Managing trichomonal vaginitis refractory to conventional treatment with metronidazole.

Abstract

Three patients with vulvovaginitis caused by Trichomonas vaginalis, which was refractory to conventional treatment with metronidazole are described. The T vaginalis strain isolated from one patient was resistant to metronidazole (minimum inhibitory concentration (MIC) more than 100 mg/l) under aerobic conditions, although under anaerobic conditions it was as susceptible as a normal reference strain. The effect of the concomitant use of other medication and the influence of other vaginal pathogens on the efficacy of metronidazole are highlighted.

Tinidazole Therapy for Metronidazole‐Resistant Vaginal Trichomoniasis

“…Thus, many consider metronidazole resistance to be a clinical diagnosis made on the basis of a compliant patient's lack of response to appropriate therapy, after reinfection has been excluded. Moreover, the literature is replete with anecdotal reports and larger patient series in which metronidazole resistance seems relative and may be overcome with increasing doses of the drug [2,[15][16][17][18][19]. Accordingly, current Centers for Disease Control and Prevention (CDC) guidelines for patients who do not respond to metronidazole treatment recommend retreatment with metronidazole at a dosage of 500 mg b.i.d.…”

Treatment of Infections Caused by Metronidazole-ResistantTrichomonas vaginalis

“…In cases in which trichomonad drug resistance is very high and toxic levels of metronidazole are required, administration of the drug intravenously or in combination with oral and vaginal therapy may minimize side effects. One treatment protocol is available that recommends regimens for marginal, low, moderate, and high levels of metronidazole resistance (6). This highlights the need for metronidazole susceptibility testing in refractory T. vaginalis infection, as well as the need for alternate therapies to avoid increasing resistance in wild-type strains as a result of increased metronidazole pressure.…”

“…Vaginal preparations of metronidazole (cream or insert) have much lower cure rates (20%), probably because low absorption into the serum leads to poor delivery to the genitourinary glands and organs other than the vagina that may have become infected by T. vaginalis (49). A protocol exists that takes the above factors into consideration when determining further treatment for refractory trichomoniasis (6).…”

Bacterial Vaginosis and Trichomoniasis: Epidemiology and Management of Recurrent Disease

“…[4][5][6] Although metronidazole 7 resistance is increasing, it is still uncommon. The 2-g single-dose regimen minimizes noncompliance and is more practical for the treatment of sexual partners.…”

“…Sexual partners should be treated since reinfection rates of 6.2% to 23.7% are noted in women whose sexual partners are not treated simultaneously. [6][7][8] …”