Primary Angle-Closure Glaucoma Drug Summary

Last updated: 09 March 2026

Adrenergic Agonists

Drug Available
Strength		 Dosage Remarks
Alpha2-selective Adrenergic Agonists
Apraclonidine 0.5%, 1% ophthalmic solution Instill 1-2 drops 8 hourly Adverse Reactions
  • Ophthalmologic effects: Conjunctival hyperemia, lid retraction, mydriasis, blurred vision, conjunctivitis, allergic reactions especially with long-term use (characterized by ocular pruritus, increased lacrimation, hyperemia, edema of lids and conjunctivae)
  • Systemic effects: Somnolence, fatigue, headache, hypotension, hypertension, dizziness, dry mouth
  • Apraclonidine may induce tachyphylaxis
Special Instructions
  • Avoid in children <12 years old and in patients on oral monoamine oxidase inhibitors
  • Use with caution in patients with severe CV disease (including hypertension), cerebral insufficiency, orthostatic hypotension, those with history of vasovagal attacks, and those performing tasks which require mental alertness (eg driving, operating machineries)
Brimonidine 0.1%, 0.15%, 0.2% ophthalmic solution Instill 1 drop 8-12 hourly

Beta-Blockers

Drug Available
Strength		 Dosage Remarks
Beta1-selective Beta-blocker
Betaxolol 0.5% ophthalmic solution Instill 1 drop 12 hourly Adverse Reactions
  • Ophthalmologic effects: Ocular irritation (including hypersensitivity), keratitis, blepharitis, photophobia, decreased corneal sensitivity, ptosis, diplopia, visual disturbances
  • Systemic effects: Bradycardia, arrhythmias, heart failure (HF), hypotension, bronchospasm, dyspnea, depression, headache, dizziness
Special Instructions
  • Contraindicated in patients with bronchial asthma, severe chronic obstructive pulmonary disease (COPD), 2nd- and 3rd-degree heart block, sinus node dysfunction, sinus bradycardia, uncompensated HF
  • Use with caution in patients with mild-moderate COPD, 1st-degree heart block, DM (since hypoglycemia may be potentiated and/or mask signs and symptoms)
0.25% ophthalmic suspension Instill 1-2 drops 12 hourly
Non-selective Beta-blockers
Befunolol 0.25%, 0.5%, 1% ophthalmic solution Instill 1 drop 12 hourly
Carteolol 1%, 2% ophthalmic
solution		 Instill 1 drop 12 hourly
Levobunolol 0.25%, 0.5% ophthalmic solution Instill 1-2 drops 12-24 hourly
Metipranolol 0.1%, 0.3% ophthalmic
solution		 Instill 1 drop 12 hourly
Timolol 0.25%, 0.5% ophthalmic solution Instill 1 drop 12 hourly
0.1%, 0.25%, 0.5% ophthalmic gel Instill 1 drop 24 hourly

Carbonic Anhydrase Inhibitors (Oral)

Drug Dosage Remarks
Acetazolamide 250 mg PO 4 hourly Adverse Reactions
  • Other effects (malaise, fatigue, headache, depression, excitement, weight loss, GI disturbances)
  • At high doses: Drowsiness, paresthesia
  • Rarely: Blood dyscrasias; severe metabolic acidosis has occasionally been reported in the elderly and in DM patients
Special Instructions
  • Contraindicated in patients with depressed Na and K levels, hyperchloremic acidosis, Addison’s disease, adrenocortical insufficiency, marked hepatic and renal dysfunction, in chronic angle-closure glaucoma since it may mask the deterioration of the condition
  • Use with caution in patients with DM, hepatic and renal impairment, pulmonary obstruction, conditions predisposing to metabolic acidosis
  • Use with caution in patients on steroid and systemic hypertension diuretic therapy due to potential for hypokalemia
  • Monitor serum electrolytes and blood counts if used long-term
Methazolamide 50-100 mg PO 8-12 hourly

Carbonic Anhydrase Inhibitors (Topical)

Drug Available
Strength		 Dosage Remarks
Brinzolamide 1% ophthalmic suspension Instill 1 drop 8-12 hourly Adverse Reactions
  • Ophthalmologic effects: Conjunctivitis, keratitis, burning or stinging sensation, eyelid inflammation or irritation, blurred vision
  • If absorbed systemically, may result in adverse reactions of oral carbonic anhydrase inhibitors
Special Instructions
  • Avoid use in patients with severe renal impairment or with previous history of severe allergic reaction to sulfonamides
  • Use with caution in patients with low endothelial cell counts (potential for developing corneal edema) or hepatic impairment
Dorzolamide 2% ophthalmic solution Instill 1 drop 8 hourly
Decrease frequency to 12 hourly if used with a beta-blocker

Parasympathomimetics

Drug Available
Strength		 Dosage Remarks
Direct-acting Parasympathomimetics
Carbachol 0.75%, 1.5%, 3% ophthalmic solution Instill 1-2 drops up to 8 hourly Adverse Reactions
  • Ophthalmologic effects: Ciliary spasm, blurred vision, lacrimation, brow ache, ocular pain and irritation, myopia, headache
  • Ecothiopate ocular effects: Acute iritis, retinal detachment or precipitation of acute glaucoma may occasionally occur; lens opacities or iris cysts may develop on prolonged treatment
  • Systemic effects after ophthalmic use are thought to be rare
Special Instructions
  • Contraindicated in patients with acute inflammatory disease of the anterior chamber of the eyes, acute iritis, acute uveitis, some forms of secondary glaucoma
  • Use with extreme caution in patients with history of retinal detachment, young patients with myopia, patients with corneal and conjunctival damage
  • Use with extreme caution during night driving or when undertaking hazardous tasks under poor illumination
  • For better tolerance, patients given Ecothiopate should be initially started on the 0.03% strength for a short period
  • In patients receiving Ecothiopate, Phenylephrine drops may be given simultaneously to prevent or reduce development of iris cysts
Pilocarpine 0.5%, 1%, 2%, 4% ophthalmic solution Instill 1-2 drops 6-8 hourly
or 1 drop (1%, 2%, 4% ophthalmic solution) every 5 minutes until miosis is achieved in acute closed-angle glaucoma
4% ophthalmic gel Apply 24 hourly at bedtime

Prostaglandin Analogues

Drug Available
Strength		 Dosage Remarks
Bimatoprost 0.01%, 0.03%
ophthalmic solution		 Instill 1 drop 24 hourly in the evening Adverse Reactions
  • Ophthalmologic effects: Conjunctival hyperemia, ocular pruritus, blurred vision, burning and stinging, foreign body sensation, iritis, uveitis, macular edema, increase in brown pigmentation of the iris (may be permanent in some patients) and lengthening and/or thickening of eyelashes
  • Systemic effects: Headache, dizziness, myalgia, arthralgia, rash
Special Instructions
  • Use with caution in patients at risk for macular edema, in patients with intraocular inflammation, in aphakic patients
  • Remove contact lens prior to application
  • Prostaglandin analogues (except Unoprostone): Do not exceed once-daily dosage (frequent administration has been shown to decrease IOP lowering effect)
Latanoprost 0.005%
ophthalmic solution		 Instill 1 drop 24 hourly in the evening
Latanoprostene
bunod		 0.024%
ophthalmic solution		 Instill 1 drop 24 hourly in the evening
Tafluprost 0.0015%
ophthalmic solution		 Instill 1 drop 24 hourly in the evening
Travoprost1 0.003%
0.004%
ophthalmic solution		 Instill 1 drop 24 hourly in the evening
Unoprostone
(Unoprostone
isopropyl)		 0.12%, 0.15%
ophthalmic solution		 Instill 1 drop 12 hourly
1Benzalkonium chloride (BAK)-free preparations are also available.

Other Antiglaucoma Agents

Drug Dosage Remarks
Hyperosmotic Agents
Glycerol Reduction of corneal edema:
Instill 1-2 drops
prior to eye exam 		Adverse Reactions
  • Oral Glycerol: GI effects (nausea/vomiting, diarrhea); Other effects (headache, thirst, dizziness, mental confusion, arrhythmias, circulatory overload)
  • Topical Glycerol: Ocular effect (pain or irritation on instillation)
Special Instructions
  • Oral Glycerol: Use with caution in patients with DM, those at risk of circulatory overload (eg patients with HF, hypervolemia and renal disease), in dehydrated patients
  • Topical Glycerol: A local anesthetic may be used prior to application
Reduction of IOP:
1-1.8 g/kg/dose PO
(as 50% solution)
1-1.5 hrs
preoperatively
or
300-500 mL IV infusion over
45-90 minutes
Mannitol 0.25-2 g/kg IV infusion (of a
15-25% solution) over
30-60 minutes		 Adverse Reactions
  • Metabolic effects (fluid and electrolyte imbalance, circulatory overload, acidosis); GI effects (nausea/vomiting); CV effects (tachycardia, chest pain, hypotension or hypertension); Other effects (thirst, dizziness, headache, fever, chills, dehydration, blurred vision, urticaria; hypersensitivity reactions have occurred)
Special Instructions
  • For short-term use in reduction of IOP
  • Contraindicated in patients with HF, intracranial bleeding pulmonary congestion and severe renal impairment
  • Use with caution in patients with underlying renal disease
  • Patients should be observed for signs of fluid and electrolyte imbalance, and renal function monitored
Rho Kinase Inhibitor
Netarsudil Instill 1 drop (0.02%
ophthalmic solution) into affected eye(s) 24 hourly in the evening 		Adverse Reactions
  • Ophthalmologic effects (conjunctival hyperemia, conjunctival hemorrhage, corneal deposits/verticillata); Other effect (application site pain)
Special Instructions
  • Remove contact lens prior to application

Combination Products*

Drug Available Strength Dosage
Adrenergic Agonist and Beta-blocker
Brimonidine/Timolol Brimonidine 2 mg/Timolol 5 mg Instill 1 drop into affected eye(s) 12 hourly
Beta-blocker and Parasympathomimetic 
Timolol/Pilocarpine  Timolol 5 mg/Pilocarpine 20 mg or 40 mg  Instill 1 drop into affected eye(s) 12 hourly 
Carbonic Anhydrase Inhibitor (Topical) and Beta-blocker
Brinzolamide/Timolol Brinzolamide 10 mg/Timolol 5 mg Instill 1 drop into affected eye(s) 12 hourly
Dorzolamide/Timolol Dorzolamide 20 mg/Timolol 5 mg Instill 1 drop into affected eye(s) 12 hourly
Prostaglandin Analogue and Beta-blocker
Brimatoprost/Timolol Brimatoprost 0.3 mg/Timolol 5 mg  Instill 1 drop into affected eye(s) 24 hourly in the morning
Latanoprost/Timolol Latanoprost 50 mcg/Timolol 5 mg Instill 1 drop into affected eye(s) 24 hourly
Tafluprost/Timolol Tafluprost 15 mcg/Timolol 5 mg  Instill 1 drop into affected eye(s) 24 hourly
Travoprost/Timolol1 Travoprost 0.04 mg/Timolol 5 mg  Instill 1 drop into affected eye(s) 24 hourly (morning or evening; administer at the same time each day)
Other Combinations
Brinzolamide/Brimonidine Brinzolamide 10 mg/Brimonidine 2 mg Instill 1 drop into affected eye(s) 8-12 hourly
Netarsudil/Latanoprost Netarsudil 0.02%/Latanoprost 0.005%  Instill 1 drop into affected eye(s) 24 hourly in the evening
*For adverse reactions and special instructions, please see remarks section of each individual drug component or refer to the latest MIMS for the specific formulations and prescribing information.
1BAK-free preparations are also available.

Disclaimer

All dosage recommendations are for non-pregnant and non-breastfeeding women, and non-elderly adults with normal renal and hepatic function unless otherwise stated.  
Not all products are available or approved for above use in all countries.  
Products listed in the Drug Summary are based on indications stated in the locally approved product monographs.   
Please refer to local product monographs in Related MIMS Drugs for country-specific prescribing information.