Dorzolamide and Timolol, Eye

Miotic, Antiglaucoma Preps · Beta-blocker/Carbonic anhydrase inhibitor

Indications

Raised intraocular pressure in open angle glaucoma or psuedoexfoliation glaucoma when beta blocker monotherapy is inadequate.

Dosage

Adults: 1 drop in the affected eye(s) twice daily. Children: Not recommended.

Adverse Effects

Local irritation, taste perversion, corneal erosion, blurred vision, urolithiasis, possible systemic effects, sinusitis, conjunctival infection, headache, nausea, asthenia, fatigue, systemic beta blocker and sulfonamide effects.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Contraindicated in pregnancy. Lactation: Contraindicated or not recommended. Contraindications: History of bronchial asthma, severe COPD, sinus bradycardia, 2nd or 3rd degree AV block, SA block, sick sinus syndrome, cardiac failure, cardiogenic shock, severe renal impairment, hyperchloraemic acidosis. Soft contact lenses. Precautions: Prinzmetal's angina, severe peripheral and central vascular disorders, hypotension, uncontrolled heart failure, history of severe cardiac disease, hepatic impairment, diabetes, hyperthyroidism, Myasthaenia gravis, history of renal calculi, hypersensitivity to sulphonamides. Withdraw gradually. Mild to moderate COPD, corneal disease, history of intra-ocular surgery. Remove soft contact lenses; wait 15 min before reinserting.

Interactions

Leave interval of 10 min, if applying other topical ophthalmic agents. Antiarrhythmics, adrenaline, antihypertensives, SSRIs, other CYP2D6 inhibitors, digoxin, narcotics, MAOIs, cholinergic agents, other B blockers, oral carbonic anhydrase inhibitors, anaesthesia, parasympathomimetics, antidiabetic agents.

Advice to Patient

Wash hands properly before use. Remove contact lenses before use. Wait 15 minutes before reinserting. To instill medication into eyes, tilt head back, look upward, instill drops into the eye. Close eye and roll eyeball in all directions. Do not blink for 30 seconds. Apply gentle pressure to inner corner of eye for 30 seconds. Contact prescriber if there is eye pain; eye infection; redness, burning, watering, puffiness around eyes; changes in vision; unusual reaction; no improvement or worsening of condition. Avoid touching tip of applicator with eye. Do not share medication with anyone else. Wait 5 minutes before instilling any other medication.

Pharmacokinetics

DORZOLAMIDE: Onset: 2 hrs. Duration: 8-12 hrs. Absorption: Absorbed via the cornea and stroma. Metabolism: Hepatic. Half-life elimination: 120 days. Time to peak: 2 hrs. Excretion: Urine (80%). TIMOLOL: Onset: 30 mins. Duration: 12-24 hrs. Absorption: Significant systemic absorption when administered to the eye. Metabolism: Hepatic. Half-life elimination: 4 hrs. Time to peak: 1-2 hrs. Excretion: Urine (mainly).

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.