Lecture 10 - Prostaglandin Analogs Flashcards
True or False. Dose is not crucial when using prostaglandins, as it no disruption of he blood aqueous barrier?
False. Dose is crucial and it does disrupt the blood aqueous barrier
True or False. High dose topically will raise IOP?
True.
Note: Intracamerally it will also increase
True or False. Prostaglandins are the most effective and commonly used for lowering IOP?
True
What are Prostaglandin analogs a prodrug of?
Prostaglandin F2a
What converts PG’s into its active form when placed on the cornea?
Corneal enzymes
When PG’s are administered they activate the PGF2a receptor, but where are these receptors located?
CB
What are the three ester based PG prodrugs?
Latanoprost, Travoprost and unoprostone
Bimatoprost is described as what type of amide group?
prostamide
Note: An amide group will have a Nitrogen attached to the carbonyl group of its organic structure
What is the primary goal of a PG?
Increase outflow through uveoscleral pathway
Note: There is a small % increase in coventional outflow
True or False. PG’s reduce aqueous production.
False. It only works on outflow.
Note: The mechanism of action is not fully understood
According to the relaxation of CB muscle theory, what happens to the CB when using latanprost?
CB INCREASES in thickness
What is the proposition of Dilated spaces between ciliary muscle bundles theory?
PG induced stimulation of collagenase and other matrix metalloprotenases
What the indications of using PG’s?
Primary open angle glaucoma (POAG), Normal tension glaucoma (NTG), Pigment dispersion syndrome (PDS), Exfoliation syndrome (XF) and Chronic angle closure glaucoma Caution with uveitic glaucoma and Less effective in pediatric glaucoma
What are the 4 contraindications of PG?
- Allergies to the PG
- Pregnancy
- Peds
- Unclear PG’s and Ocular inflammation
What type of macular inflammatory reaction is Latanoprost associated with?
Cystoid Macular Edema (CME)
Note: Largest contraindication with PG’s
What three type of ocular issues should PG’s not be used with?
- CME
- Iritis
- Herpes Simplex Keratitis
When should you take a PG and why are you only taking it once a day?
Take in the evening and you only take it once, as two would be less effective
What are the 5 side effects of PG’s?
- Conjunctival hyperemia
- Iris color change
- Eyelash changes
- Skin pigmentation
- Deepening of upper eye lid sulcus (DUES)
Which PG causes conjunctival hyperemia the most?
Brimatoprost
Whats a well documented side effect of PG’s?
Iris color change
What cosmetic product ingredient and PG causes an increase in eyelashes
Bimatoprost
True or False. Topical PG’s don’t affect retinal vasculature
True
How long in advance should you stop taking PG”s, prior to cataract surgery
1 month
Note: You can start taking it again after 1 month
What is the half life of PG’s in human plasma?
17 minutes
Note: There is no effect on blood pressure
What perservative mixed with latanoprost will form a precipitate?
Thimerasol
Which has a larger effect on IOP, Timolol or Latanoprost?
Latanoprost
Timolol will lower by 6.3 mmHg
Latanoprost will lower by 7.6 mmHg
Note: When put together they work even better (24% to 37% decline)
What has better effects on African Americans, Timolol or PG’s?
PG’s
True or False. Adding adrnergic agonists like brimonidine to latanoprost produces similar effect like adding dorzolamide
True
What do cholinergic agonists do to trabecular outflow and what anatomical structures are impacted?
Increase outflow
- Contraction of Ciliary muscle
- Pulls on scleral spur
- Opens channels in TM
Note: Uveoscleral outflow decreases, but that doesn’t mean you stop using PG’s
What are 3 benefits of fixed combination drugs?
- More convenient
- Less expensive
- Improved compliance
Why is timolol not part of combination drugs?
It does not produce a decrease in IOP of 20%
What new drug does not produce any heart/lung issues but lowers IOP?
Unoprostone RESCULA
