From the Guidelines
Trichomonas vaginalis infection should be treated with metronidazole 500 mg orally twice daily for 7 days, or alternatively, a single 2-gram dose of metronidazole taken orally, as this regimen has been shown to result in cure rates of approximately 90%-95% 1. The diagnosis of Trichomonas vaginalis infection can be made through microscopic examination of vaginal secretions or urine, or through more sensitive nucleic acid amplification tests 1. Some key points to consider in the diagnosis and treatment of Trichomonas vaginalis infection include:
- The infection is caused by a single-celled parasite and is a common sexually transmitted infection
- Symptoms in women include vaginal discharge (often yellow-green and frothy), itching, odor, and discomfort during urination or sex, while men are frequently asymptomatic but can experience urethral discharge or irritation
- Sexual partners should be treated simultaneously to prevent reinfection, even if they don't have symptoms
- Patients should abstain from alcohol during treatment and for 24 hours afterward due to potential disulfiram-like reactions
- Follow-up testing is recommended if symptoms persist after treatment 1 It's also important to note that certain strains of T. vaginalis can have diminished susceptibility to metronidazole, but most of these organisms respond to higher doses of metronidazole 1. In cases of treatment failure, the patient should be re-treated with metronidazole 500 mg twice a day for 7 days, and if treatment failure occurs again, the patient should be treated with a single, 2-g dose of metronidazole once a day for 3--5 days 1.
From the FDA Drug Label
Tinidazole is indicated for the treatment of trichomoniasis caused by Trichomonas vaginalis. The organism should be identified by appropriate diagnostic procedures. Metronidazole tablets are indicated for the treatment of symptomatic trichomoniasis in females and males when the presence of the trichomonad has been confirmed by appropriate laboratory procedures (wet smears and/or cultures)
The diagnosis of Trichomonas vaginalis infection should be made by identifying the organism through appropriate laboratory procedures, such as wet smears and/or cultures. The treatment for Trichomonas vaginalis infection is with either tinidazole or metronidazole. It is recommended that sexual partners of infected patients be treated simultaneously to prevent re-infection 2 3.
From the Research
Diagnosis of Trichomonas vaginalis Infection
- Trichomonas vaginalis is the most common curable sexually transmitted infection worldwide 4
- Diagnosis is typically made through wet smear preparations or other laboratory tests
Treatment of Trichomonas vaginalis Infection
- The Centers for Disease Control and Prevention recommend a single 2-g dose of metronidazole for the first line of treatment for T. vaginalis among human immunodeficiency virus (HIV) negative women 4
- However, studies have shown that multidose metronidazole may be more effective than single-dose metronidazole in treating T. vaginalis, with a pooled risk ratio of 1.87 (95% confidence interval, 1.23-2.82; P < 0.01) 4
- Tinidazole is another accepted trichomonacide, with a cure rate of 95% in a single-blind controlled trial 5
- A single 2-g dose of tinidazole was found to be as effective as a 2-g single dose of metronidazole in the treatment of vaginal trichomoniasis 5
- Metronidazole tablets, benzoyl metronidazole suspension, and tinidazole tablets each given as a single 2-g bolus dose were found to be effective forms of treatment for Trichomonas vaginalis vaginitis, with cure rates of 100%, 100%, and 94.8%, respectively 6
- Tinidazole therapy has been shown to be effective in treating metronidazole-resistant vaginal trichomoniasis, with a cure rate of 92% in one study 7
Treatment of Metronidazole-Resistant Trichomonas vaginalis Infection
- Metronidazole resistance has been documented, and treatment options are limited 8
- Tinidazole has been shown to be effective in treating metronidazole-resistant T. vaginalis, despite the high doses used 7
- Topical paromomycin was effective in 58% of patients treated, but frequent local vulvovaginal adverse reactions precluded extensive use 7