Term
How does Cimetidine inhibit the metabolism of other drugs? |
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Definition
Cimetidine interferes with the cytochrome P-450 system |
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Term
Name three drugs that stimulate the hepatic metabolism of other drugs. |
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Definition
1. Phenobarbital 2. Oral contraceptives 3. Low doses of alcohol |
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Term
What is the most common method of administering ocular drugs? |
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Definition
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Term
What are five types of topcial administration? |
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Definition
1. Drops 2. Sterile Opthalmic solution 3. Suspensions ((steroids) 4. Gels, e.g. artificial tears given at night 5. Ointment (UNG)-Bacitracin is a popular antibiotic ointment for blepharitis |
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Term
What are three types of intraocular injections? |
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Definition
1. Subconjunctival injections 2. Subtenon injections 3. Intravitreal injections |
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Term
How many drops are in a ml? |
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Definition
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Term
What is the normal tear layer volume? |
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Definition
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Term
What is the maximum volume the eye can hold? |
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Definition
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Term
What is the normal drop size? |
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Definition
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Term
Can drugs pass through the cornea by simple diffusion? |
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Definition
No the cornea functions as a trilaminar permeability barrier. |
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Term
How does a drug get through the cornea? |
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Definition
The drug must have hydropbobic properties to get through the epithelium and endothelium, but the drug must also have hydrophilic properties to get through the hydrophilic stroma. |
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Term
Give one example of a drug administered as a gel. |
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Definition
Timoptic/timolol-a beta blocker for glaucoma |
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Term
What are three disadvantages of ointments? |
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Definition
1. blurred vision 2. must instill drops before instilling the ointment 3. Imprecise instillation |
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Term
Give an example of a drug used as an emulsion. |
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Definition
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Term
What are two advantages to drugs being administered as emulsions. |
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Definition
1. decreased toxicity 2. increase in therapeutic window time |
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Term
When would you give an intravenous injection for an eye disease? |
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Definition
1. If the infection gets into the orbit or into the sinuses.
e.g. orbital cellulitis or preseptal cellulitis |
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Term
What are three advantages of solutions and suspensions? |
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Definition
1. Ease of instillation 2. Alterations in visual acuity less noticeable 3. Fewer complications |
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Term
What are four disadvantages of using solutions and suspensions? |
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Definition
1. Suspensions must be resuspended each time they are used. 2. Imprecise dosing 3. May be minimized by refrigeration. 4. Trauma from applicator tip 5. Contamination of tip (from eyelashes and conjunctiva touching the tip) |
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Term
Name three major prostaglandin glaucoma meds. |
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Definition
Travatan, xalatan, lumigan |
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Term
Name an antibiotic without preservative. |
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Definition
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Term
Why do depression drugs have a huge volume of distribution? |
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Definition
They must act on the brain. Therefore they must be lipid soluble. Lipid soluble drugs have a huge volume of distribution. |
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Term
What is the sole determinant of the rate that a drug approaches steady state? |
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Definition
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Term
What is the loading dose in practice? |
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Definition
Double the first and second dose then take a normal dosage. |
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Term
What is the standard dose frequency for steroids? |
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Definition
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Term
How often do you administer a topical drug for uveitis? |
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Definition
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Term
How often do you administer drops for a corneal ulcer? |
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Definition
2 drops in the first five minutes and then 1 drop every ten minutes until steady state is acheived. |
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Term
What is the maximal response a drug can give? |
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Definition
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Term
What is the amount of drug that leads to 50% efficacy? |
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Definition
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