Evaluation of Generic versus Original Prostaglandin Analogues in the Treatment of Glaucoma: A Systematic Review and Meta-Analysis

TOPIC: An evaluation of the efficacy and tolerability of generic prostaglandin analogues (PGAs) compared with their original counterpart.

CLINICAL RELEVANCE: This systematic review was initiated to enlighten ophthalmologists and patients in the use of original and generic ophthalmic solutions.

METHODS: A literature search was conducted on PubMed, EMBASE, MEDLINE, Clinicaltrials.gov, and the World Health Organization International Clinical Trials Registry Platform, along with a manual search, from the marketing of the first PGA, latanoprost, in 1995 to the present. Randomized controlled trials comparing an original PGA with its generic counterpart were included. The last literature search was conducted in June 2019. Risk of bias was assessed by 2 independent reviewers using the Cochrane Handbook for Systematic Reviews Tool. The primary outcome was reduction of intraocular pressure (IOP) from baseline. Secondary outcomes included tolerability, ocular surface health, quality of life, disease progression, and cost-effectiveness. Meta-analysis of the primary outcome was planned.

RESULTS: Of 385 screened articles, 6 were included in a broad characterization and in the meta-analysis. A total of 619 patients were enrolled. The duration of the studies ranged from 3 to 16 weeks. Meta-analysis of all 6 studies denied any clinically significant difference in efficacy, and the 95% confidence interval included nil (-0.50 to 0.04 mmHg). The evidence was of moderate certainty because of unclear or high risk of bias in all studies. There were no reported differences in tolerability.

CONCLUSIONS: Trials comparing original and generic PGAs did not show a clinically significant difference in IOP-lowering effect or tolerability. However, the quality of the trials is suboptimal. Overall, there is uncertainty, and further research is needed to confirm equivalence.