Materials and Methods: A systematic literature search was conducted in 2 electronic databases - PMC and Cochrane. The search was restricted to the articles published during the last 5 years. First-level screening was done to select articles for the review on the basis of title and abstract. Then, full texts of selected articles were studied, and relevant articles were selected to be included in this review. Articles selected were critically appraised to evaluate their quality.

Results: Literature search revealed 837 articles in PMC, 15 in Clinical trial register of US National library, and 43 in Cochrane. Additional 6 articles were identified by hand search. Eleven clinical trials were included in this review.