Objective: This study was undertaken to investigate the efficacy of nonoxynol 9 suppositories in the treatment of vaginal trichomoniasis.
Study design: In this prospective comparison trial 46 women with documented motile trichomonads found on a wet preparation were randomly assigned to one of two treatment arms: (1) a single oral dose of 2 g metronidazole and (2) a single 150-mg nonoxynol 9 suppository placed intravaginally for 3 consecutive nights. Cure was determined by a repeated wet preparation examination. After its first year, the study was terminated because of the poor efficacy of the nonoxynol 9 suppositories.
Results: Results were available for 33 patients. Three of 17 patients treated with nonoxynol 9 had negative wet preparation results at retest (17.6% cure rate). All 16 patients treated with metronidazole had negative wet preparation results (100% cure rate). All women with nonoxynol 9 failures who were evaluated after treatment with 2 g metronidazole had negative wet preparation results.
Conclusion: Intravaginal nonoxynol 9 at the tested dose and by the tested method of delivery was not an effective cure for vaginal trichomoniasis.