IOP lowering drugs Flashcards
Name the different classes of IOP lowering drugs and give examples of each
Beta blockers e.g., timolol
Prostaglandin analogues e.g., latanoprost
Alpha-2 agonists e.g., apraclonidine
Topical carbonic anhydrase inhibitors (CAI) e.g., acetazolamide
Systemic CAI e.g., acetazolamide
Miotics e.g., pilocarpine
Osmotic agents e.g., mannitol
What is the mechanism of action of beta-blockers?
B2 receptors found on ciliary processes and trabecular meshwork
Exact MOC is unknown:
- increased aqueous outflow
- decreased aqueous production
What is the mechanism of action of CAIs (systemic and topical)?
Inhibit carbonic anhydrase which is found in the ciliary body epithelium
CA is key enzyme in aqueous production
What is the mechanism of action of prostaglandin analogues?
Increased aqueous drainage via the uveoscleral outflow
What is the mechanism of action of alpha-2 agonists?
Decreased aqueous production and increased uveoscleral outflow
What is the mechanism of action of mitotics?
Parasympthomimetics
Increase aqueous drainage via trabecular network by causing contraction of ciliary muscles
What is the mechanism of action of osmotic agents?
Lowers IOP by decreasing vitreous volume
What are the side effects of beta-blockers?
Decreased corneal sensation
Dry eyes
Tachyphylaxis
Bradycardia
Bronchospasm
Nocturnal hypotension
What are the side effects of prostaglandin analogues?
Conjunctival hyperaemia
Iris hyperpigmentation
Increased eyelash length
Cystoid macular oedema (CMO)
What are the side effects of alpha-2 agonists?
Follicular conjunctivitis
Contact dermatitis
Tachyphylaxis
Dry mouth
Sedation
In which group of people should you use alpha-2 agonists with caution?
Infants
Can cross BBB
What are the side effects of topical CAIs?
Ocular stinging
Bitter taste
Punctate keratitis
In which group of people are topical CAIs contraindicated?
Sulphonamide allergies
What are the side effects of systemic CAIs?
Paraesthesia
Urine frequency (diuretic effect)
Hypokalaemia
SJS
Metabolic acidosis
What are the side effects of mitotics?
Myopia
Brow ache
Miosis
Retinal detachment
What are the side effects of osmotic agents?
Cardiovascular overload
