PED1003 PHARMACOLOGY LECTURE 4 - 6 EXAM QUESTIONS
AND ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
When is an IV used to administer a drug? (3 reasons)
- when a rapid onset of action is needed
- when high dose control is required
- when a drug is poorly absorbed or metabolised in GI tract
What are the 3 types of drug injections available?
Intravenous
Intramuscular
Subcutaneous
first pass metabolism
the substance degradation of an orally administered drug caused by enzyme
metabolism in the liver before the drug reaches the systemic circulation
What is enterohepatic circulation?
Circulation of bile acids from liver to gut and back to the liver
What is Tmax?
Time taken to reach maximum drug concentration
What is bioavailability?
Fraction of administered drug that is absorbed and therefore available to have an effect
in the body (the rest is lost via first pass metabolism)
Equation for bioavailability (F)?
, AUC = area under curve
What are the 3 factors effecting the distribution of a drug?
- Blood perfusion of the tissue or organ
- Ability to cross cell membrane
- Plasma protein binding ability
What is the blood brain barrier?
A continuous layer of epithelial cells that makes the brain inaccessible to many drugs
What must all psychoactive drugs be able to do?
Penetrate the blood brain barrier
Most drugs in the blood are bound to what?
Plasma proteins
Albumin binds mostly to what drugs?
acidic drugs
Alpha1 glycoprotein (AAG) binds mostly to what drugs?
Basic drugs
How many drug binding sites are there per albumin molecule?
2
What is apparent volume of distribution?
proportionality constant that relates the amount of drug in the body to the serum
concentration
How do you calculate apparent volume of distribution (Vd)?
(total amount of drug administered) / Plasma concentration
What are the units of Vd?
AND ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
When is an IV used to administer a drug? (3 reasons)
- when a rapid onset of action is needed
- when high dose control is required
- when a drug is poorly absorbed or metabolised in GI tract
What are the 3 types of drug injections available?
Intravenous
Intramuscular
Subcutaneous
first pass metabolism
the substance degradation of an orally administered drug caused by enzyme
metabolism in the liver before the drug reaches the systemic circulation
What is enterohepatic circulation?
Circulation of bile acids from liver to gut and back to the liver
What is Tmax?
Time taken to reach maximum drug concentration
What is bioavailability?
Fraction of administered drug that is absorbed and therefore available to have an effect
in the body (the rest is lost via first pass metabolism)
Equation for bioavailability (F)?
, AUC = area under curve
What are the 3 factors effecting the distribution of a drug?
- Blood perfusion of the tissue or organ
- Ability to cross cell membrane
- Plasma protein binding ability
What is the blood brain barrier?
A continuous layer of epithelial cells that makes the brain inaccessible to many drugs
What must all psychoactive drugs be able to do?
Penetrate the blood brain barrier
Most drugs in the blood are bound to what?
Plasma proteins
Albumin binds mostly to what drugs?
acidic drugs
Alpha1 glycoprotein (AAG) binds mostly to what drugs?
Basic drugs
How many drug binding sites are there per albumin molecule?
2
What is apparent volume of distribution?
proportionality constant that relates the amount of drug in the body to the serum
concentration
How do you calculate apparent volume of distribution (Vd)?
(total amount of drug administered) / Plasma concentration
What are the units of Vd?
