BACKGROUND AND PURPOSE:

• Secnidazole: 5-nitroimidazole antibiotic with a longer half-life than metronidazole or tinidazole | Single dose | Oral granules
• Muzny et al. (Clinical Infectious Diseases, 2021) assessed the efficacy and safety of secnidazole in women with trichomoniasis

METHODS:

• Phase 3, randomized, double-blind, placebo-controlled trial
• Participants
  • Women with trichomoniasis confirmed by a positive T. vaginalis culture
• Interventions
  • Single-dose oral secnidazole 2g
  • Placebo
• Study design
  • At the test of cure visit at 6 to 12 days, based on positive T. vaginalis culture, participants were given the opposite treatment
    • Infection resolved: Discharged from study
    • Infection still present: Returned for visit 7 to 12 days later for assessment and treatment
    • Additional visits and treatments based on care provider discretion
• Power analysis
  • Assumptions: Microbiological cure rates of 75% (secnidazole) and 40% (placebo)
• 95% power | α=0.05 level of significance
• Sample size: 100 patients (50 patients/group)
• Analysis was by modified intent-to-treat
• Primary outcome
  • Microbiological test of cure (TOC) by culture 6 to 12 days after dosing

RESULTS:

• 131 patients
  • Secnidazole: 64 patients
  • Placebo: 67 patients
• Cure rates were significantly higher in the secnidazole group (modified intent-to-treat population)
  • Secnidazole: 92.2% (95% CI, 82.7 to 97.4)
  • Placebo: 1.5% (95% CI, 0.0 to 8.0)
• Rates were similar in the per-protocol population
• Cure rates in subpopulations
  • Women with HIV: 100% (4/4 women)
  • Women with bacterial vaginosis: 95.2% (20/21 women)
• Most frequently reported adverse events with secnidazole
  • Vulvovaginal candidiasis: 2.7%
  • Nausea: 2.7%
• No serious adverse effects were reported

CONCLUSION:

• For women with trichomoniasis, a single dose of 2g secnidazole was associated with a higher cure rate vs placebo
  • These higher cure rates were consistent in women with HIV and bacterial vaginosis
• The medication as well tolerated, with few adverse effects reported
• The authors note that pregnant women were not included in the study, however

Future studies should be considered in pregnant women and those with persistent T. vaginalis infection 

Learn More – Primary Sources:

Efficacy and Safety of Single Oral Dosing of Secnidazole for Trichomoniasis in Women: Results of a Phase 3, Randomized, Double-Blind, Placebo-Controlled, Delayed-Treatment Study

Related ObG Topics:

Trichomoniasis: CDC Diagnosis and Treatment Guidelines

FDA Approves Secnidazole: Single-Dose Oral Treatment for BV

Diagnosing Vaginitis – Why the Office Visit Still Matters

STI Screening in Pregnancy: CDC Recommendations

Sexually Transmitted Diseases and Partner Notification