Treatment of Trichomoniasis with Metronidazole
Metronidazole 2g as a single oral dose is an effective FDA-approved treatment option for trichomoniasis, though the 7-day regimen (500mg twice daily for 7 days) has demonstrated higher cure rates in recent research. 1, 2
Treatment Options for Trichomoniasis
First-line Treatment Options:
- Single-dose regimen: 2g metronidazole orally in a single dose 2
- 7-day regimen: 500mg metronidazole orally twice daily for 7 days 1
Efficacy Comparison:
- Recent evidence suggests the 7-day regimen may be more effective than the single-dose treatment
- A 2018 randomized controlled trial found that patients receiving the 7-day course were less likely to test positive at follow-up (11%) compared to those receiving the single dose (19%) 3
- However, earlier studies from the 1980s and 1990s showed comparable efficacy between the two regimens 4, 5
Clinical Decision Making
When to Consider Single-Dose Treatment:
- When compliance is a concern
- For patients who cannot be relied upon to complete the 7-day regimen
- When supervised administration is possible 2
- When treating sexual partners 1
When to Consider 7-Day Treatment:
- To minimize reinfection by providing longer protection
- When higher cure rates are prioritized
- For patients who can reliably complete the full course 1, 3
Important Considerations
Patient Education:
- Advise patients to avoid alcohol during treatment and for 24 hours afterward to prevent disulfiram-like reactions 1
- Inform patients about potential side effects: nausea (most common), headache, and vomiting 3
Partner Management:
- All sexual partners should be treated simultaneously to prevent reinfection 1
- Partners who had sexual contact within 30 days of symptom onset should be evaluated and treated 1
Special Populations:
- Pregnancy: Metronidazole is contraindicated in the first trimester 1
- After first trimester, the 7-day regimen is preferred over single-dose treatment, as higher serum levels from single-dose therapy may reach fetal circulation 1, 2
- Elderly patients: Pharmacokinetics may be altered; monitoring of serum levels may be necessary 2
Follow-up:
- Routine follow-up is unnecessary for asymptomatic patients after treatment 1
- Test-of-cure is recommended for persistent symptoms, suspected reinfection, or questionable compliance 1
- Patients should be retested 3 months after treatment 1
- For persistent or recurrent infection, consider retreatment with initial regimen if compliance was poor or re-exposure occurred 1