Where do tinidazole and secnidazole fit in with the treatment of trichomoniasis?

Abstract

T richomonas vaginalis is the most prevalent nonviral sexually transmitted infection (STI) worldwide, 1 affecting ~3.7 million individuals in the United States. 2 The prevalence is estimated to be 0.5% in men and 2.1% in women; rates are significantly higher in African American women (9.6%) versus Hispanic women (1.4%) and non-Hispanic White women (0.8%). 3,4 The true US prevalence is not known, as T. vaginalis is not reportable, and screening is only recommended in HIV-infected women. 5 Trichomoniasis is associated with multiple adverse health outcomes in women, including vaginitis, cervicitis, 6 cervical cancer, 7 pelvic inflammatory disease, 8,9 and adverse birth outcomes. 10,11 In men, it is associated with nongonococcal urethritis, 12,13 epididymitis, 14 prostatitis, and infertility. 15,16 It also is associated with HIVand other STIs in both sexes. 5,6,17 Despite its high prevalence and adverse outcomes, the significance of trichomoniasis is underappreciated in the medical community. [18][19][20] The 5-nitroimidazoles, including metronidazole (MTZ), tinidazole (TDZ), and secnidazole (SEC), are the only class of antimicrobial agents with confirmed effectiveness against T. vaginalis. 21 Until recently, the Centers for Disease Control and Prevention (CDC) STI Treatment Guidelines for trichomoniasis recommended a single 2-g dose of oral MTZ for HIV-negative women and men or, alternatively, a single 2-g dose of oral TDZ for women and men; multidose oral MTZ (500 mg twice daily for 7 days) was recommended for HIV-infected women. 5 In 2021, the CDC changed their treatment recommendation for all women with T. vaginalis to multidose oral MTZ, with single-dose 2-g oral TDZ remaining as an alternate. 5 This was in response to a randomized controlled trial (RCT) that found multidose oral MTZ to be superior to single-dose oral MTZ in HIV-negative women. 22 The American College of Obstetricians and Gynecologists updated their 2020 Clinical Management Guidelines in the same manner. 5,6 In contrast, a single 2-g dose of oral MTZ remains the recommended treatment for T. vaginalis-infected men, with a single 2-g dose of oral TDZ as an alternative. 5 Secnidazole, a next-generation 5-nitroimidazole with a longer half-life than MTZ or TDZ, 21 received Food and Drug Administration (FDA) approval for trichomoniasis in women, men,