From the Guidelines
Trichomonas vaginalis infection should be treated with oral metronidazole 500 mg twice daily for 7 days or as a single 2-gram dose, as this regimen has resulted in cure rates of approximately 90%-95% 1. For pregnant patients, the 7-day regimen is preferred.
Key Considerations
- Sexual partners should also be treated simultaneously to prevent reinfection, even if they have no symptoms.
- Patients should abstain from alcohol during treatment and for 24 hours afterward due to potential disulfiram-like reactions.
- Trichomonas is a common sexually transmitted infection caused by a protozoan parasite that typically causes vaginal discharge, itching, and odor in women, while men are often asymptomatic carriers.
- The infection increases risk of HIV transmission and can lead to complications like pelvic inflammatory disease if untreated.
Diagnosis and Follow-Up
- Diagnosis of vaginal trichomoniasis is usually performed by microscopy of vaginal secretions, but this method has a sensitivity of only about 60%--70% 1.
- Culture is the most sensitive commercially available method of diagnosis.
- Follow-up testing is recommended if symptoms persist after treatment, as resistance to metronidazole can occur in about 5% of cases.
Alternative Treatments
- Alternative treatment for resistant cases includes higher doses of metronidazole or tinidazole 2 grams as a single dose.
- Patients should be screened for other sexually transmitted infections as co-infections are common.
Treatment Efficacy
- Metronidazole gel is approved for treatment of BV, but it is considerably less efficacious for treatment of trichomoniasis than oral preparations of metronidazole and is not recommended for use 1.
From the FDA Drug Label
1 INDICATIONS AND USAGE 1. 1 Trichomoniasis Tinidazole is indicated for the treatment of trichomoniasis caused by Trichomonas vaginalis.
2 DOSAGE AND ADMINISTRATION 2. 3 Trichomoniasis The recommended dose in both females and males is a single 2 g oral dose taken with food.
The treatment for Trichomoniasis caused by Trichomonas vaginalis is a single 2 g oral dose of tinidazole taken with food, and it is recommended that sexual partners be treated simultaneously to prevent re-infection 2.
From the Research
Overview of Trichomoniasis
- Trichomoniasis is the most common non-viral sexually transmitted infection worldwide, associated with serious reproductive morbidity, poor birth outcomes, and amplified HIV transmission 3.
- The infection is caused by the parasite Trichomonas vaginalis and can be treated with metronidazole.
Treatment Options
- Single-dose metronidazole is the first-line treatment for trichomoniasis, but its efficacy can be altered by bacterial vaginosis in HIV-infected women 3.
- A 7-day dose of metronidazole (500 mg twice daily) has been shown to be more effective than a single 2-g dose in clearing the infection in women 3, 4, 5.
- A meta-analysis found that the pooled risk ratio indicated higher treatment failure for single dose compared to multidose metronidazole 4.
Comparison of Treatment Regimens
- A study published in JAMA found that the cure rates for single-dose and 7-day metronidazole regimens were not significantly different, but the single-dose regimen was easier to administer and less expensive 6.
- However, more recent studies have suggested that the 7-day dose regimen is more effective in clearing the infection and should be used as the first-line treatment for T. vaginalis-infected women 3, 4, 5.
Challenges and Future Directions
- High rates of repeat infections are found among T. vaginalis-infected persons after single-dose metronidazole treatment, and treatment efficacy may be influenced by vaginal ecology 7.
- Future studies should examine the importance of treating asymptomatic T. vaginalis, the best treatment for men, and the influence of the microbiome on treatment efficacy 5.