Pharmacogenetic Explanation for Excessive β-Blockade Following Timolol Eye Drops

Abstract

An individual's debrisoquin phenotype is an important determinant of beta-blockade following timolol eye drops, and metabolism of timolol is inhibited and beta-blockade increased by coadministration of oral quinidine. Clinicians should be aware of the potential for drug interactions that occur when orally administered drugs inhibit the metabolism of a topically administered drug.