What is the recommended treatment for trichomoniasis?

Treatment for Trichomonas

The recommended first-line treatment for trichomoniasis is metronidazole 2 g orally in a single dose. 1

Primary Treatment Options

First-Line Regimen

• Metronidazole 2 g orally in a single dose 1
  • FDA-approved for treatment of symptomatic and asymptomatic trichomoniasis 2
  • Cure rates of approximately 90-95% in randomized clinical trials 1

Alternative Regimen

• Metronidazole 500 mg orally twice daily for 7 days 1
  • Recent evidence suggests this regimen may be more effective than the single-dose treatment
  • A 2018 randomized controlled trial found that the 7-day regimen had a significantly lower treatment failure rate (11% vs 19%) compared to the single-dose regimen 3

Management Algorithm

1. Diagnosis confirmation

   • Wet mount microscopy (60-70% sensitivity) or culture (more sensitive) 4
   • Nucleic acid amplification tests may be available from commercial laboratories 1

2. Treatment selection

   • For non-pregnant patients: Metronidazole 2 g single dose OR metronidazole 500 mg twice daily for 7 days
   • Consider 7-day regimen for patients with higher risk of treatment failure 3

3. Partner treatment

   • Treat all sexual partners simultaneously to prevent reinfection 1, 2
   • Partners should be treated even if asymptomatic 2

4. Follow-up

   • Routine follow-up is unnecessary for patients who become asymptomatic after treatment 1
   • Advise patients to abstain from sexual activity until both patient and partner(s) complete treatment and are asymptomatic 1

Treatment Failure Management

If treatment failure occurs with the initial regimen:

1. First failure: Re-treat with metronidazole 500 mg twice daily for 7 days 1
2. Second failure: Treat with metronidazole 2 g once daily for 3-5 days 1
3. Persistent failure: Consult with specialist and consider susceptibility testing of T. vaginalis to metronidazole 1
   • Resistant strains have been identified with minimal lethal concentration ≥50 μg/mL for metronidazole 5

Special Considerations

Pregnancy

• Metronidazole 2 g single dose can be used after the first trimester 1
• More recent guidelines indicate metronidazole can be used throughout pregnancy 1
• Multiple studies and meta-analyses have not demonstrated consistent teratogenic or mutagenic effects 1

HIV Infection

• Patients with HIV should receive the same treatment regimen as HIV-negative patients 1

Allergy or Intolerance

• Patients with immediate-type allergy to metronidazole can be managed by desensitization 1
• No effective alternatives to nitroimidazoles are currently available 1
• Topical therapy has low efficacy (<50%) 1

Important Caveats

• Metronidazole gel is not recommended for trichomoniasis treatment despite its approval for bacterial vaginosis, as it has <50% efficacy for trichomoniasis 1
• Tinidazole is FDA-approved for trichomoniasis 6 but was not included in the primary treatment recommendations in the guidelines reviewed
• Alcohol should be avoided during treatment with metronidazole and for at least 24-48 hours afterward due to potential disulfiram-like reaction