Drugs used in Glaucoma Flashcards
(28 cards)
Iris ciscular muscle function and receptor
constricts pupil to cause miosis
M3 receptors
Iris radial muscle function and receptor
Dilates pupil to cause mydriasis
a1 adrenergic receptor
Ciliary muscle function and receptor
Accommodation of the eye to near vision
M3 receptors
What produces/secretes aqueous humor?
ciliary epithelium
What is the role of B adrenergic receptor activation in humor production
increases humor production
What is the role of a2 adrenergic receptor activation in humor production?
decreases humor production
What is the role of carbonic anhydrase in the regulation of intraocular pressure (IOP)
Transports sodium and bicarbonate ions from the ciliary body to the aqueous humor
Increase in osmotic pressure of the aqueous humor enhances transport of water to the humor to increase its volume
What is the role of muscarinic receptors in regulation of IOP?
conventional outflow
Contraction of ciliary muscle –> improved outflow
Contraction of iris circular muscle, miosis- improved outflow
What is the rols of the sympathetic nervous system in regulation of IOP
Contraction of iris radial muscle (a1), mydriasis - decreased outflow (conventional outflow)
Relaxation of the ciliary muscle (presynaptic a2) - increased uveoscleral outflow
What is the difference between open angle and closed angle glaucoma?
open angle is a chronic progressive disease with no blockage for humor outflow
Closed angle is intermittent partial of complete blockage that may have to be treated as an emergency to prevent vision loss
What are the drug categories that reduce aqueous humor production
B-blockers
a2 adrenergic agonists
Carbonic anhydrase inhibitors
Which B-blocker is favored in treatment?
Why?
Timolol
Lacks local anesthetic effects
available as genetic
full antagonist
What are the B-blockers used in the reduction of humor
betaxolol timolol metipranolol levobunolol carteolol
What are the a2 agonists used in reduction of humor
Brimonidine (first line)
Apraclonidine
What are the topical carbonic anhydrase inhibitors used in reduction of humor
Brinzolamide
Dorzolamide
What are the systemic carbonic anhydrase inhibitors used in reduction of humor
Acetazolamide
Methazolamide
What are the drug categories that increase the aqueous humor outflow?
Prostaglandin analogs
a2 adrenergic agonists
Direct cholinergic agonists
Cholinesterase inhibitors (indirect cholinergic agonists)
What are the prostaglandin analogs that increase outflow
latanoprost
bimatoprost - most effective at lowering IOP
travoprost
What is the MOA of the prostaglandin analogs
reduce IOP byy increaseing the uveoscleral and, to a lesser extent, conventional outflow of aqueous humor
What are some notable side effects of the prostaglandin analogs?
iris hyperpigmentation
reversible hypertrichosis and hyperpigmentation around the eye lashes and eyelids
What are the direct acting cholinergic agonists
pilocarpine
carbachol
What is the indirect acting cholinergic agonist (cholinesterase inhibitor)
echothiophate
How do you treat open angle glaucoma?
IF there are contraindications?
If intolerance or inadequate response to combination therapy?
1) start with a B-blocker or a prostaglandin agent
2) switch to brimonidine or topical carbonic anhydrase inhibitors
3) laser or surgical procedure
What is a technique used in the treatment of open angle glaucoma?
Nasolacrimal duct occlusion technique
Apply pressure for about 3 mins over the nasolacrimal sac after eye drops are applied
