770-488-4115 7
• Alternative therapies with limited evidence include high-dose tinidazole combined with intravaginal paromomycin cream, intravaginal boric acid, or intravaginal metronidazole/miconazole 10

Special Populations

Pregnancy

• Symptomatic pregnant women should be treated with metronidazole 2 g orally as a single dose after the first trimester 1
• Multiple studies and meta-analyses have not demonstrated teratogenic or mutagenic effects with metronidazole use during pregnancy 7
• Trichomoniasis is associated with premature rupture of membranes, preterm delivery, and low birthweight 7, 1
• Treatment of asymptomatic trichomoniasis during pregnancy has not been shown to reduce adverse pregnancy outcomes 7

HIV Infection

• Use the same treatment regimens as for HIV-negative patients (metronidazole 500 mg twice daily for 7 days preferred) 7, 1, 3

Metronidazole Allergy

• Patients with immediate-type allergy to metronidazole may require desensitization 7, 1, 3
• Topical therapies have poor cure rates (<50%) and are not recommended 7
• Effective alternatives to nitroimidazoles are extremely limited 1

Follow-Up Recommendations

• Routine follow-up is unnecessary for patients who become asymptomatic after treatment 7, 1, 3
• If symptoms persist, evaluate for reinfection (most common cause) or resistant infection 3
• Bacterial vaginosis does not significantly modify treatment efficacy and should not alter the treatment approach 2