Flashcards in Ocular Pharmacology Deck (24):
Systemic distribution of ophthalmically administered medications primarily occurs through _______________.
Why is there a higher potential for side effects with ophthalmically administered agents?
Because they get absorbed through the nasal mucosa and avoid first-pass metabolism
Trace the three ways by which medications can get into the systemic circulation.
Tears -> nasolacrimal drainage -> system
Tears -> cornea -> aqueous humor -> iris -> system
Tears -> sclera -> - ciliary body -> system
What is normal and glaucomatous intraocular pressure?
Normal: 10 - 15 mmHg
Glaucoma: greater than 22 mmHg
Describe drainage through the canal of Schlemm.
The canal of Schlemm is a network of drainage canals through the epithelium around the margin of the eye
What is the basic guideline for treating open-angle glaucoma?
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.
Side effects of latanoprost include _____________.
brown pigmentation of the iris and lengthening of the eyelashes
What two alpha-2 agonists are used to treat open-angle glaucoma?
Brimonidine (the BRIM of the hat) and apraclonidine
Most glaucoma is __________ angle.
Describe the treatment of closed-angle glaucoma.
Pilocarpine drops (rapid constriction of the pupil)
Acetazolamide (for decreased production of aqueous humor)
Empirical treatment of bacterial conjunctivitis is usually _____________.
erythromycin or polymixin-trimethoprim drops
Glutamate stimulates which pathway, direct or indirect?
List the colors of eye drops and what they mean.
Turquoise: prostaglandin analogues
Yellow and blue (low dose): beta-blockers
Orange: carbonic anhydrase inhibitors
Green: cholinergic agonists
What is good advice for eyedrop administration?
Place only one drop; anymore will just increase adverse effects, not the desired effect.
Hold your finger over the nasolacrimal duct to decrease runoff.
Why is acetazolamide given to those with glaucoma?
Because bicarb is needed for aqueous humor production
Bacterial keratitis is _______________.
The lacrimal gland is in which part of the eye/orbit?
The lacrimal ducts are on the ______________.
upper eyelid (throughout)
True or false: prodrugs cannot be given ophthalmically.
False. There are esterases in the local environment of the eye that can metabolize drugs such as latanoprost to their active forms.
The origin of glaucoma is not well understood, but it is known that ___________ can decrease glaucomatous damage of the optic nerve.
How do muscarinic agonists work to decrease IOP?
They stimulate the pupillary constrictor to contract and thus open the trabecular network.
In what cases would you administer fluoroquinolones of aminoglycosides ophthalmically?
Severe bacterial keratitis
Acyclovir and trifluridine can be used to treat ___________.