← All medications

Dorzolamide

Medication carbonic anhydrase inhibitor (ophthalmic) other
Aka: Trusopt, Cosopt
Brands seen in Singapore: Trusopt, Zolichek, Cosopt, Cosopt-S, Zolichek-T
Not medical advice. Check with your doctor or pharmacist before you start, stop or change the timing of anything you take.
How to use
What it’s for
Lowering eye pressure in glaucoma or ocular hypertension
When to take
SG label: one drop three times daily when used alone
Take with
Other eye drops given at least ten minutes apart (SG label)
Pros & cons
Pros
  • SG label: twice daily when added to a beta-blocker
  • SG label: covers open-angle and secondary glaucomas
  • FDA: tested in children in a 3-month trial
Cons
  • FDA: stinging or burning in about a third of people
  • FDA: a bitter taste in about a quarter of people
  • FDA: it is a sulfonamide — rare severe skin reactions
Sources
  1. HSA — Listing of Registered Therapeutic Products (data.gov.sg dataset d_767279312753558cbf19d48344577084), Forensicclassification column; 5,511 rows cached at /tmp/hsa_all.json and filtered locally, never re-fetched — 6 dorzolamide rows · read 2026-08-27
    what it says
    “All 6 registered dorzolamide products read "Prescription Only" — SIN08880P TRUSOPT OPHTHALMIC SOLUTION 2% and SIN14985P ZOLICHEK 2% (single-ingredient, ATC S01EC03), plus COSOPT, COSOPT-S, ZOLICHEK-T and DORZOLAMIDE AND TIMOLOL STADA (with timolol, S01ED51).”
  2. MOH National Drug Formulary — TRUSOPT OPHTHALMIC SOLUTION 2% [SIN08880P], Indications (SG package insert) · read 2026-08-27
    what it says
    “TRUSOPT Ophthalmic Solution is indicated in the treatment of elevated intraocular pressure in patients with: ocular hypertension; open-angle glaucoma; pseudoexfoliative glaucoma and other secondary open-angle glaucomas”
  3. MOH National Drug Formulary — TRUSOPT 2% [SIN08880P], Dosage and Administration · read 2026-08-27
    what it says
    “When used as monotherapy, the dose is one drop … in the affected eye(s) three times daily. When used as adjunctive therapy with an ophthalmic beta-blocker … two times daily … at least ten minutes apart.”
  4. MOH National Drug Formulary — TRUSOPT 2% [SIN08880P], Contraindications · read 2026-08-27
    what it says
    “TRUSOPT is contraindicated in patients who are hypersensitive to any component of this product.”
  5. MOH National Drug Formulary — TRUSOPT 2% [SIN08880P], product information block · read 2026-08-27
    what it says
    “Forensic Classification: PRESCRIPTION ONLY MEDICINES · Anatomical Therapeutic Chemical (ATC) code S01EC03 · Prescription-only Medicines with Exemptions for Supply without Prescription: NA”
  6. US FDA label for Dorzolamide Hydrochloride Ophthalmic Solution 2% (Sagent), section 1, via openFDA drug/label.json (effective 2026-01-09) · read 2026-08-27
    what it says
    “Dorzolamide Hydrochloride Ophthalmic Solution is a carbonic anhydrase inhibitor indicated for the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma.”
  7. US FDA label for Dorzolamide Hydrochloride Ophthalmic Solution 2%, section 2, via openFDA · read 2026-08-27
    what it says
    “The dose is one drop of Dorzolamide Hydrochloride Ophthalmic Solution in the affected eye(s) three times daily … If more than one topical ophthalmic drug is being used, the drugs should be administered at least five minutes apart.”
  8. US FDA label for Dorzolamide Hydrochloride Ophthalmic Solution 2%, section 5 Warnings and Precautions, via openFDA · read 2026-08-27
    what it says
    “contains dorzolamide, a sulfonamide … Fatalities have occurred, although rarely, due to severe reactions to sulfonamides including Stevens-Johnson syndrome … Sensitization may recur … increased potential for developing corneal edema in patients with low endothelial cell counts.”
  9. US FDA label for Dorzolamide Hydrochloride Ophthalmic Solution 2%, section 6 Adverse Reactions, via openFDA · read 2026-08-27
    what it says
    “ocular burning, stinging, or discomfort immediately following ocular administration (approximately one-third of patients). Approximately one-quarter of patients noted a bitter taste … Superficial punctate keratitis occurred in 10 to 15% of patients”
  10. US FDA label for Dorzolamide Hydrochloride Ophthalmic Solution 2%, section 7 Drug Interactions, via openFDA · read 2026-08-27
    what it says
    “The concomitant administration of Dorzolamide Hydrochloride Ophthalmic Solution and oral carbonic anhydrase inhibitors is not recommended … toxicity associated with high-dose salicylate therapy … the potential for such drug interactions should be considered”
  11. US FDA label for Dorzolamide Hydrochloride Ophthalmic Solution 2%, section 8.4 Pediatric Use, via openFDA · read 2026-08-27
    what it says
    “Safety and effectiveness of Dorzolamide Hydrochloride Ophthalmic Solution have been demonstrated in pediatric patients in a 3-month, multicenter, double-masked, active-treatment-controlled trial.”
  12. US FDA label for Dorzolamide Hydrochloride Ophthalmic Solution 2%, section 17 Patient Counseling Information, via openFDA · read 2026-08-27
    what it says
    “contains benzalkonium chloride which may be absorbed by soft contact lenses. Contact lenses should be removed prior to administration of the solution. Lenses may be reinserted 15 minutes following … administration.”
Report a correction View as JSON

Updated 2026-08-29. Every line above traces to a numbered source. Kozen-X is not a medical device and does not give medical advice. It lists what published sources have written down — nothing more. A pair not listed is unrecorded, not cleared. Before you start, stop or re-time anything, talk to your doctor or pharmacist.