Brimonidine

Brand Names: Alphagan, Alphagan P

Drug Class: Alpha-2 adrenergic receptor agonist

Overview

Brimonidine is a selective alpha-2 adrenergic receptor agonist used primarily to lower intraocular pressure in patients with open-angle glaucoma or ocular hypertension. It reduces aqueous humor production and increases uveoscleral outflow.

Mechanism of Action

Brimonidine selectively stimulates alpha-2 adrenergic receptors in the eye, which reduces aqueous humor production and increases uveoscleral outflow, thereby lowering intraocular pressure.

Indications

  • Reduction of intraocular pressure in patients with open-angle glaucoma
  • Ocular hypertension
  • Management of facial erythema of rosacea (topical gel formulation)

Dosage

Ophthalmic solution: One drop in affected eye(s) three times daily, approximately 8 hours apart. Topical gel for rosacea: Apply thin layer to affected areas once daily.

Contraindications

  • Hypersensitivity to brimonidine or any component of the formulation
  • Monoamine oxidase inhibitor therapy
  • Infants and children under 2 years of age (ophthalmic solution)
  • Patients with hypersensitivity to brimonidine tartrate

Side Effects

  • Ocular hyperemia
  • Ocular pruritus
  • Burning/stinging sensation
  • Foreign body sensation
  • Dry mouth
  • Headache
  • Blurred vision
  • Fatigue/drowsiness
  • Ocular allergic reactions
  • Conjunctival follicles

Interactions

  • CNS depressants (additive sedative effects)
  • Antihypertensive agents (additive hypotensive effects)
  • Tricyclic antidepressants (may reduce brimonidine's effect)
  • Monoamine oxidase inhibitors (contraindicated)