Ocular Pharmacology

Question 1

Systemic distribution of ophthalmically administered medications primarily occurs through _______________.

Answer 1

nasolacrimal drainage

Question 2

Why is there a higher potential for side effects with ophthalmically administered agents?

Answer 2

Because they get absorbed through the nasal mucosa and avoid first-pass metabolism

Question 3

Trace the three ways by which medications can get into the systemic circulation.

Answer 3

Tears -> nasolacrimal drainage -> system
Tears -> cornea -> aqueous humor -> iris -> system
Tears -> sclera -> - ciliary body -> system

Question 4

What is normal and glaucomatous intraocular pressure?

Answer 4

Normal: 10 - 15 mmHg
Glaucoma: greater than 22 mmHg

Question 5

Describe drainage through the canal of Schlemm.

Answer 5

The canal of Schlemm is a network of drainage canals through the epithelium around the margin of the eye

Question 6

What is the basic guideline for treating open-angle glaucoma?

Answer 6

First line: prostaglandin analogue (latanoprost)
Second line: beta-blocker or alpha-2 agonist (cholinergic agonists less commonly used, as are carbonic anhydrase inhibitors)

Use PA. If PA decreases IOP but not enough, add a second-line. If PA doesn’t decrease IOP by a significant amount, discontinue PA and switch to second-line drug.

Question 7

Side effects of latanoprost include _____________.

Answer 7

brown pigmentation of the iris and lengthening of the eyelashes

Question 8

What two alpha-2 agonists are used to treat open-angle glaucoma?

Answer 8

Brimonidine (the BRIM of the hat) and apraclonidine

Question 9

Most glaucoma is __________ angle.

Answer 9

open

Question 10

Describe the treatment of closed-angle glaucoma.

Answer 10

Pilocarpine drops (rapid constriction of the pupil)
Acetazolamide (for decreased production of aqueous humor)
Mannitol

Question 11

Empirical treatment of bacterial conjunctivitis is usually _____________.

Answer 11

erythromycin or polymixin-trimethoprim drops

Question 12

Glutamate stimulates which pathway, direct or indirect?

Answer 12

Both!

Question 13

List the colors of eye drops and what they mean.

Answer 13

Turquoise: prostaglandin analogues
Yellow and blue (low dose): beta-blockers
Purple: alpha-2
Orange: carbonic anhydrase inhibitors
Green: cholinergic agonists
Red: mydriatics
Tan: antimicrobials
Pink: anti-inflammatory
Gray: NSAIDs

Question 14

What is good advice for eyedrop administration?

Answer 14

Place only one drop; anymore will just increase adverse effects, not the desired effect.

Hold your finger over the nasolacrimal duct to decrease runoff.

Question 15

Why is acetazolamide given to those with glaucoma?

Answer 15

Because bicarb is needed for aqueous humor production

Question 16

Bacterial keratitis is _______________.

Answer 16

corneal ulcers

Question 17

The lacrimal gland is in which part of the eye/orbit?

Answer 17

Superior lateral

Question 18

The lacrimal ducts are on the ______________.

Answer 18

upper eyelid (throughout)

Question 19

True or false: prodrugs cannot be given ophthalmically.

Answer 19

False. There are esterases in the local environment of the eye that can metabolize drugs such as latanoprost to their active forms.

Question 20

The origin of glaucoma is not well understood, but it is known that ___________ can decrease glaucomatous damage of the optic nerve.

Answer 20

reducing IOP

Question 21

How do muscarinic agonists work to decrease IOP?

Answer 21

They stimulate the pupillary constrictor to contract and thus open the trabecular network.

Question 22

In what cases would you administer fluoroquinolones of aminoglycosides ophthalmically?

Answer 22

Severe bacterial keratitis

Question 23

Acyclovir and trifluridine can be used to treat ___________.

Answer 23

herpetic keratitis

Question 24

True or false: you ought to give antivirals to someone with viral conjunctivitis.

Answer 24

False! There is no treatment for viral conjunctivitis other than symptomatic relief (from decongestants).