What is the recommended treatment for Trichomonas infections?

Treatment of Trichomonas Infections

Metronidazole 500mg orally twice daily for 7 days is the first-line treatment for Trichomonas infections, as recommended by the CDC. 1

First-Line Treatment Options

• Metronidazole regimen:

  • Dose: 500mg orally
  • Frequency: Twice daily
  • Duration: 7 days
  • FDA-approved indication: Treatment of symptomatic and asymptomatic trichomoniasis 2

• Alternative treatment (for metronidazole allergy):

  • Tinidazole 2g orally in a single dose 1, 3
  • FDA-approved specifically for treatment of trichomoniasis caused by Trichomonas vaginalis 3

Evidence Supporting 7-Day Treatment Over Single Dose

While single-dose metronidazole (2g) has historically been used, more recent evidence supports the 7-day regimen as more effective:

• A randomized controlled trial found that patients treated with the 7-day metronidazole regimen were less likely to have positive T. vaginalis tests at follow-up compared to those who received single-dose therapy (11% vs 19%) 4
• The 7-day course demonstrated a relative risk of 0.55 (95% CI 0.34-0.70; p<0.0001) for treatment failure compared to single-dose therapy 4

Diagnostic Considerations

Before initiating treatment, confirm diagnosis through one of these methods:

• Nucleic acid amplification tests (NAATs) - preferred method due to highest sensitivity 1
• Culture - most sensitive commercially available method 1
• Wet mount microscopy - limited sensitivity (60-70%) 1

Partner Treatment and Prevention

• All recent sexual partners (within 60 days) should be evaluated, tested, and treated 1
• Patients should abstain from sexual intercourse until they and their partners have completed treatment 1
• Simultaneous treatment of partners is essential to prevent reinfection 3, 2

Important Precautions

• Patients should avoid alcohol during treatment and for 24-48 hours afterward to prevent disulfiram-like reactions 1
• Avoid prolonged courses of metronidazole to minimize risk of cumulative and potentially irreversible neurotoxicity 1
• Metronidazole is contraindicated in the first trimester of pregnancy 1

Treatment Monitoring

• Improvement in symptoms should be seen within 72 hours of starting treatment 1
• If no improvement is observed, consider an alternative regimen and reassess the diagnosis 1
• Routine test-of-cure is not generally recommended, but consider retesting all patients 3 months after treatment due to high rates of reinfection 1

Failed Treatment Approaches

• Intravaginal metronidazole gel (0.75%) is not effective as a single agent for treating trichomoniasis, with only 44% cure rate compared to 100% with oral metronidazole in a pilot study 5
• Intravaginal metronidazole combined with miconazole has shown some promise but is not currently recommended as first-line therapy 6