Oral versus intra-vaginal imidazole and triazole anti-fungal treatment of uncomplicated vulvovaginal candidiasis (thrush)

Background: Anti-fungals are available for oral and intra-vaginal treatment of uncomplicated vulvovaginal candidiasis.

Objectives: The primary objective of this review is to assess the relative effectiveness (clinical cure) of oral versus intra-vaginal anti-fungals for the treatment of uncomplicated vulvovaginal candidiasis. Secondary objectives include the assessment of the relative effectiveness in terms of mycological cure, in addition to safety, side effects, treatment preference, time to first relief of symptoms, and costs.

Search methods: We searched CENTRAL, MEDLINE, Embase, and two trials registers on 29 August 2019 together with reference checking and citation searching.

Selection criteria: We included randomised controlled trials published in any language comparing at least one oral anti-fungal with one intra-vaginal anti-fungal in women (aged 16 years or over) with a mycological diagnosis (positive culture, microscopy for yeast, or both) of uncomplicated vulvovaginal candidiasis. We excluded trials if they solely involved participants who were HIV positive, immunocompromised, pregnant, breast feeding or diabetic.

Data collection and analysis: We used standard methodological procedures as recommended by Cochrane.

Main results: This review includes 26 trials (5007 participants). Eight anti-fungals are represented. All but three trials included participants with acute vulvovaginal candidiasis. Trials were conducted in Europe: UK (3), Croatia (2). Finland (2), the Netherlands (2), Germany (1), Italy (1), Sweden (1) and one trial across multiple European countries, USA (7) Thailand (2), Iran (2), Japan (1) and Africa (Nigeria) (1). The duration of follow-up varied between trials. The overall risk of bias of the included trials was high. There was probably little or no difference shown between oral and intra-vaginal anti-fungal treatment for clinical cure at short-term follow-up (OR 1.14, 95% CI 0.91 to 1.43; 13 trials; 1859 participants; moderate-certainty evidence) and long-term follow-up (OR 1.07, 95% CI 0.77 to 1.50; 9 trials; 1042 participants; moderate-certainty evidence). The evidence suggests that if the rate of clinical cure at short-term follow-up with intra-vaginal treatment is 77%, the rate with oral treatment would be between 75% and 83%; if the rate of clinical cure at long term follow-up with intra-vaginal treatment is 84%, the rate with oral treatment would be between 80% and 89%. Oral treatment probably improves mycological cure over intra-vaginal treatment at short term (OR 1.24, 95% CI 1.03 to 1.50: 19 trials; 3057 participants; moderate-certainty evidence) and long-term follow-up (OR 1.29, 95% CI 1.05 to 1.60; 13 trials; 1661 participants; moderate-certainty evidence). The evidence suggests that if the rate of mycological cure at short-term follow-up with intra-vaginal treatment is 80%, the rate with oral treatment would be between 80% and 85%; if the rate of mycological cure at long-term follow-up with intra-vaginal treatment is 66%, the rate with oral treatment would be between 67% and 76%. In terms of patient safety, there is a low risk of participants withdrawing from the studies due to adverse drug effects for either treatment (23 trials; 4637 participants; high-certainty evidence). Due to the low certainty of evidence, it is undetermined whether oral treatments reduced the number of side effects compared with intra-vaginal treatments (OR 1.04, 95% CI 0.84 to 1.29; 16 trials; 3155 participants; low-certainty evidence). The evidence suggests that if the rate of side effects with intra-vaginal treatment is 12%, the rate with oral treatment would be between 10% and 15%. We noted that the type of side effects differed, with intra-vaginal treatments being more often associated with local reactions, and oral treatments being more often associated with systemic effects including gastro-intestinal symptoms and headaches. Oral treatment appeared to be the favoured treatment preference over intra-vaginal treatment or no preference (12 trials; 2206 participants), however the data were poorly reported and the certainty of the evidence was low. There was little or no difference in time to first relief of symptoms between oral and intra-vaginal treatments: four trials favoured the oral treatment, four favoured intra-vaginal, one study reported no difference and one was unclear. The measurements varied between the 10 trials (1910 participants) and the certainty of the evidence was low. Costs were not reported in any of the trials.

Authors' conclusions: Oral anti-fungal treatment probably improves short- and long-term mycological cure over intra-vaginal treatment for uncomplicated vaginal candidiasis. Oral treatment was the favoured treatment preference by participants, though the certainty of this evidence is low. The decision to prescribe or recommend an anti-fungal for oral or intra-vaginal administration should take into consideration safety in terms of withdrawals and side effects, as well as cost and treatment preference. Unless there is a previous history of adverse reaction to one route of administration or contraindications, women who are purchasing their own treatment should be given full information about the characteristics and costs of treatment to make their own decision. If health services are paying the treatment cost, decision-makers should consider whether the higher cost of some oral anti-fungals is worth the gain in convenience, if this is the patient's preference.