Dorzolamide
Glaucoma · Rx
Trade namesTrusopt
Drug classTopical carbonic anhydrase inhibitor
Strength2%
AvailabilityRx
Mechanism of actionInhibits carbonic anhydrase II in the ciliary epithelium, reducing bicarbonate and hence aqueous formation. ~15-20% IOP reduction. May improve ocular blood flow.
Indication / reason for useOpen-angle glaucoma and ocular hypertension; adjunct; useful in patients who cannot take beta-blockers. Also used in some cystoid macular edema / retinitis pigmentosa CME.
Usual adult dosing1 drop three times daily as monotherapy, twice daily as adjunct.
PreservativeBAK 0.0075%
Contact lensesRemove lenses; reinsert after 15 minutes.
Common / important adverse effectsMarked stinging and bitter taste (very common), transient blur, punctate keratitis; corneal endothelial decompensation in eyes with low endothelial cell counts (Fuchs, prior graft); rare sulfonamide hypersensitivity systemically.
Contraindications & cautionsSevere renal impairment (CrCl <30); true sulfonamide allergy is a labelled contraindication; compromised corneal endothelium.
Pregnancy / lactationLimited data; animal data show reduced fetal weight. Avoid where possible.
Practice notesCheck corneal status before prescribing to a Fuchs or post-graft patient, CAIs can tip a marginal endothelium into edema.
Chair-side reference only. Dosing, contraindications and pregnancy guidance here are not exhaustive. Confirm against the current prescribing information and the patient’s full history before prescribing or advising.