NEW YORK (Reuters Health) – Tinidazole is no more effective than metronidazole in bacterial vaginosis. New treatments are still needed, researchers report in an on-line paper in the American Journal of Obstetrics & Gynecology.As Drs. Jane R. Schwebke told Reuters Health by email, “In this large prospective study, tinidazole was not superior to metronidazole for the treatment of bacterial vaginosis but was as efficacious.””A better understanding of the pathogenesis of bacterial vaginosis,” she added, “is needed to guide the development of new therapies.”Drs. Schwebke and Renee A. Desmond note that available treatment regimens have been disappointing in terms of initial cure and recurrence rates. However, tinidazole which has been used for decades in Europe was recently licensed in the US.Because of its pharmacokinetics, there was hope that it would do better than did metronidazole, but there are no comparative data on muti-dose therapy.To investigate, the researchers enrolled 493 heterosexual women. None had evidence of STD. They were randomized to 7 days of twice-daily treatment with metronidazole 500 mg, tinidazole 500 mg or tinidazole 1 gm.At 14 days, the overall cure rate was 76.8%. Cure or improvement was seen in 80.3% of the metronidazole group, 73.1% of the low dose tinidazole group and 82.5% of the high dose group.Corresponding rates at 1 month were 55.2%, 58.0% 62.3%,. Recurrence rates were 33.3%, 30.2% and 22.5%.There were no significant differences in adverse events across treatment arms, although more patients in the high dose tinidazole group reported experiencing a bad taste.Women who admitted to engaging in sexual intercourse during the study were significantly more likely to have bacterial vaginosis at the follow-up visit.Given that tinidazole did not demonstrate enhanced efficacy, the researchers conclude that “New approaches to therapy for this common infection are needed.”Am J Obstet Gynecol 2010.