sulfonamide mainly distributed to erythrocytes. Probably insignificant systemic load. CYP metabolised, long duration of the final elimination phase.

(To be edited, initial data ST OCT 04) sulfonamide used in eyedrops (20 mg/mL) to reduce the intraocular pressure in glaucoma. Converted to N-desethyl dorzolamide which binds to carbanhydrase. Reaches circulation in topical application but due to effective bindnding to erytrocyte carboanhydrases the plasma levels are very low. Metabolized by CYPs 3A3/4 and 2C9/10. A final elimination phase with a half time of four months takes place after termination of treatment.