Susceptibility of Trichomonas vaginalis Strains to Metronidazole: Response to Treatment

• Published in: Sexually transmitted diseases 1983-07, Vol.10 (3), p.119-122
• Main Authors: RALPH, EDWARD D., DARWISH, RIAD, AUSTIN, THOMAS W., SMITH, ELIZABETH A., PATTISON, FREDERICK L. M.
• Format: Article
• Language: English
• Subjects: Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiparasitic agents; Biological and medical sciences; Clinical Trials as Topic; Drug Resistance, Microbial; Female; Humans; Medical sciences; Metronidazole - administration & dosage; Metronidazole - pharmacology; Metronidazole - therapeutic use; Microbial Sensitivity Tests; Original Articles; Pharmacology. Drug treatments; Trichomonas vaginalis - drug effects; Trichomonas Vaginitis - drug therapy
• ISSN: 0148-5717; 1537-4521
• DOI: 10.1097/00007435-198307000-00003

The effect of the susceptibility of Trichomonas vaginalis strains to metronidazole on response to treatment was determined from minimal inhibitory concentrations (MICs) for organisms isolated during a clinical trial in which single 1- and 2-g doses of metronidazole were compared. Fifty-seven strains were isolated from patients receiving 1 g of metronidazole, and 75 from those receiving 2 g. The mean MIC for all strains was 1.50 µg/ml (range, 0.5-4.5 µg/ml) and was similar in both groups. The mean MICs for isolates from patients who were cured were significantly less than the mean MICs of isolates from those who were treatment failures. The cure rates, compared to the MICs for the strains isolated, varied from 84% (MIC, 0.5 µg/ml) to 16% (MIC, ≥ 3.0 µg/ml) for the group given the single 1-g dose and from 94% (MIC, 0.5 µg/ml) to 43% (MIC, ≥3.0 µg/ml) for those given the 2-g dose. The data demonstrate a direct relationship between susceptibility of T. vaginalis isolates and response to treatment with single-dose regimens of metronidazole.