Intro to Pharm Flashcards
When observing drug scheduling how is it set up?
Schedule 1 have the highest abuse potential.
Schedule V have the lowest abuse schedule.
Describe the 4 clinical testing phases
Phase I Safe dosing range
Phase II does it work
Phase III well controlled, more patients.
Phase IV monitor during clinical use.
What is the difference between a drugs efficacy and its potency?
Potency is how strongly the enzyme binds to the drug (Km).
The efficacy is the maximum effect the drug can induce (Emax)
How do you calculate the therapeutic index?
Mean toxic dose / Mean effective dose
Whats the difference between parenteral and enteral drug absorption?
Parenteral is through injection or intrathecal.
Enteral: Oral, sublingual, buccal, rectal.
Where are weak acids and bases absorbed?
The protanated acids are absorbed in the stomach.
In the intestines, non protonated forms are absorbed.
In general, explain the two phases of drug elimination.
First phase has to do with polarizing the drug. (CYP enzymes)
Second phase attaches something that is very insoluble to the drug for elimination.
What does the equation
V= [drug]/ C?
This is the volume of distribution equation and is the amount of the drug in the body / Concentration.
What would a very large volume of distribution suggest?
Would suggest that most of the drug is within the extravascular compartment.
A small one would mean the drug is primarily in the blood.
What does the equation
CL = Rate of elimination / C
mean?
Rate of elimination in relation to drug concentration.
Whats the difference between first order elimination and zero-order elimination?
First order is not saturable, a constant ammount is constantly removed.
Zero order is saturable and only so much can be removed at a given time (alcohol)
In general, how many half lives are needed to rid of a drug?
Generally you need 4-5 half lives to rid the body of a drug.
What does the equation AF = 1/ Fraction lost in one dosing interval?
This is how much of the drug will be accumulated in the body during each dosing interval.
What does the equation ER = CL/Q regard?
This is the effect of first-pass metabolism.
(Clearance) / (Hepatic Blood Flow).
What does the equation Css = Dosing rate/CL regard?
This is the steady state concentration equation. The point at which the elimination of a drug is equal to the bio availability
of a drug.
