The antiprotozoal agent tinidazole has been approved in the United States for treating trichomoniasis, providing a new therapeutic option for recurrent or resistant cases of the vaginal infection.
The drug "is going to make a lot of difference in terms of treating those unusual patients who really don't respond well to [metronidazole] therapy" and have recurrent or more resistant trichomoniasis, said Sharon Hillier, Ph.D., director of reproductive infectious disease research and the Center for Excellence in Women's Health, Magee-Women's Hospital, Pittsburgh.
Tinidazole, an antiprotozoal agent that has been used in other countries for more than 25 years, also received Food and Drug Administration approval for treating giardiasis, intestinal amebiasis, and amebic liver abscess.
Tinidazole is being marketed by Presutti Laboratories Inc. under the trade name Tindamax. Tinidazole had been available to U.S. clinicians only on a compassionateuse basis.
The recommended dosage of tinidazole for trichomoniasis is a single 2-g oral dose for the patient and her sexual partner or partners. This dose for trichomoniasis has been studied in 34 published reports with a combined total of more than 2,800 patients.
Reported cure rates have ranged from 80% to 100% in women and 83% to 100% in men, according to the U.S. product label.
Tinidazole has an extensive safety record outside the United States, including in the United Kingdom, where it has been used to treat bacterial vaginosis and trichomoniasis for about 20 years. It's also known to effectively treat some women with trichomoniasis that is resistant to metronidazole. Dr. Hillier said in an interview.
According to the Centers for Disease Control and Prevention's Sexually Transmitted Diseases Treatment Guidelines, metronidazole is the recommended treatment for trichomoniasis. Clinicians who treat vaginal infections typically see one or two patients each year who do not respond to metronidazole therapy, she said.
Dr. Hillier expects that there will be a good deal of interest in evaluating Tindamax as a treatment for bacterial vaginosis and as a primary treatment for trichomoniasis in postmarketing studies. Induction of resistance does not appear to be a problem with this drug, she said.
Like metronidazole, tinidazole has been used widely in adolescent populations in the United Kingdom, so Dr. Hillier expects it will prove to be useful in sexually active teenagers in the United States, although the label says that safety and effectiveness in pediatric patients have not been established.
Tinidazole is chemically related to metronidazole (both are 5-nitroimidazoles), so it may interact with drugs that are known to interact with metronidazole, including warfarin, lithium, and phenytoin. Alcohol should be avoided during treatment and for 3 days after discontinuing the drug, and tinidazole should not be used during the first trimester of pregnancy, according to the U.S. product label.
Dr. Hillier said she has no ties to Presutti Laboratories Inc.
BY ELIZABETH MECHCATIE
COPYRIGHT 2004 International Medical News Group
COPYRIGHT 2004 Gale Group