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

Treatment of Trichomoniasis and Test of Cure

For patients diagnosed with trichomoniasis, metronidazole 2g orally in a single dose is the recommended first-line treatment, with metronidazole 500mg twice daily for 7 days as an alternative regimen. 1

First-Line Treatment Options

• Preferred regimen: Metronidazole 2g orally in a single dose 1, 2

  • Cure rates approximately 90-95% when sexual partners are also treated 1
  • FDA-approved for both symptomatic and asymptomatic trichomoniasis 2

• Alternative regimen: Metronidazole 500mg twice daily for 7 days 1, 3

  • May be more effective than single-dose therapy according to recent research
  • A 2018 randomized controlled trial showed that the 7-day regimen had a significantly lower treatment failure rate (11%) compared to single-dose therapy (19%) 4

Partner Treatment

• Sexual partners must be treated simultaneously to prevent reinfection 1, 2
• Trichomoniasis is a sexually transmitted disease with potentially serious sequelae 2
• Partners should receive the same treatment regimen as the index case 1

Test of Cure

• Routine test-of-cure is recommended in cases where:

  • Symptoms persist
  • Reinfection is suspected
  • Treatment compliance is questionable 1

• Patients should be retested 3 months after treatment, regardless of whether they believe their sex partners were treated 1

Management of Treatment Failure

If initial treatment fails:

1. Retreat with metronidazole 500mg twice daily for 7 days 1, 3
2. For persistent infection, administer metronidazole 2g once daily for 3-5 days 1, 3
3. Consider tinidazole as an alternative treatment for resistant cases 5

Special Considerations

• Pregnancy: Metronidazole is contraindicated in the first trimester but can be used after the first trimester (2g single dose) 1
• HIV infection: Patients with HIV should receive the same treatment regimen as HIV-negative patients 1, 3
• Metronidazole allergy: Options are limited; desensitization may be necessary 1

Important Caveats

• Avoid topical therapy: The CDC recommends against topical vaginal therapy due to low efficacy (<50% compared to oral preparations) 1
• Avoid sexual activity: Patients should avoid sexual activity until both they and their partners complete treatment and are asymptomatic 1
• Common side effects: Nausea (23%), headache (7%), and vomiting (4%) are common with metronidazole treatment 4

Diagnostic Methods

For accurate diagnosis and test of cure, the following methods can be used:

• Wet mount microscopy (60-70% sensitivity)
• Culture (most sensitive commercially available method)
• Nucleic Acid Amplification Tests (NAATs) - preferred when available 1

Following these evidence-based guidelines will ensure effective treatment of trichomoniasis and minimize the risk of reinfection or persistent infection.