Comparative Pharmacology
Head-to-head clinical analysis: BRIMONIDINE TARTRATE TIMOLOL MALEATE versus COREG.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BRIMONIDINE TARTRATE TIMOLOL MALEATE versus COREG.
BRIMONIDINE TARTRATE; TIMOLOL MALEATE vs COREG
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.
Carvedilol is a nonselective beta-blocker with alpha1-blocking activity. It competitively blocks beta1, beta2, and alpha1 adrenergic receptors, leading to decreased cardiac output, reduced sympathetic tone, and vasodilation. It also has antioxidant and anti-proliferative properties.
One drop of the fixed combination (0.2% brimonidine/0.5% timolol) in the affected eye(s) twice daily, approximately 12 hours apart.
Heart failure: Start 3.125 mg orally twice daily; titrate up to target 25 mg twice daily as tolerated. Hypertension: Start 6.25 mg orally twice daily; increase to max 50 mg twice daily. Post-MI LV dysfunction: Start 3.125-6.25 mg orally twice daily; titrate to target 25 mg twice daily.
None Documented
None Documented
Brimonidine: ~3 hours (terminal); timolol: ~4–6 hours (terminal). Clinical context: allows twice-daily dosing for brimonidine/timolol combination.
Terminal elimination half-life is 7-10 hours in most patients, but may be prolonged in severe hepatic impairment (up to 14-18 hours). The half-life is not significantly altered in renal impairment.
Brimonidine: primarily renal (74% as unchanged drug); timolol: renal (20% unchanged, remainder as metabolites) and fecal (small amount).
Renal excretion of unchanged drug and metabolites accounts for approximately 16% of the dose; fecal excretion accounts for about 84% (mainly as metabolites). Less than 2% is excreted unchanged in urine.
Category A/B
Category C
Beta-Blocker
Beta-Blocker