Fixed combinations of topical glaucoma medications

Topical medical therapy remains the first line of treatment in the management of glaucoma. Utilization studies and clinical trials have demonstrated that many patients with glaucoma require multiple medications to achieve adequate control of intraocular pressure. Fixed combinations of commonly used drugs have been developed, tested, and in some (but not all) cases, approved for use in the United States and abroad. In this review the authors discuss the principles of fixed combination therapy and examine the existing fixed combinations.

The first modern combination product was the dorzolamide-timolol fixed combination. It works better than either constituent and at least as well as concomitant therapy with both constituents. In comparison with newer agents, the dorzolamide-timolol fixed combination was equal in efficacy to latanoprost monotherapy, timolol and unoprostone concomitant therapy, and timolol and brimonidine concomitant therapy. Concomitant latanoprost and brimonidine demonstrated better efficacy than the dorzolamide-timolol fixed combination. The latanoprost-timolol fixed combination is available in many countries but not the United States. This combination has demonstrated modest additional efficacy over latanoprost monotherapy. The latanoprost-timolol fixed combination provided greater efficacy than concomitant timolol and brimonidine.

Fixed combinations offer benefits of convenience, cost, and safety, but limit individualization of dosing. Understanding the advantages and disadvantages of prescribing fixed combinations facilitates success in using these products in clinical practice.