Pharmacology: Routes of Administration Flashcards
Prednisolone acetate is hydro______
Hydrophobic
Drugs applied ________ to the eye are given as drops or ointment
Topically
Which form of prednisolone (phosphate or acetate) has good penetration in an uninflamed cornea?
Prednisolone acetate
Which layer of the tear film may impede drug penetration?
Lipid layer
The outer corneal layer is mostly made up of epithelial cells - highly lipophilic so acts as a barrier for _________ drugs
Hydrophilic
How can you prevent a patient getting a nasty taste at the back of their throat after using eye drops?
Punctal occlusion (holding tear duct shut)
When would prednisolone acetate be indicated?
Post-operatively
Describe the subtendon route of drug administration
Injection between the sclera and the Tenon capsule
Describe the subconjunctival route of drug administration
Injection under the conjunctiva, which allows drugs to bypass the corneal epithelium
Describe the intravitreal route of drug administration
Injection into the viteous cavity
Why do topical steroids need to be chemically modified?
Modifications alter characteristics to make the steroid hydrophilic or hydrophobic depending on the requirement
Why can’t intravitreal injections be used for all drugs?
Many drugs are toxic to the retina
Eye drop bottles have preservative in them which keeps bottle free from contaminants for __ weeks
4
When would prednisolone phosphate be indicated?
Used for corneal disease or when low dose steroids required
Name a chemical used to enhance corneal permeability to topical drugs and therefore increase active drug bioavailability
Benzalkonium chloride
