indication

For the lowering of intraocular pressure in patients with open-angle glaucoma or ocular hypertension.

pharmacology

Brimonidine significantly lowers intraocular pressure with minimal effects on cardiovascular and pulmonary parameters. It lowers intraocular pressure by reducing aqueous humor production and increasing uveoscleral outflow.

mechanism of action

Brimonidine is an alpha adrenergic receptor agonist (primarily alpha-2). It has a peak ocular hypotensive effect occurring at two hours post-dosing. Fluorophotometric studies in animals and humans suggest that Brimonidine has a dual mechanism of action by reducing aqueous humor production and increasing uveoscleral outflow.

toxicity

Oral LD₅₀ is 50 mg/kg in mice and 100 mg/kg in rats.

biotransformation

Metabolized primarily by the liver.

absorption

Minimal systemic absorption occurs after ocular insertion.

half life

2 hours

route of elimination

It is metabolized primarily by the liver. Urinary excretion is the major route of elimination of the drug and its metabolites.

drug interactions

Droperidol: Droperidol may enhance the CNS depressant effect of brimonidine. Consider therapy modification.

Isocarboxazid: MAO Inhibitors like isocarboxazid may enhance the hypertensive effect of Alpha2-Agonists (Ophthalmic). The concomitant use of monoamine oxidase inhibitors and ophthalmic alpha2 agonists is contraindicated.

Linezolid: MAO Inhibitors like linezolid may enhance the hypertensive effect of Alpha2-Agonists (Ophthalmic). The concomitant use of monoamine oxidase inhibitors and ophthalmic alpha2 agonists is contraindicated.

Methotrimeprazine: Brimonidine may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of brimonidine. Consider therapy modification.

Moclobemide: MAO Inhibitors like moclobemide may enhance the hypertensive effect of Alpha2-Agonists (Ophthalmic). The concomitant use of monoamine oxidase inhibitors and ophthalmic alpha2 agonists is contraindicated.

Phenelzine: MAO Inhibitors like phenelzine may enhance the hypertensive effect of Alpha2-Agonists (Ophthalmic). The concomitant use of monoamine oxidase inhibitors and ophthalmic alpha2 agonists is contraindicated.

Procarbazine: MAO Inhibitors like procarbazine may enhance the hypertensive effect of Alpha2-Agonists (Ophthalmic). The concomitant use of monoamine oxidase inhibitors and ophthalmic alpha2 agonists is contraindicated.

Rasagiline: MAO Inhibitors like rasagiline may enhance the hypertensive effect of Alpha2-Agonists (Ophthalmic). The concomitant use of monoamine oxidase inhibitors and ophthalmic alpha2 agonists is contraindicated.

Selegiline: MAO Inhibitors like selegiline may enhance the hypertensive effect of Alpha2-Agonists (Ophthalmic). The concomitant use of monoamine oxidase inhibitors and ophthalmic alpha2 agonists is contraindicated.

Tranylcypromine: The MAO inhibitor, Tranylcypromine, may increase the vasopressor effect of the alpha2-agonist, Brimonidine. Concomitant therapy is contraindicated.

Treprostinil: Additive hypotensive effect. Monitor antihypertensive therapy during concomitant use.