Pharmacology Flashcards
(50 cards)
Why does the topical route of admission pose difficulties?
The drug has to both be lipophilic and hydrophilic in order to pass through the aqueous components and the lipid bound epithelium.
Give an example of both a lipophilic and hydrophobic drug?
Chloramphenicol
Why does an inflamed eye improve the uptake of drugs?
Inflammation creates gaps between the epithelial cells allowing less lipophilic drugs a site of entry.
Why do ointments have a higher uptake of the drug through the eye than drops?
Ointments are not washed or blinked away as easily so stay for longer on the surface of the eye.
In regards to steroids what can be added to make them more hydrophilic?
Phosphate groups
In regards to steroids what can be added to make them more lipophilic?
Acetate groups
Give an example of a hydrophobic steroid.
Prednisolone Acetate
When is prednisolone acetate used and why?
Used post operatively
Good penetration of the eye
Give an example of a hydrophilic steroid and explain how this impacts its usage.
Prednisolone Phosphate
Doesn’t penetrate the eye so used for surface level inflammation
What drug increases the uptake of other drugs through the eye?
Benzalkonium
How does benzalkonium work?
It disrupts the lipid bilayer allowing the drug entry.
How can topical applications be systemically absorbed?
The lacrimal duct empties into the nasopharynx.
How can systemic absorption be limited in topical applications?
Pinch the bridge of the nose to obstruct the lacrimal duct for a period of time after application.
When treating infections of the posterior eye why can drugs not be administered systemically?
The Blood retinal barrier prevents the drugs from entering the optic environment.
How are drugs administered to the posterior chamber?
Intravitreal injection
How are drugs administered into the front of the eye?
Intracameral injection
What anti inflammatories are commonly used for the eye?
Steroids
NSAIDs
Antihistamines
Mast Cell stabilisers
When are steroids used?
Post Operative Cataracts
Uvietis
Prevention of corneal graft rejection
When are IV steroids used in a clinical setting?
Suspicion of temporal arteritis
What are some local effects of steroid use?
Cataracts
Glaucoma
Exacerbation of viral infection - corneal melt
What are some systemic effects of steroid use?
Gastric ulcers
Osteoporosis
Weight gain
List some of the commonly used steroid in order from least to most potent.
FML
Prednisilone - Phosphate
Beclamethasone
Dexamethasone - Acetatae
Glaucoma can be completely stopped. T/F
False
We are only able to slow the progression of the disease.
List the types of drugs available for the treatment of a glaucoma.
Prostanoids Beta Blockers Carbonic Anhydrase inhibitors Alpha Adrenergic Agonist Parasympathimimetics
