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(dor ZOLE a mide)

Index Terms

  • Dorzolamide HCl
  • Dorzolamide Hydrochloride

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution, Ophthalmic:

Trusopt: 2% (10 mL)

Generic: 2% (10 mL)

Brand Names: U.S.

  • Trusopt

Pharmacologic Category

  • Carbonic Anhydrase Inhibitor (Ophthalmic)
  • Ophthalmic Agent, Antiglaucoma


Reversible inhibition of the enzyme carbonic anhydrase resulting in reduction of hydrogen ion secretion at renal tubule and an increased renal excretion of sodium, potassium, bicarbonate, and water to decrease production of aqueous humor; also inhibits carbonic anhydrase in central nervous system to retard abnormal and excessive discharge from CNS neurons


Topical: Reaches systemic circulation where it accumulates in RBCs during chronic dosing as a result of binding to CA-II


In RBCs during chronic administration


To N-desethyl metabolite (less potent than parent drug)


Urine (as unchanged drug and metabolite, N-desethyl)

Duration of Action

8 to 12 hours

Half-Life Elimination

Terminal RBC half-life: 147 days; washes out of RBCs nonlinearly, resulting in a rapid decline of drug concentration initially, followed by a slower elimination phase with a half-life of about 4 months

Protein Binding


Use: Labeled Indications

Elevated intraocular pressure: Treatment of elevated intraocular pressure (IOP) in patients with ocular hypertension or open-angle glaucoma


Hypersensitivity to dorzolamide or any component of the formulation

Dosing: Adult

Elevated intraocular pressure: Ophthalmic: Instill 1 drop in the affected eye(s) 3 times daily

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Refer to adult dosing.

Dosing: Renal Impairment

CrCl ≥30 mL/minute: There are no dosage adjustments provided in the manufacturer’s labeling.

CrCl <30 mL/minute: Use is not recommended (has not been studied).

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling (have not been studied); use with caution.


Ophthalmic: If more than one topical ophthalmic drug is being used, administer the drugs at least 5 minutes apart. Remove contact lens prior to administration and wait 15 minutes before reinserting. Avoid allowing the tip of the dispensing container to contact the eye or surrounding structures.


Store at 15°C to 30°C (59°F to 86°F). Protect from light.

Drug Interactions

Alpha-/Beta-Agonists (Indirect-Acting): Carbonic Anhydrase Inhibitors may increase the serum concentration of Alpha-/Beta-Agonists (Indirect-Acting). Monitor therapy

Carbonic Anhydrase Inhibitors: May enhance the adverse/toxic effect of other Carbonic Anhydrase Inhibitors. The development of acid-base disorders with concurrent use of ophthalmic and oral carbonic anhydrase inhibitors has been reported. Management: Avoid concurrent use of different carbonic anhydrase inhibitors if possible. Monitor patients closely for the occurrence of kidney stones and with regards to severity of metabolic acidosis. Avoid combination

Adverse Reactions

Frequency not always defined.

Dermatologic: Skin rash

Gastrointestinal: Bitter taste (~25% following administration), fatigue, headache, nausea

Genitourinary: Urolithiasis

Hypersensitivity: Local ocular hypersensitivity reaction (~10%)

Neuromuscular & skeletal: Weakness

Ocular: Burning sensation of eyes (~33%), eye discomfort (~33%), stinging of eyes (~33%), superficial punctate keratitis (10% to 15%), blurred vision (1% to 5%), conjunctivitis (1% to 5%), eyelid irritation (1% to 5%), eye redness (1% to 5%), lacrimation (1% to 5%), photophobia (1% to 5%), xerophthalmia (1% to 5%), iridocyclitis

<1% (Limited to important or life-threatening): Angioedema, bronchospasm, choriodal detachment (following filtration procedures), dyspnea, epistaxis, myopia (transient), ocular pain, paresthesia, Stevens-Johnson syndrome, throat irritation, toxic epidermal necrolysis


Concerns related to adverse effects:

• Bacterial keratitis: Inadvertent contamination of multiple-dose ophthalmic solutions has caused bacterial keratitis.

• Ocular effects: Local ocular adverse effects (primarily conjunctivitis and lid reactions) were reported with chronic administration; many resolved upon discontinuation of drug therapy. Choroidal detachment has been reported after filtration procedures.

• Sulfonamide (“sulfa”) allergy: Dorzolamide is a sulfonamide; although administered ocularly, systemic absorption may occur and could result in hypersensitivity. Discontinue use if signs of hypersensitivity or a serious reaction occur.

• Systemic effects: Systemic absorption and adverse effects (similar to sulfonamides) including, blood dyscrasias, Stevens-Johnson syndrome, toxic epidermal necrolysis, fulminant hepatic necrosis, agranulocytosis, aplastic anemia, and other blood dyscrasias may occur with ophthalmic use.

Disease-related concerns:

• Corneal endothelium: Use with caution in patients with low endothelial cell counts; may be at increased risk of corneal edema.

• Hepatic impairment: Use with caution in patients with hepatic impairment (has not been studied).

• Renal impairment: Use is not recommended in patients with severe renal impairment (CrCl <30 mL/minute) (has not been studied).

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed.

Special populations:

• Contact lens wearers: Some products contain benzalkonium chloride which may be absorbed by soft contact lenses; remove lens prior to administration and wait 15 minutes before reinserting.

Other warnings/precautions:

• Appropriate use: Should be used in combination with therapeutic interventions for the treatment of acute angle-closure glaucoma.

Monitoring Parameters

Ophthalmic exams and IOP periodically

Pregnancy Risk Factor


Pregnancy Considerations

Adverse events have been observed in animal reproduction studies following systemic administration. IOP is usually lower during pregnancy. If topical medications for the treatment of glaucoma in pregnant women cannot be discontinued because small increases in IOP cannot be tolerated, the minimum effective dose should be used in combination with punctual occlusion to decrease exposure to the fetus (Johnson, 2001).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience blurred vision, bad taste, dry eyes, watery eyes, or sensitivity to light. Have patient report immediately to prescriber signs of liver problems (dark urine, feeling tired, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin or eyes), vision changes, eye pain, severe eye irritation, edema of eye or eyelid, chills, pharyngitis, loss of strength and energy, or signs of Stevens-Johnson syndrome/toxic epidermal necrolysis (red, swollen, blistered, or peeling skin [with or without fever]; red or irritated eyes; or sores in mouth, throat, nose, or eyes) (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.