Secnidazole: a treatment for trichomoniasis in adolescents and adults

ABSTRACT

Introduction

Single-dose 2-g oral secnidazole (SEC), newly approved by the U.S. Food and Drug administration (FDA) for treatment of trichomoniasis, is a potent 5-nitroimidazole with selective toxicity against various micro-organisms. It has been used internationally to treat trichomoniasis, bacterial vaginosis, and other infections for decades. Trichomoniasis is the most common non-viral sexually transmitted infection worldwide and is associated with significant morbidity. In comparison to the only other FDA-approved treatments for trichomoniasis in the United States – metronidazole and tinidazole – SEC has favorable pharmacokinetics, including a longer half-life and a lower minimal lethal concentration.

Areas covered

This work summarizes the chemistry and pharmacology of SEC and reviews the evidence on its efficacy, tolerability, and safety for the treatment of trichomoniasis.

Expert opinion

SEC is an efficacious, well tolerated, and safe treatment for patients aged ≥12 years with trichomoniasis. Single-dose administration makes it a favorable treatment option, especially in cases where adherence to multi-dose treatment regimens may be low.

KEYWORDS:

• Trichomoniasis
• Trichomonas vaginalis
• secnidazole
• 5-nitroimidazoles
• metronidazole
• tinidazole
• sexually transmitted infections

Acknowledgments

Elizabeth Sarkar, Jespersen & Associates, LLC for communications with authors, coordination of reference retrieval and illustration of molecular structures.

Article highlights

• In the United States, trichomoniasis affects 2.1% of women and 0.5% of men aged 18–59 years and disproportionately affects African Americans [1].

• Trichomoniasis is associated with significant adverse outcomes if not treated promptly and appropriately. In women, trichomoniasis can cause vaginitis, cervicitis, pelvic inflammatory disease [2-4], cervical cancer [5], infertility [6], and adverse birth outcomes, including preterm birth, premature rupture of membranes, and low birth weight [7,8]. In men, trichomoniasis can result in non-gonococcal urethritis, epididymitis, prostatitis, and infertility [1,9]. Infection can increase the risk for human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs; chlamydia, gonorrhea, herpes simplex virus, and syphilis) in both sexes [1].

• Coexistence of bacterial vaginosis (BV) and T. vaginalis is very common, with coinfection rates of 60–80% [10]. The risk of acquiring trichomoniasis is two-fold higher among women with BV compared to women without BV [11].

• The Centers for Disease Control and Prevention (CDC) recommend diagnostic testing for T. vaginalis for all women seeking care for vaginal discharge. Screening is recommended annually for HIV-infected women and can be considered for persons receiving care in high-prevalence settings (e.g. STD clinics and correctional facilities) and for asymptomatic women at high risk for infection (e.g. multiple sexual partners, transactional sex, drug misuse, and/or a history of STIs or incarceration) [1].

• Updated guidelines now recommend multi-dose metronidazole (MTZ) 500 mg orally twice daily for 7 days for the treatment of all women with T. vaginalis, although a single 2-g dose of oral MTZ remains the recommended treatment for men. This is the first time recommended treatment regimens for a STI differ based on gender, which may present unique challenges.

• Updated guidelines have removed the recommendation to refrain from alcohol use while taking 5-nitroimidazoles due to lack of data on disulfiram-like reaction [1].

• Retest all sexually active T. vaginalis-infected women within 3 months of treatment due to high rates of recurrence. If retesting at 3 months is not possible, providers can retest whenever women next seek medical care [1].

A single 2-g dose of secnidazole is newly approved by the U.S. Food and Drug Administration for the treatment of trichomoniasis in adult women and men and is the only single-dose oral treatment option for both BV and trichomoniasis.

Declaration of interest

C Muzny has received research grant support from Lupin Pharmaceuticals, Gilead Sciences, Inc, and Abbott Molecular, is a consultant for Lupin Pharmaceuticals, PhagoMed, and BioFire Diagnostics, and has received honoraria from Elsevier, Abbott Molecular, Cepheid, Becton Dickinson, Roche Diagnostics, and Lupin. O Van Gerwen has received research grant support from Gilead Sciences, Inc and Abbott Molecular. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Scientific accuracy review

Lupin Pharmaceuticals provided a scientific accuracy review at the request of the journal editor.

Additional information

Funding

Medical writing assistance was provided by Linda Goldstein, PhD, CMPP, of The Write Source MSC, LLC and funded by Lupin Pharmaceuticals. Lupin Pharmaceuticals had no other role in the design and development of the content, writing, or reviewing of this manuscript. The opinions in this article are solely those of the authors.