The Food and Drug Administration has expanded the approval of Solosec® (secnidazole) to include treatment of trichomoniasis caused by Trichomonas vaginalis in adults. Previously, the nitroimidazole antimicrobial agent had only been approved for bacterial vaginosis.

The approval was based on data from a double-blind, placebo-controlled phase 3 study that evaluated the efficacy and safety of secnidazole in 147 adult female patients with trichomoniasis. Patients were randomly assigned to receive either a 2g single oral dose of secnidazole granules or placebo at visit 1 (baseline). After 6 to 12 days, patients were evaluated at the test of cure (TOC) visit. The primary end point was microbiological cure at the TOC visit.

Treatment with secnidazole resulted in clinically and statistically significant microbiological cure, defined as a negative Trichomonas vaginalis culture, vs placebo at the TOC visit (P <.001). The cure rate was 92.2% (n=59/64) for secnidazole vs 1.5% (n=1/67) for placebo in the modified intent-to-treat population, which included patients who tested positive for T. vaginalis and negative for gonorrhea and chlamydia at baseline. In the per-protocol population, the cure rate was 94.9% (n=56/59) for secnidazole vs 1.7% (n=1/60) for placebo (P <.001). The most common adverse reaction observed in the clinical trial was vulvovaginal candidiasis.

Approval was also granted for treatment in men based on 4 open-label trials, a comparative study with metronidazole and ornidazole, and 3 single-arm studies (in both males and females). Cure rates were reported to range from 91.7% (n=165/180) to 100% (n=30/30) at time points ranging from 2 days to 20 days. Spontaneous resolution during a mean follow-up of 16 ± 12 days was noted in 36% (n=5/14) (95% CI, 12.864.9) of untreated men.

The recommended dosage of Solosec for trichomoniasis is a single 2-gram packet of granules taken once orally. Since trichomoniasis is a sexually transmitted disease, sexual partners should be treated with the same dose and at the same time.

“The FDA’s approval for the additional indication for Solosec to treat trichomoniasis builds upon our commitment to support women’s health and provides health care professionals with an option to treat patients with trichomoniasis and bacterial vaginosis,” said Jon Stelzmiller, President – Specialty, Lupin Pharmaceuticals, Inc. “Having a treatment option for both trichomoniasis and BV that provides a complete course of therapy in a single dose will help address gaps in care related to adherence, and therefore, may reduce risk factors associated with trichomoniasis or BV, such as pelvic inflammatory disease (PID) and other STIs.”

Solosec is supplied as oral granules in single 2g unit-of-use child-resistant packets.


  1. Lupin announces FDA approval of supplemental new drug application for Solosec (secnidazole) for the treatment of trichomoniasis. [press release]. Mumbai, India and Baltimore, MD: Lupin Pharmaceuticals, Inc; July 1, 2021.
  2. Solosec [package insert]. Mumbai, India and Baltimore, MD: Lupin Pharmaceuticals, Inc; 2021.