Glaucoma Drugs (Konorev) Flashcards
What are the two muscles that make up the iris and what is there function?
iris “circular” muscle or sphincter pupillae - constricts pupil (miosis)
iris “radial” muscle or dilator pupillae - dilates pupil (mydriasis)
receptor for iris “circular” muscle or sphincter pupillae
M3 - Gq pathway; remember if you’re constricting the pupil it is a parasympathetic action
receptor for iris “radial” muscle or dilator pupillae
alpha 2 - Gq pathway; remember if you’re dilating the pupil it is a sympathetic action
Normal physiology of aqueous humor production
produced by the ciliary epithelium; Beta receptors stimulate its production (Gs); alpha 2 receptors inhibit its production (Gi); carbonic anhydrase enzyme increases it production
What are the 3 classes drugs that inhibit aqueous humor production?
- beta blockers - Timolol (favored), Betaxolol, Timolol, Carteolol, Metipranolol, Levobunolol
- alpha 2 agonist - Apraclonidine and Brimonidine
- CA inhibitors:
topicals - Brinzolamide and Dorzolamide
systemics - Acetazolamide and Methazolamide
What are the 5 beta blockers used to decrease aqueous humor production in glaucoma?
Timolol (favored), Betaxolol, Carteolol, Metipranolol, Levobunolol
Which beta blocker is favored for the use of glaucoma and why?
Tamolol; lacks local anesthetic effects (more favorable for glaucoma patients); available as a generic and is a full antagonist
Adverse effects of beta blockers?
systemic parasympathetic effects; local effects - ocular irritation and dry eyes
What are the two alpha 2 receptor agonist that is used to decrease aqueous humor production in glaucoma?
Brimonidine and Apraclonidine (less used due to allergies)
Adverse effects of alpha 2 receptor agonist?
Headaches, fatigue and dry mouth; local - allergic reactions
What are the two classes of carbonic anhydrase inhibitors used to treat glaucoma?
“zolamide’s”
topicals - Brinzolamide and Dorzolamide
systemics - Acetazolamide and Methazolamide
Brinzolamide and Dorzolamide
topical carbonic anhydrase inhibitors used to treat glaucoma
Acetazolamide and Methazolamide
systemic carbonic anhydrase inhibitors used to treat glaucoma
What are the adverse effects of carbonic anhydrase inhibitors?
Nausea, diarrhea, loss of appetites, altered taste
Weight loss, paresthesias, renal stones and decreased libido
Which prostaglandin analog is most effective in lowering intraocular pressure (IOP)?
Bimatroprost
What are the 3 classes of drugs that is used to glaucoma by increasing aqueous humor outflow?
- Cholinergic agonist (direct) - Pilocarpine and Carbachol
- Cholinesterase inhibitor (indirect cholinergic agonist) - Echothiophate
- Prostaglandin F2alpha analogs - Bimatoprost (favored), Latanoprost and Travoprost
MOA of cholinergic agonist in treating glaucoma?
activate the M3 receptor (Gq) on the ciliary muscles; increases the outflow of aqueous humor
MOA of cholinesterase inhibitor in treating glaucoma?
inhibits acetylchlinesterae inhibitor; allowing more acetylcholine to be available for activation of the M3 receptor on the ciliary muscle to increase the outflow of aqueous humor
Adverse effects of the cholinergic agonist (both direct and indirect)?
headaches and periorbital pain, miosis, eyelid twitching, myopia, cataracts, and iris-lens adhesions
Pilocarpine and Carbachol
Cholinergic agonist (direct) agents used to treat glaucoma by activating the M3 receptor (Gq) on the ciliary muscles; increases the outflow of aqueous humor
Echothiophate
Cholinesterase inhibitor (indirect cholinergic agonist) used to treat glaucoma by inhibiting acetylchlinesterae inhibitor; allowing more acetylcholine to be available for activation of the M3 receptor on the ciliary muscle to increase the outflow of aqueous humor
What are the first line treatment for open angle glaucoma?
beta blockers - Timolol (favored), Betaxolol, Timolol, Carteolol, Metipranolol, Levobunolol
OR
Prastaglandin F2alpha analogs - Bimatoprost (favored), Latanoprost and Travoprost
What are the 3 prostaglandin analogs and what is their MOA?
Bimatoprost (favored), Latanoprost and Travoprost; increase aqueous humor outflow
Adverse effects of prostaglandin analogs?
Corneal erosions, conjunctival hyperemia, iris hyperpigmentation (irreversible), hypertrichosis (hyperpigmentation around eyelashes and eyelids)
Which class of drug can cause hypertrichosis?
prostaglandin analogs; Bimatoprost (favored), Latanoprost and Travoprost; hyperpigmentation around eyelashes and eyelids
What are the two types of closed angle glaucoma (CAG)?
With pupillary block - tight contact between iris and the lens; blocks flow of aqueous humor into anterior chamber
Without pupillary block - ciliary processes are located in a way that they push the iris forward and block outflow
Treatment of closed angle glaucoma (CAG)?
- decreased IOP - Give systemic diuretics - Oral Glycerin or IV Mannitol
- induce miosis - Pilocarpine
- Reduce aqueous humor - beta blockers, alpha 2 agonist or CA inhibitors
- Surgery or laser iridectomy
