Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
DORZOLAMIDE HYDROCHLORIDE vs AZOPT
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Dorzolamide hydrochloride is a carbonic anhydrase II inhibitor. By inhibiting carbonic anhydrase in the ciliary processes of the eye, it reduces aqueous humor secretion, thereby lowering intraocular pressure.
Carbonic anhydrase inhibitor; inhibits carbonic anhydrase II (CA-II) in ciliary processes, reducing aqueous humor secretion and intraocular pressure.
Treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma,Adjunctive therapy with beta-blockers in patients with open-angle glaucoma or ocular hypertension
Open-angle glaucoma,Ocular hypertension
One drop of 2% solution in the affected eye(s) three times daily.
One drop in the affected eye(s) twice daily. Instill at least 10 minutes apart from other ophthalmic medications.
Terminal elimination half-life is approximately 4 months for red blood cell carbonic anhydrase II binding; systemic half-life of free drug is about 3-4 hours.
Terminal elimination half-life is approximately 111 minutes (1.85 hours) in plasma after topical ocular administration; prolonged in renal impairment (creatinine clearance <30 m L/min).
Dorzolamide is metabolized primarily by hepatic cytochrome P450 enzymes, specifically CYP2C9, to N-desethyl-dorzolamide. It forms N-acetylated metabolites as well as the N-desethyl metabolite. Minor renal elimination of unchanged drug occurs.
Not significantly metabolized; primarily excreted unchanged in urine via renal tubular secretion.
Renal: approximately 70% of a topically applied dose is excreted unchanged in urine over 120 hours; <2% fecal.
Primarily renal excretion as unchanged drug (approximately 70% of a topically applied dose is absorbed systemically and excreted unchanged in urine); minimal biliary/fecal elimination (<5%).
Approximately 33% bound to plasma proteins, primarily albumin.
Approximately 33% bound to plasma proteins (mainly albumin).
Wide distribution: apparent Vd is approximately 0.53 L/kg; extensive binding to carbonic anhydrase in red blood cells and tissues.
Volume of distribution is approximately 0.35 L/kg, indicating distribution primarily into extracellular fluid.
Topical ophthalmic: systemic absorption is minimal (approximately 2-4% of administered dose reaches systemic circulation due to nasolacrimal drainage and ocular absorption).
Ocular bioavailability is not quantified due to local administration; systemic bioavailability after topical ocular dosing is approximately 70% via nasolacrimal absorption.
Contraindicated in severe renal impairment (Cr Cl <30 m L/min). No specific dose adjustment for mild to moderate impairment; use with caution.
No dosage adjustment required for systemic absorption is minimal. However, use caution in severe renal impairment (Cr Cl <30 m L/min) due to potential metabolite accumulation.
No specific dose adjustment required based on Child-Pugh classification; however, use with caution in severe hepatic impairment due to potential for systemic accumulation.
No dosage adjustment required for systemic absorption is minimal. Use caution in severe hepatic impairment (Child-Pugh class C) due to limited data.
Safety and efficacy not established in pediatric patients. No standard weight-based dosing guidelines available. Some sources recommend the same adult dose (one drop of 2% solution three times daily) for children aged ≥2 years; use with caution.
Approved for children ≥2 years: one drop in the affected eye(s) twice daily. For children <2 years: safety and efficacy not established.
No specific dose adjustment required, but elderly patients may be more susceptible to systemic effects; monitor for ocular irritation and electrolyte imbalance.
No specific dose adjustment required. Monitor for ocular irritation and systemic effects, as elderly patients may be more sensitive to adverse reactions such as hypotension or fatigue.
None
None
Sulfonamide hypersensitivity: Dorzolamide is a sulfonamide derivative; cross-reactivity may occur. Discontinue if signs of serious hypersensitivity reactions develop.,Corneal edema and endothelial decompensation: Use with caution in patients with compromised corneas (e.g., low endothelial cell count).,Ocular effects: Transient blurred vision, burning, stinging, and superficial punctate keratitis may occur.,Potential for metabolic acidosis: Carbonic anhydrase inhibitors can cause metabolic acidosis; use with caution in patients with renal impairment or those on concomitant topiramate or acetazolamide.,Bacterial keratitis: Risk with contaminated multidose containers.
Sulfonamide allergy (cross-reactivity possible),Corneal endothelial damage (risk increased with low endothelial cell count),Bacterial keratitis (with concomitant use of topical corticosteroids or ocular trauma),Contaminated dropper tip may cause ocular infections
Hypersensitivity to dorzolamide hydrochloride or any component of the formulation,Severe renal impairment (creatinine clearance < 30 m L/min),Hyperchloremic acidosis
Hypersensitivity to brinzolamide or any sulfonamides,Severe renal impairment (Cr Cl <30 m L/min) or hyperchloremic acidosis
None known. No dietary restrictions are required with topical dorzolamide use.
No significant food interactions known. However, avoid excessive salt intake if using systemic carbonic anhydrase inhibitors; for AZOPT, ocular use minimizes systemic effects, but caution in patients with electrolyte imbalances.
Dorzolamide is a carbonic anhydrase inhibitor. No adequate and well-controlled studies in pregnant women. In animal studies, no teratogenic effects at doses up to 2.5 mg/kg/day (rabbit) and 20 mg/kg/day (rat). Low systemic absorption (≈4% of ocular dose) minimizes fetal exposure. FDA Pregnancy Category C. Risk cannot be ruled out; use only if potential benefit justifies potential risk to fetus. No specific trimester risks.
Pregnancy Category C. No adequate studies in pregnant women. In animal studies, brinzolamide (active ingredient) showed no teratogenic effects at oral doses up to 6 mg/kg/day in rabbits and 20 mg/kg/day in rats. However, due to potential for fetal harm (systemic carbonic anhydrase inhibition causing acidosis), use only if clearly needed. First trimester: avoid if possible; second/third trimesters: monitor for maternal acidosis.
It is not known whether dorzolamide is excreted in human milk. Systemic absorption is low (≈4%). Because many drugs are excreted in human milk, caution should be exercised when administered to a nursing woman. M/P ratio not available. Consider the developmental and health benefits of breastfeeding along with the mother's clinical need for dorzolamide and potential adverse effects on the breastfed child.
It is not known if brinzolamide is excreted in human milk. In animal studies, brinzolamide was detected in milk of lactating rats. Caution is advised; consider risk vs benefit. M/P ratio: unknown.
No dose adjustment is recommended. The systemic absorption of topical dorzolamide is low (≈4%) and pharmacokinetics are not expected to change significantly in pregnancy. Use the standard adult dose: one drop in the affected eye(s) three times daily.
No specific dose adjustments recommended; however, due to potential for increased systemic absorption during pregnancy (increased blood volume and ocular changes), monitor intraocular pressure closely. Use the lowest effective dose. Pharmacokinetic changes: unknown; adjust based on clinical response.
Dorzolamide is a topical carbonic anhydrase inhibitor used for elevated intraocular pressure. It can cause metabolic acidosis due to systemic absorption, especially in patients with renal impairment. Avoid use with oral carbonic anhydrase inhibitors to prevent additive systemic effects. Monitor for corneal edema in patients with compromised corneas. The drug may cause transient blurred vision; apply pressure over the nasolacrimal duct to minimize systemic absorption.
AZOPT (brinzolamide ophthalmic suspension) is a carbonic anhydrase inhibitor used for lowering intraocular pressure in ocular hypertension or open-angle glaucoma. Shake well before use; may cause transient blurred vision. Use with caution in sulfonamide allergy patients. Monitor for corneal edema and electrolyte disturbances in prolonged use.
Instill one drop in the affected eye(s) three times daily, as directed.,Wash hands before and after use. Avoid touching the dropper tip to any surface.,If using other eye drops, wait at least 5 minutes between administrations.,Do not wear contact lenses during treatment; may discolor soft contact lenses.,Report eye pain, redness, vision changes, or signs of allergy (rash, itching).,May cause temporary blurred vision; do not drive or operate machinery until vision clears.,Store at room temperature, tightly closed, and protect from light.
Shake the bottle vigorously before each use.,Remove contact lenses before instilling and wait at least 15 minutes before reinserting.,Apply pressure to the tear duct (punctal occlusion) for 1 minute after instillation to reduce systemic absorption.,Do not touch the dropper tip to any surface to avoid contamination.,May cause temporary blurred vision; avoid driving or operating machinery until vision clears.,Report any eye pain, redness, or vision changes to your healthcare provider.
"Dorzolamide, a carbonic anhydrase inhibitor used for glaucoma, may theoretically inhibit the metabolism of cobicistat, a pharmacokinetic enhancer used in HIV therapy, by competing for hepatic CYP3A4 enzymes or altering renal clearance. This interaction could lead to increased cobicistat exposure, potentiating its adverse effects such as nephrotoxicity or gastrointestinal disturbances. However, clinically relevant interactions are unlikely due to dorzolamide's limited systemic absorption following ophthalmic administration."
"Chlorthalidone, a thiazide-like diuretic, and dorzolamide, a carbonic anhydrase inhibitor, both act to reduce bicarbonate reabsorption in the kidney, leading to enhanced electrolyte excretion, particularly potassium and bicarbonate. This synergistic effect can cause additive hypokalemia and metabolic acidosis, increasing the risk of cardiac arrhythmias and renal dysfunction. Concurrent use may also potentiate hypotensive effects due to volume depletion and vasodilation."
"Concurrent administration of dorzolamide, a carbonic anhydrase inhibitor, may reduce the urinary acidification necessary for methenamine's conversion to formaldehyde, the active antibacterial agent. This alkalinization of urine pH impairs the therapeutic efficacy of methenamine in treating urinary tract infections. Clinically, this can result in suboptimal bactericidal activity and potential treatment failure."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about DORZOLAMIDE HYDROCHLORIDE vs AZOPT, answered by our medical review team.
DORZOLAMIDE HYDROCHLORIDE is a Carbonic Anhydrase Inhibitor that works by Dorzolamide hydrochloride is a carbonic anhydrase II inhibitor. By inhibiting carbonic anhydrase in the ciliary processes of the eye, it reduces aqueous humor secretion, thereby lowering intraocular pressure.. AZOPT is a Carbonic Anhydrase Inhibitor that works by Carbonic anhydrase inhibitor; inhibits carbonic anhydrase II (CA-II) in ciliary processes, reducing aqueous humor secretion and intraocular pressure.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between DORZOLAMIDE HYDROCHLORIDE and AZOPT depend on the specific clinical indication. These are both Carbonic Anhydrase Inhibitor agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of DORZOLAMIDE HYDROCHLORIDE is: One drop of 2% solution in the affected eye(s) three times daily.. The standard adult dose of AZOPT is: One drop in the affected eye(s) twice daily. Instill at least 10 minutes apart from other ophthalmic medications.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between DORZOLAMIDE HYDROCHLORIDE and AZOPT in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. DORZOLAMIDE HYDROCHLORIDE is classified as Category C. Dorzolamide is a carbonic anhydrase inhibitor. No adequate and well-controlled studies in pregnant women. In animal studies, no teratogenic effects at doses up to 2.5 mg/kg/day (ra. AZOPT is classified as Category C. Pregnancy Category C. No adequate studies in pregnant women. In animal studies, brinzolamide (active ingredient) showed no teratogenic effects at oral doses up to 6 mg/kg/day in ra. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.