L42 Drugs for ophthalmic (eye) disorder→↑↓

Question 1

Treatment of bacterial and viral

conjunctivitis

Answer 1

Antibacterial agents
→ Ofloxacin
→ Tobramycin
→ Gentamicin
→ Chloramphenicol

Antiviral agents
→ Acyclovir

Question 2

Treatment of allergic

conjunctivitis

Answer 2

Antihistamine (reduce itchiness
and watery eyes by blocking the
action of inflammatory mediator
histamine)
→ Chlorpheniramine

Decongestant (reduce redness of
eye by constricting blood
vessels)
→Naphazoline

Mast cell stabilizers (reduce
itchiness and watery eyes by
preventing the inflammatory
mediators released from Mast
cells)
→ Cromolyn sodium

Corticosteroid (reduce
inflammation by
suppressing the immune
response)
→ Prednisolone
→ Concern for development of
cataract
→ Increase chance of infection
→ Risk of steroid-induced
glaucoma

Non-steroidal anti-inflammatory
drugs (NSAIDs)
→Flubiprofen
→Ketorolac
→Diclofenic
→Bromofenac
→Nepafenac

Question 3

Treatment of Other eye infections

Answer 3

Keratitis
Treatment: antibacterial and
antiviral agents (same as those
for conjunctivitis)

Blepharitis and stye 
inflammation of the eyelid • It is typically caused by bacterial infection or
blockage of the meibomian
oil glands
• Most cases of styes resolve
on their own

 Treatment: 
→Warm compress 
→Antibacterial agents (same as those for conjunctivitis)
→ Use eye ointment rather
than eyedrop

Question 4

Dry eye

Answer 4

Artificial tear

Question 5

Treatment of Glaucoma

Answer 5

β blockers
→ Examples: timolol, betaxolol
MoA
→ Epithelium of ciliary body-responsible for production of aqueous humor- controlled by β receptors (mostly β2 receptors)
→Blockade of β receptors →↓
aqueous humor → ↓ ocular pressure

α2 receptor agonists
→Examples: Apraclonidine, brimonidine
stimulation of α2 receptors in epithelium of ciliary body → ↓ aqueous humor → ↓ ocular pressure

Carbonic anhydrase inhibitors
acetazolamide (oral), dorzolamide
Inhibition of carbonic anhydrase in epithelium of ciliary body 
→ ↓  formation of bicarbonate ion 
→ →↓  bicarbonate and sodium secretion 
→→→ ↓  fluid secretion
→→→→ ↓  ocular pressure

Prostaglandins
 (latanoprost, bimatoprost)
PGF2α analogs
→Facilitate aqueous
outflow
→increase uveoscleral outflow of aqueous humor, probably by increasing permeability of tissues in ciliary muscle

Muscarinic receptor agonists Pilocarpine
Not degraded by cholinesterase
 Contract ciliary muscle in
eye → improve draining
(trabecular outflow) → ↓ ocular pressure
 Also constrict pupil and
blur vision (side effect)

Cholinesterase inhibitors
• Example: physostigmine
• Lipid soluble
• ↓ breakdown of acetylcholine → ↑ level of acetylcholine
→ ↑stimulation of muscarinic receptors in ciliary muscle
→ improve draining (trabecular outflow) → ↓ ocular pressure

Also constrict pupil and blur vision (side effect)