Flashcards in Pharmacology Deck (43):
Corneal penetration is good for what type of drugs?
Low molecular weight
Is the epithelium of the cornea lipophilic or hydrophilic?
Is the stroma of the cornea lipophilic or hydrophilic?
Give an example of a drug that has both lipophilic and hydrophilic, and so easily penetrates the cornea?
If there is ocular surface inflammation, how does this affect the cornea?
Reduces the lipophilic nature of the endothelium (ie Makes it more hydrophilic)
What part of tears may impede drug penetration?
Do topical steroids need to be hydrophobic, hydrophilic or both?
What chemicals can modify topical steroids to make them:
A) More hydrophobic
B) More hydrophilic
In what corneal state would prednisolone acetate be used?
When is prednisolone acetate used?
In what corneal state would prednisolone phosphate be used?
When is prednisolone phosphate used?
If low does steroids are needed
What is benzalkonium and how does it work?
Disrupts lipid layer of tear film:
- Aids penetration of some drugs
What drugs is used to treat increased IOP in glaucoma and what is the benzalkonium concentration?
- [Benzalkonium) = 0.05mg/ml
What is the benzalkonium concentration in Bimatoprost 0.01%?
How can topical drugs reach the systemic circulation? What can limit this?
Tears pumped out of lacrimal gland rapidly:
- Excess is absorbed in nasopharynx
When are topical steroids used?
Prevent corneal graft rejection
Which of the following is not a systemic side effect of steroids:
- Gastric ulceration
- Weight loss
- Neuropsychiatric effects
Weight loss (causes weight gain)
What local effects can topical steroids have on the eye?
Exacerbation of viral symptoms (Corneal melt in herpetic ulcer)
Rank the following topical steroids from weakest to most potent:
When are antihistamines and mast cell stabilisers used?
When would topical NSAIDs be used?
Post-refractive laser treatment
What is the only modifiable risk factor for glaucoma?
What speed of progression does glaucoma typically have?
When treating glaucoma, is the goal to halt it or slow progression?
Give an example of a prostanoid used to treat glaucoma
Give an example of a beta blocker used to treat glaucoma
Give an examples of some carbonic anhydrase inhibitors used to treat glaucoma
Topical -> Dorzolamide
Systemic -> Acetazolamide
What classes of drugs are Brimonidine and Pilocarpine and what are they used to treat?
Brimonidine -> Alpha2 adrenergic agonist
What is cosopt?
Combination of Dorzolamide and Timolol
What drugs are administered intravitreally and what are they used to treat?
Antibiotics -> Endophthalmus
Anti-VEGF -> Proliferative retinopathy
How do ophthalmic anaesthetics work?
Block Na+ channels and impede nerve conduction
In which of the following situations would ophthalmic anaesthetics not be used:
- Foreign body removal
- Tonometry (IOP measurement)
- Corneal scraping
When is fluorescein used?
In corneal abrasion
Nasolacrimal duct obstruction
Apart fro fluorescein, what is another diagnostic dye?
How do mydriatics work?
Block parasympathetic supply to iris -> Pupil dilation
Give some examples of mydriatics
What are some side effects of mydriatics?
Acute angle-closure glaucoma
What do sympathomimetics do to the pupil? What do they not affect?
Don't affect ciliary muscles -> Allow accommodation
Give some examples of sympathomimetics
What is a side effect of vigabratin (anti-epileptic)?
Constricts visual field
What is an optical side effect of ethambutol?