Trusopt®
Dorzolamide 2% · ophthalmic solution
Antiglaucoma
Approved uses
Elevated IOP in ocular hypertension or open-angle glaucoma
1 drop in the affected eye(s) TID
Peak IOP falls about 23% and afternoon trough about 17%, sustained over 1 year.
OFF-LABELNot in the FDA label for this product
Cystoid macular edema in retinitis pigmentosa
1 drop 2% TID in the affected eye(s)
Meta-analysis · nonrandomized
Meta-analysis of 11 nonrandomized clinical reports (194 patients, 358 eyes, of which 243 eyes received a topical carbonic anhydrase inhibitor) pooled oral and topical treatment and found central macular thickness fell 46.02 microns (95% CI 31.08 to 60.96), while the effect on visual acuity was inconsistent across studies. The authors state the anatomic benefit rests on nonrandomized data and call for randomized trials.
Foveal schisis in X-linked retinoschisis
1 drop 2% BID to TID in both eyes, long-term
Retrospective series · n=10
Retrospective interventional case series of 10 genetically confirmed patients (18 eyes) followed a mean 8.4 years: mean central subfield thickness went from 429.88 to 372.28 microns (P = 0.10, not significant) while mean logMAR acuity improved from 0.45 to 0.34 (P below 0.01). No randomized data exist, and paradoxical worsening of macular cysts on topical therapy has been reported in a single case.
Contraindications
Hypersensitivity to any component of this product
Available FormsOphthalmic solution, 5 mL in a 7.5 mL bottle, 10 mL in a 10 mL bottle, dorzolamide 2% (20 mg/mL)
Mechanism of ActionCarbonic anhydrase II inhibitor: blocking the enzyme in the ciliary processes slows bicarbonate formation, reducing sodium and fluid transport and lowering aqueous humor secretion. At exposures simulating topical dosing, systemic carbonic anhydrase inhibition stayed below the level expected to affect renal function or respiration.
Warnings & Precautions
- Sulfonamide hypersensitivity: Systemically absorbed sulfonamide; fatalities have occurred, although rarely, from Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia and other blood dyscrasias. Discontinue if signs of serious reaction appear; sensitization can recur on re-exposure by any route.
- Corneal endothelium: Higher risk of corneal edema with low endothelial cell counts.
- Allergic-type local reactions: Conjunctivitis and lid reactions with chronic use; they resolve on discontinuation, so stop and evaluate before any rechallenge.
- Severe renal impairment: Not recommended below CrCl 30 mL/min; drug and metabolite are renally cleared.
- Hepatic impairment: Not studied; use with caution.
- Oral carbonic anhydrase inhibitors: Additive systemic carbonic anhydrase inhibition; concomitant use not recommended.
- High-dose salicylate therapy: Acid-base and electrolyte disturbances reported with oral carbonic anhydrase inhibitors; consider the interaction.
- Soft contact lenses: Benzalkonium chloride is absorbed; remove lenses before instillation, reinsert 15 minutes later.
- Acute angle-closure glaucoma: Management requires intervention beyond ocular hypotensive agents.
- Bacterial keratitis: Reported from contaminated multi-dose containers, mostly in eyes with concurrent corneal disease or epithelial disruption.
Common Side Effects
- Ocular: Burning, stinging, or discomfort immediately after instillation, about one-third of patients.
- Superficial punctate keratitis: 10% to 15%.
- Ocular allergic reaction: Signs and symptoms in about 10%; conjunctivitis and lid reactions 1% to 5%.
- Other ocular: Blurred vision, eye redness, tearing, dryness, photophobia, 1% to 5%.
- Systemic: Bitter taste in about one-quarter of patients; headache, nausea, asthenia and fatigue infrequent.
- Rare reactions: Skin rash, urolithiasis, iridocyclitis.
- Postmarketing: Stevens-Johnson syndrome, toxic epidermal necrolysis, angioedema, bronchospasm, transient myopia, choroidal detachment after filtration surgery, eyelid crusting.
Pregnancy & LactationPregnancy: No adequate and well-controlled studies in pregnant women. Oral dorzolamide caused fetal vertebral malformations in rabbits at 37 times the clinical exposure and was not teratogenic at up to 15 times; rat dosing in late gestation and lactation delayed offspring growth at 52 times.
Lactation: No human data on milk presence, effects on the breastfed infant, or milk production; drug and its N-desethyl metabolite are detected in the milk of lactating rats.
Pediatric UseEffectiveness shown in a 3-month, double-masked, active-controlled trial.