Ocular Pharmacology and Therapeutics Flashcards

Which systemic condition is a contraindication to topical timolol?

Answer: Bronchial asthma

Nonselective beta-blockers like timolol can cause bronchospasm through beta-2 blockade, so they are contraindicated in asthma.

Brimonidine is contraindicated in infants and children under 2 years mainly because of which risk?

Answer: CNS depression and apnea

Brimonidine readily crosses the blood-brain barrier in infants, which can cause somnolence, hypotonia, bradycardia, and apnea.

Long-term oral acetazolamide therapy is most closely associated with which adverse effect?

Answer: Calcium phosphate nephrolithiasis

Carbonic anhydrase inhibition causes metabolic acidosis, reduced urinary citrate, and alkaline urine, which favor calcium phosphate stones.

What is the main mechanism by which latanoprost lowers intraocular pressure?

Answer: It increases uveoscleral outflow

Prostaglandin F2-alpha analogs remodel the ciliary muscle extracellular matrix through matrix metalloproteinases, which increases uveoscleral outflow.

Why is pilocarpine often ineffective early in acute angle-closure with IOP above 50 mm Hg?

Answer: Pressure-induced ischemia of the iris sphincter

Very high IOP causes ischemic paralysis of the iris sphincter, so it cannot respond to miotics until pressure is lowered by other means.

Which pair of ocular side effects is characteristic of netarsudil?

Answer: Conjunctival hyperemia and corneal verticillata

The Rho kinase inhibitor netarsudil often causes conjunctival hyperemia and a whorl-like corneal verticillata that is usually benign.

Which patient faces the greatest risk from IV mannitol given for acute IOP reduction?

Answer: A patient with congestive heart failure

Mannitol expands intravascular volume and can precipitate pulmonary edema in patients with heart failure or renal failure.