Pharmacology of Drugs Used For Glaucoma

Question 1

What drugs may be administered systemically to treat acute glaucoma?

Answer 1

CA inhibitors - Acetazolamide, Methazolamide (note suffix -zolamide)

Question 2

What is the first-line drug for treatment of acute, closed-angle glaucoma?

Answer 2

Acetazolamide (CA inhibitor). If pressure remains high after one hour, an osmotic agent may be administered

Question 3

What is the MOA of muscarinic agonists to treat glaucoma?

Answer 3

Increase outflow via the conventional/trabecular pathway by contracting the ciliary muscles to induce miosis (pupil constriction)

Question 4

What carbonic anhydrase inhibitors are topically given to treat glaucoma?

Answer 4

Dorzolamide, Brinzolamine (note suffix -zolamide)

Question 5

Why is apraclonidine only used for acute treatment?

Answer 5

Patients develop tachyphylaxis. This is similar to drug tolerance, but occurs more quickly. Patients between unresponsive to therapy.

Question 6

What parasympathomimetic drugs may be used to treat glaucoma?

Answer 6

Pilocarpine, Carbachol

Question 7

What are the osmotic agents used to treat glaucoma?

Answer 7

Mannitol, Glycerin, Isosorbide, Urea

Question 8

What are the clinical indications for osmotic agents in treating glaucoma?

Answer 8

Acute, closed-angle glaucoma and malignant glaucoma

Question 9

Through what two methods can aqueous humor flow out of the eye?

Answer 9

Conventional and unconventional pathways.

Question 10

Describe the inflow of aqueous humor.

Answer 10

Produced by ciliary processes in the posterior chamber, flows around the lens and pupil into the anterior chamber

Question 11

What ADRs are associated with pilocarpine and carbachol?

Answer 11

These are muscarinic agonists associated with ocular irritation, dimness of vision, myopia (nearsightedness), headache, retinal detachment

Question 12

Through what processes can glaucoma treatment be targeted?

Answer 12

Decrease inflow or increase outflow through the conventional/unconventional pathways

Question 13

True/False. Beta-blockers have no known ADRs when used for glaucoma treatment.

Answer 13

False. Beta-blockers have no local ADRs, but may cause depression, confusion, dry mouth, impotence, and fatigue.

Question 14

What classes of drugs may be used to reduce aqueous humor inflow?

Answer 14

Beta-blockers, alpha agonists, carbonic anhydrase inhibitors

Question 15

What is the only class of drugs that may be administered systemically to treat glaucoma?

Answer 15

Carbonic Anhydrase Inhibitors

Question 16

In this outflow pathway, aqueous humor is reabsorbed by ciliary muscles.

Answer 16

Unconventional (Uveoscleral) Pathway

Question 17

What are the contraindications for the use of beta-blockers in treating patients with glaucoma?

Answer 17

Asthma, COPD, bradycardia, heart failure. Blocking B2 receptors will cause bronchoconstriction and decreased HR

Question 18

Metallic taste, paresthesias, hypokalemia, and metabolic acidosis are associated with what drug class used to treat glaucoma?

Answer 18

Carbonic Anhydrase Inhibitors

Question 19

How does open-angle glaucoma differ from closed-angle?

Answer 19

Open-angle glaucoma is a chronic process due to issues with aqueous humor outflow. In open-angle glaucoma, the Iridocorneal angle is normal.

Question 20

What alpha2 agonists are used to treat glaucoma?

Answer 20

Apraclonidine, Brimonidine. Note the suffix -nidine

Question 21

What is the MOA of osmotic agents in treating glaucoma?

Answer 21

Make plasma hypertonic to draw water from vitreous humor, decrease aqueous humor production, and decrease intraocular pressure

Question 22

What are the contraindications for Brimonidine?

Answer 22

Children under 2yo due to CNS depression

Question 23

Where is aqueous humor produced?

Answer 23

By epithelium of ciliary processes in the eye

Question 24

True/False. Carbachol is more effective than pilocarpine in treating glaucome.

Answer 24

False. Pilocarpine is more effective than Carbachol, but neither are first-line agents.

Question 25

These drugs are first-line for treatment of glaucoma, with minimal systemic side effects.

Answer 25

Prostaglandin analogs

Question 26

Bimatoprost, latanoprost, tafluprost are all what type of drug?

Answer 26

Prostaglandin analogs - all have the work “prost” in the name

Question 27

Allergic reactions, blurry vision, bradycardia, decreased BP, and insomnia are ADRs associated with what medications used to treat glaucoma?

Answer 27

Alpha2 agonists - Apraclonidine, Brimonidine

Question 28

Describe the conventional pathway of aqueous humor outflow.

Answer 28

Into the trabecular meshwork, through Schlemm’s canal, and into the venous system

Question 29

What is the MOA of prostaglandins to treat glaucoma?

Answer 29

Increase outflow via the nonconventional/uveosclearal pathway

Question 30

What ADRs are associated with prostaglandin analogs?

Answer 30

Conjunctival hyperemia, hyperpigmentation of skin, eyelash growth, darkening of the iris

Question 31

True/False. Closed-angle glaucoma is an acute process that is considered a medical emergency.

Answer 31

True. Close-angle glaucoma results from pupillary or non-pupillary block.

Question 32

This Beta Blocker is the most ineffective in treating glaucoma due to its selectivity for B1 receptors.

Answer 32

Betaxolol

Question 33

What symptoms characterize glaucoma?

Answer 33

Retina ganglion cell death, vision problems and blindness, increased cup/disc ratio, increased intraocular pressure (not always)