Pharmacological therapy : alpha 2 - adrenergic agonists

Question 1

Two types of alpha-2 adrenergic agonsits

Answer 1

1. Brimonidine
2. Apraclonidine
   = decrease IOP = reduce aq humour

Question 2

Selectivity of adrenergic agonsits

Answer 2

Brimonidine > selectivity than apraconidine

= also has dual MOA - increase uveoscleral outflow

Question 3

Use of Apraclonidine

Answer 3

• prevention + treatment postsurgical IOP elevations

Question 4

What is not longer used for prevention + treatment POAG due to tachyphylaxis + high rate blepharoconjunctivitis ?

Answer 4

• Apraclonidine

Question 5

Peak IOP of Brimonidine

Answer 5

• similar to timolol but trouhg lowering effect is less than timolol

Question 6

What effect can Brimonidine exhibit to delay visual field progression compared with timolol?

Answer 6

• exhibit neuroprotective effect

Question 7

How is brimonidine typically used?

Answer 7

• adjunctive agent in combo

- adm q8hrs

Question 8

What dosing schedule is employed when in combination therapy with Brimonidine ?

Answer 8

• 12-hr dosing

Question 9

Types of Brimonidine

Answer 9

• Brimonidine-purite 0.1% + 0.15% - Alphagan Purite similar efficiacy compared brimonidine 0.2% soln
  purite higher pH allows - more drug to penetrate cornea

Question 10

Adverse effects of brimonidine

Answer 10

Local effects:

1. blepharoconjunctivitis
2. conjunctivitis
3. ocular allergy

Systemic side effects:

1. headache
2. dry mouth
3. fatigue

Question 11

What should the patients be counselled on ?

Answer 11

• frequency dosing + local adverse effect = nonadherence

- nasolacrimal occlusion technique reduce systemic adverse effects to imrpove efficacy