Comprehensive medication guide to Dorzolamide including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$15 copay at Tier 1 on most commercial plans; $15–$45 at Tier 2. Medicare Part D plans generally cover dorzolamide as a preferred generic. Prior authorization is rarely required for the generic formulation.
Estimated Cash Pricing
$58 average retail for generic dorzolamide 2% 10mL; as low as $15.19 with a GoodRx coupon or under $14 with SingleCare at participating pharmacies for a standard bottle.
Medfinder Findability Score
82/100
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Dorzolamide is a prescription ophthalmic solution used to lower elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. It belongs to the carbonic anhydrase inhibitor (CAI) drug class and was originally sold under the brand name Trusopt, developed by Merck. The brand-name Trusopt has been discontinued in the U.S. market; dorzolamide is now available as a generic medication only.
Approved by the FDA in December 1994, dorzolamide was historically significant as the first drug ever developed using structure-based drug design — a technique that marked a turning point in pharmaceutical discovery. The drug is available as a 2% ophthalmic solution dispensed in a 10mL bottle, and also in a fixed-dose combination with timolol (generic Cosopt, also available preservative-free as Cosopt PF equivalent).
In 2023, dorzolamide was the 190th most commonly prescribed medication in the United States, with over 2 million prescriptions. It is used both as monotherapy and as an add-on to prostaglandin analogs or beta-blockers when single-agent therapy provides insufficient IOP lowering.
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Dorzolamide lowers intraocular pressure by inhibiting carbonic anhydrase II (CA-II), an enzyme in the ciliary body of the eye that plays a critical role in aqueous humor production. Carbonic anhydrase catalyzes the conversion of carbon dioxide and water into bicarbonate and hydrogen ions — a reaction that drives the sodium-hydrogen exchange necessary to produce aqueous fluid. By blocking CA-II, dorzolamide reduces bicarbonate production and decreases the secretion of aqueous humor.
Dorzolamide has approximately 4,000-fold greater affinity for CA-II than for CA-I, making it highly selective. This selectivity helps minimize systemic effects, though some absorption does occur through the nasolacrimal duct. At steady state, dorzolamide lowers IOP by approximately 20%. Effects begin within about 3 hours of instillation and last approximately 8 hours, necessitating three-times-daily dosing.
Unlike prostaglandin analogs (which increase aqueous outflow) or beta-blockers (which reduce aqueous production via a different pathway), dorzolamide acts directly on the enzymatic mechanism of fluid secretion. It is often used in combination with these other classes to achieve additive IOP reduction.
2% — ophthalmic solution
Standard concentration; 20 mg/mL (22.3 mg/mL as hydrochloride salt); 10 mL bottle; dosed 1 drop TID
2%/0.5% — ophthalmic solution (combination with timolol)
Dorzolamide/timolol combination (generic Cosopt); dosed 1 drop BID; also available preservative-free (Cosopt PF equivalent)
As of 2026, dorzolamide is not on the FDA's active drug shortage list. Multiple generic manufacturers produce dorzolamide 2% ophthalmic solution following the discontinuation of brand-name Trusopt, which generally supports supply availability. Most major pharmacy chains (CVS, Walgreens, Walmart, Costco) and mail-order pharmacies carry generic dorzolamide routinely.
However, local stock-outs do occur — particularly at smaller or independent pharmacies, or when a specific generic manufacturer experiences supply disruptions. Patients who rely on dorzolamide for glaucoma management should not wait until they're out of medication to refill. Refilling with 1-2 weeks remaining provides a buffer to find stock if your primary pharmacy is temporarily out.
If your pharmacy is out of stock, medfinder can contact pharmacies near you to find which ones have dorzolamide in stock, saving you from making multiple phone calls.
Dorzolamide is not a controlled substance and has no DEA scheduling requirements. Any licensed prescriber with standard prescribing authority can write a prescription for it. In practice, the following provider types most commonly prescribe and manage dorzolamide therapy:
Telehealth availability is limited for initial prescriptions because glaucoma diagnosis requires in-person intraocular pressure measurement by tonometry. However, stable patients may be able to receive prescription renewals via telehealth in some states. Confirm telehealth availability with your specific provider.
No. Dorzolamide is not a controlled substance. It has no DEA schedule and is not subject to any federal controlled substance restrictions. Any licensed prescriber with standard prescribing authority can write a prescription for dorzolamide without a DEA number, without using special prescription forms, and without any limitations on the number of refills.
Dorzolamide prescriptions can be transferred to any pharmacy without restriction, filled in 30- or 90-day quantities, and refilled as needed according to your doctor's instructions. There are no additional regulatory steps for patients or pharmacists beyond a standard prescription.
The most frequently reported side effects of dorzolamide are local (in or around the eye) and typically occur immediately after instillation:
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Brinzolamide (Azopt)
Same drug class (carbonic anhydrase inhibitor); suspension vs. solution; pH closer to tears causes less stinging; also TID; also a sulfonamide
Latanoprost (Xalatan)
Prostaglandin analog; first-line agent for most patients; once-daily dosing; lowers IOP 25-30%; may cause iris pigmentation changes
Timolol (Timoptic)
Beta-blocker; reduces aqueous production via different mechanism; QD or BID; contraindicated in asthma/COPD/bradycardia
Brimonidine (Alphagan P)
Alpha-2 agonist; reduces production and increases outflow; BID-TID; useful when beta-blockers are contraindicated
Bimatoprost (Lumigan)
Prostaglandin analog; once daily; potent IOP lowering; may increase eyelash growth and cause iris color change
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Acetazolamide (Diamox)
majorOral carbonic anhydrase inhibitor; concurrent use is contraindicated due to additive systemic CA inhibition — risk of metabolic acidosis and electrolyte disturbances
Methazolamide (Neptazane)
majorOral carbonic anhydrase inhibitor; same contraindication as acetazolamide — do not use concurrently
Zonisamide (Zonegran)
moderateAnticonvulsant with carbonic anhydrase inhibiting properties; concurrent use may increase systemic CA inhibition
High-dose salicylates (aspirin)
moderatePotential acid-base and electrolyte disturbances with systemic CA inhibition; low-dose aspirin (81 mg) is generally safe
Oral beta-blockers (atenolol, metoprolol)
moderateRelevant for dorzolamide/timolol combination only; additive bradycardia and blood pressure lowering
Calcium channel blockers (nifedipine, diltiazem)
moderateRelevant for dorzolamide/timolol combination only; additive cardiovascular effects
Dorzolamide is a well-established, affordable generic medication for the management of open-angle glaucoma and ocular hypertension. As the only topical carbonic anhydrase inhibitor available in solution form, it fills an important role in glaucoma therapy — particularly as an add-on agent for patients who need additional IOP lowering beyond their primary medication.
While the brand-name Trusopt is no longer available, the generic dorzolamide is widely stocked and cost-effective. Patients using GoodRx or SingleCare coupons can typically purchase it for $14-$15 per bottle — a significant savings from the $58 retail price. Most insurance plans cover it at low-tier copays.
If you're struggling to find dorzolamide at your pharmacy, medfinder can contact pharmacies near you to find which ones have your medication in stock — saving you time and helping ensure you never miss a critical dose of your glaucoma therapy.
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