Tinidazole therapy for metronidazole-resistant vaginal trichomoniasis

Treatment of patients with metronidazole-refractory vaginal trichomoniasis constitutes a major therapeutic challenge, and treatment options are extremely limited. Although the majority of patients infected with trichomonads, who demonstrate reduced in vitro susceptibility to metronidazole, respond to high-dose but poorly tolerated regimens of metronidazole, clinical failure is by no means uncommon. We report a cure rate of 22 (92%) of 24 patients with refractory trichomoniasis treated with high doses of oral and vaginal tinidazole. This series included 15 cases with increased in vitro minimal lethal concentration values of metronidazole. Tinidazole, despite the high doses used, was extremely well tolerated, with few side effects. Topical paromomycin was effective in 7 (58%) of 12 patients treated, but frequent local vulvovaginal adverse reactions precluded extensive use. Widespread reports of metronidazole resistance and limited treatment options emphasize the need for additional trichomonacidal agents.