20 - Anti - glaucoma drugs

Question 1

what are topical classes of drugs for glaucoma

Answer 1

• prostaglandin agonists
• beta receptor antagonists
• alpha 2 receptor agonists
• carbonic anhydrase inhibtors
• cholinergic agonists

Question 2

what is the mechanism of action for these topical drugs

Answer 2

• lowering IOP (ocular hypertensive meds)

1. reduce aqueous production (CAI, a2ra, beta r.a - work on ciliary epithelium)
2. increase outflow through trabecular meshwork (cholinergics)
3. increase uveoscleral flow (PGA, prostamide, brimonidine)

Question 3

systemic classes of glaucoma drugs (Acute angle closure)

Answer 3

• carbonic anhydrase inhibiroes (acetazolamide) - single dose/tablet
• osmotic agents (glycerol/mannitol)

Question 4

before prescribing any new eye drop for glaucoma?

Answer 4

• general medical history
• drug history
• history of topical allergy
• find out if px can use drops ; memory/dexterity/carers

Question 5

latonoprost vs timolol

Answer 5

latonoprost but not by much

Question 6

where do PGA act

Answer 6

uveo scleral pathway

Question 7

name some prostoglandin anologs

Answer 7

• latanoprost
• travuprost
  -tafluprost

Question 8

side effects of PGA

Answer 8

• conjunctival hyperaemia , more pronounced in early stages of treatment
• darkening/thickening of lashes
• increased iris pigmentation

Question 9

name some Beta- antagonists

Answer 9

• timolol
  -betaxolol
• levobunolol Hcl

Question 10

what type of beta blocker is betaxolol

Answer 10

selective

Question 11

what type of beta blocker is timolol

Answer 11

non selective

Question 12

what are side effecs of beta antagonists

Answer 12

• bronchpconstriction: esp in px with obstructive airways disease or asthma

Question 13

If prescribing B antagonists

Answer 13

• ask about COAD inhalers
• check pulse
• check peak flow
• considering drug interactions
• recheck peak flow 1 month after starting treatment, stop if fall of 15%

Question 14

name some alpha agonists

Answer 14

• Brimonidine tartrate
• Apraclonidine

Question 15

when is Apraclonidine used and why

Answer 15

pre and post operative setting, as an effective short term IOP lowering agent

Question 16

how does brimonidine work

Answer 16

• reducing aqueous secretion as well as increasing uveoscleral outflow

Question 17

side effects of alpha agonists

Answer 17

a2 receptor agonists

ocular
- follicular conjunctivitis

systemic
- hypotension
- syncope
- dry mouth/nose
- headache
- anxiety
- depression
- fatigue

Question 18

carbonic anhydrase inhibitors - likely to be used when?

Answer 18

fixed combination with beta blockers as less efficous

Question 19

name some carbonic anhydrase inhibitors

Answer 19

• dorzolamide hcl
• brinzolamide hcl

Question 20

topical side effects of CAI

Answer 20

• metallic taste
• rashes
• irritation
• blurred vision

Question 21

side effects of oral CAI

Answer 21

• allergy
• hypokalemia
  -polyuria
• acidosis
• depression
• kidney stones
• paresthesia
• blood dyscrasia

Question 22

cholinergic agonists

Answer 22

rarely prescriped - expensive

• pilocarpine hcl
• pilocarpine nitrate

Question 23

side effects of cholinergic agonists

Answer 23

• miosis
• myopia
• Symblepharon
• retinal detatchment
• confusion
• vomiting
• nausea

Question 24

more than drops?

Answer 24

• surgery
• laser