Antiglaucoma carbonic anhydrase inhibitors: a patent review

Introduction: Glaucoma is one of the major causes of blindness, affecting together with age-related macular degeneration 70 million people worldwide. One of the therapeutic options for its management is based on the inhibition of the metalloenyme carbonic anhydrase (CA, EC 4.2.1.1). CA inhibitors (CAIs) diminish intraocular pressure (IOP) by reducing the rate of bicarbonate formation and thus secretion of the aqueous humor. Areas covered: The main classes of clinically used antiglaucoma CAIs are the sulfonamides with systemic (acetazolamide, methazolamide, ethoxzolamide and dichlorophenamide) and topical (dorzolamide and brinzolamide) action. A patent literature review covering the period 2007 - 2013 is presented. Expert opinion: This review presents an overview of the patent literature in the CAI antiglaucoma drug design field during the past 6 years. Most of the patents deal with sulfonamide/sulfamide/sulfamate CAIs, sulfonamides incorporating NO-donating moieties, as well as hybrids incorporating sulfonamide and prostaglandin (PG) analogs, were also reported. There is an urgent need for new antiglaucoma CAIs/approaches to treat and diagnose this disease in the very near future, as the last drug which has been discovered in the field (latanoprost) dates back > 10 years ago.