α-Agonist

α AGONIST (SYMPATHOMIMETICS):

  1. Clonidine (0.12% & 0.25%)
  2. Apraclonidine (0.5%)
  3. Brimonidine (0.2%):[NEURO PROTECTIVE]
  4. Dipivefrine
  5. Epinenephrine

 

Mechanism Of Action :

Mechanism:1

α receptor stimulation

increased aqueous outflow

reduced IOP


Mechanism:2

stimulation of α receptor in ciliary body

reduced aqueous humor production

reduced IOP


Mechanism:3 (Brimonidine)

selective α2 agonist

decreased aqueous production & increased uveoscleral outflow

reduced IOP


 

 

Duration of Action: 12 hours

Frequency: BD

INDICATIONS:

  1. Used in glaucoma if not controlled with β blockers
  2. After Nd:YAG laser iridotomy – increased pigment dispersion – raised IOP – α agonist are given
  3. Laser trabeculoplasty & post capsulotomy.

 

SIDE EFFECTS :

  1. SYSTEMIC : Hypertension, tachycardia, headache, palpitation, tremors, nervousness & anxiety.
  2. LOCAL : burning sensation, conjunctival hyperemia, conjunctival pigmentation, allergic blepharo conjunctivitis, mydriasis, cystoids macular edema.