Drugs for treating giardiasis

Abstract

Background: There can be a high rate of recurrence of disease after initial drug treatment for giardiasis. These drugs also have a range of adverse effects.

Objectives: The objective of this review was to assess the effects of drug treatments for giardiasis.

Search strategy: We searched the Cochrane Infectious Diseases Group trials register, the Cochrane Controlled Trials Register, Medline and Embase, Current Contents, reference lists of articles.

Selection criteria: Randomised and quasi-randomised trials of drug therapy for giardiasis compared with placebo or another drug.

Data collection and analysis: Two reviewers independently assessed trial quality and extracted data.

Main results: Thirty-four trials were included. Only one trial was without serious methodological flaws. Compared with placebo, drug treatment was associated with an improved cure rate (odds ratio 11.5, 95% confidence interval 2.3 to 58). Metronidazole treatment longer than three days had a better parasitological cure rate than other long treatment courses (odds ratio 2.4, 95% confidence interval 1.3 to 4.4), but there was significant heterogeneity between the trials. Single dose therapy appeared equally effective as longer treatment courses (odds ratio 0.33, 95% confidence interval 0.08 to 1.34). Within the single dose regimens, tinidazole had a comparable parasitological cure rate to other short therapies (odds ratio 3.4, 95% confidence interval 0.95 to 12), but had a higher clinical cure rate (odds ratio 5.3, 95% 2.7-10.7).

Reviewer's conclusions: A single dose of tinidazole appears to give the highest clinical cure rate for giardiasis with relatively few adverse effects.