Dorzolamide is an inhibitor of carbonic anhydrase, inhibiting human isoforms II, V, VI, IX, XII, XIII, and XIV with Ki values between 3.5 and 52 nM. It less effectively inhibits human carbonic anhydrases I, III, and IV (Ki = 50, 8, and 8.5 μM, respectively). Topically applied inhibitors of carbonic anhydrase, including dorzolamide, are commonly used to treat glaucoma.