The drug atlas
Ophthalmology/α₂-agonist (glaucoma)

α₂-agonist eye drops

also: brimonidine · apraclonidine · sympathomimetic glaucoma

Overview

Glaucoma drops that both reduce production and increase outflow. Note: brimonidine is an α₂-agonist (a common labelling error is "α₁").

Mechanism

Selective α₂-adrenoceptor agonists → REDUCE aqueous production AND increase uveoscleral outflow → lower IOP. (Not α₁ — the legacy mislabel.)

Indications

  • Open-angle glaucoma (add-on / β-blocker-intolerant)
  • Acute angle-closure glaucoma (apraclonidine in the combination)

The agents

Brimonidineα₂-agonist

BD

Allergic conjunctivitis is common; avoid with MAOIs/TCAs.

Apraclonidineα₂-agonist

Short-term / peri-laser; acute AACG combination.

Adverse effects

Ocular allergy / hyperaemiacommon

Common cause of discontinuation.

Dry mouth, drowsiness/fatiguecommon
Apnoea/CNS depression in infantsserious

Avoid in young children.

Cautions & contraindications

MAOIs / TCAsall

Sympathomimetic interaction.

Young childrenpaediatric

CNS depression/apnoea.

Interactions

  • MAOIs, TCAs, CNS depressants

Monitoring & kinetics

IOP; ocular allergy

Topical BD.

Source: NICE NG81 — Glaucoma · BNF — Sympathomimetics (eye)