Side effects of sympathomimetic agonist (α2 agonist) glaucoma medication: drowsiness, dry mouth, lethargy, fatigue, contraindications in children

👁 Side Effects of α2 Agonists for Glaucoma (e.g., Brimonidine)

α2 agonists such as Brimonidine (Alphagan-P, Bridin-T) and
Apraclonidine (Iopidine) are commonly used to lower IOP
by both reducing aqueous humor production and enhancing uveoscleral outflow.

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📌 Mechanism

ActionEffect

α2 agonist

↓ Aqueous production + ↑ Uveoscleral outflow

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👁 Ocular Side Effects

1. Allergic follicular conjunctivitis, contact dermatitis
2. Mydriasis, eyelid tightness, conjunctival blanching
   → Caused by α1 cross-activation

 

 

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💢 Systemic Side Effects

TypeNotes

CNS depression	Drowsiness, fatigue, sedation, dry mouth
Pediatric caution

• Contraindicated under age 5
• Avoid if under 15 due to sleepiness risk

✅ Apraclonidine has less CNS effect due to low lipid solubility

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✅ Summary

• Frequent allergic reactions
• CNS side effects → avoid in children under 15
• Brimonidine is effective but caution needed in younger patients