Comparative Pharmacology
Head-to-head clinical analysis: BRIMONIDINE TARTRATE TIMOLOL MALEATE versus INDERAL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BRIMONIDINE TARTRATE TIMOLOL MALEATE versus INDERAL.
BRIMONIDINE TARTRATE; TIMOLOL MALEATE vs INDERAL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Brimonidine is a selective alpha-2 adrenergic receptor agonist that reduces aqueous humor production and increases uveoscleral outflow. Timolol is a non-selective beta-adrenergic receptor blocker that decreases aqueous humor production by inhibiting beta-2 receptors in the ciliary epithelium.
Nonselective beta-adrenergic receptor antagonist; competes with catecholamines for binding at beta-1 and beta-2 receptors, decreasing heart rate, myocardial contractility, and blood pressure.
One drop of the fixed combination (0.2% brimonidine/0.5% timolol) in the affected eye(s) twice daily, approximately 12 hours apart.
Hypertension: 40 mg orally twice daily; increase as needed up to 640 mg/day. Angina: 80-320 mg orally daily in divided doses. Migraine prophylaxis: 80 mg orally daily in divided doses; up to 160-240 mg/day. Arrhythmias: 10-30 mg orally 3-4 times daily. IV: 1-3 mg IV bolus at 1 mg/min; may repeat after 2 min.
None Documented
None Documented
Brimonidine: ~3 hours (terminal); timolol: ~4–6 hours (terminal). Clinical context: allows twice-daily dosing for brimonidine/timolol combination.
3-6 hours (terminal). Clinical context: half-life increases with chronic dosing due to saturable hepatic metabolism; in cirrhosis, half-life may be prolonged to 10-23 hours.
Brimonidine: primarily renal (74% as unchanged drug); timolol: renal (20% unchanged, remainder as metabolites) and fecal (small amount).
Renal: 96-99% as metabolites (active 4-hydroxypropranolol and conjugates), <1% unchanged. Biliary/fecal: minimal.
Category A/B
Category C
Beta-Blocker
Beta-Blocker