FDA Approves Secnidazole (Solosec) Additional Indication for Trichomoniasis

By Jessica Pyhtila, PharmD, BCGP, BCPS

The FDA recently expanded approval for secnidazole to include trichomoniasis in adults. The drug had previously been approved for bacterial vaginosis in women.

Trichomoniasis, caused by the protozoan Trichomonas vaginalis, is the most common nonviral STD in the world, often afflicting women more than men. It commonly occurs with bacterial vaginosis, with coinfection rates up to 80%. The 5-nitroimidazole drugs — metronidazole, tinidazole, and now secnidazole — are the only proven curative treatments for the condition.

Secnidazole comes as a single 2-gram packet of granules. It should be administered once orally, and mixed with applesauce, yogurt or pudding. The product should be consumed within 30 minutes without chewing or crunching the granules. Although the patient may drink a glass of water to aid in swallowing, the drug is not dissolvable in liquid and should not be directly added to liquid for this reason.

Common adverse effects linked to secnidazole include vulvo-vaginal candidiasis, headache, nausea, dysgeusia, vomiting, diarrhea, abdominal pain, and vulvovaginal pruritus. Chronic use of the agent should be avoided as carcinogenicity has been observed in rodents chronically treated with the drug, although it is unclear if carcinogenicity extends to humans.

Alcohol should be avoided for 2 days after taking the drug due to a disulfiram-like reaction. Effects may include nausea, vomiting, diarrhea, abdominal pain, dizziness, and headache.

Secnidazole may be safely administered with oral contraceptives as there is no drug interaction between the agents. Animal studies showed no adverse developmental outcomes during pregnancy, although limited data are available in humans. However, due to to the potential carcinogenicity of the agent, breastfeeding should be paused for 96 hours after administration of secnidazole. Any pumped milk should be discarded during this time.

References:

Sobel, Jack D; et al. “Mixed vaginitis-more than coinfection and with therapeutic implications.” Current Infectious Disease Reports, April 2013. Retrieved from: https://pubmed.ncbi.nlm.nih.gov/23354954/

Food and Drug Administration. “Solosec.” June 2021. Retrieved from: https://www.accessdata.fda.gov/drugsatfda_docs/label/2021/209363s015lbl.pdf