Principles

Question 1

What is pharmacology?

Answer 1

study of drug action and its influence on physiological function

Question 2

What is therapeutic effect?

Answer 2

effect prescribing a drug has on a patient

Question 3

What are the drug targets?

Answer 3

receptors
enzymes
ion channels
transport proteins

Question 4

How does selectivity of a drug affect its dosage?

Answer 4

dose of drug is administered is related to the selectivity of the drug

Question 5

What are the drug receptor interactions?

Answer 5

electrostatic
hydrophobic
covalent - typically irreversible
stereospecific

Question 6

What is the difference between antagonist, partial agonist and full agonit?

Answer 6

antagonist - block receptor by producing no response when they bind
partial agonist - affinity for receptor but sub maximal efficacy
full agonist - affinity for receptor and maximal efficacy

Question 7

What is affinity?

Answer 7

strength of the drug receptor complex

Question 8

What is efficacy?

Answer 8

ability of individual drug molecule to produce effect once bound to a receptor

Question 9

What is potency?

Answer 9

refers to conc or dose of drug needed to produce defined effect, standard measure is EC50 or ED50

Question 10

What are the major pharmacokinetic factors?

Answer 10

absorption - passage of drug from site of administration to plasma

distribution
metabolism
excretion

Question 11

What is bioavailability?

Answer 11

fraction of the initial dose that gains access to systemic circulation

Question 12

Where is a weak base drug least likely to be absorbed?

Answer 12

in the stomach because of low pH

Question 13

Where are weak acids least likely to be absorbed?

Answer 13

from the blood

Question 14

What carrier systems are most important?

Answer 14

those in the renal tubule
biliary tract
blood brain barrier

Question 15

How do drugs move around the body?

Answer 15

through bulk flow transfer - in the blood stream or

diffusional transfer across short distances

Question 16

How do drugs diffuse?

Answer 16

through simple diffusion
diffusion across aqueous pores
carrier mediated transport
electrochemical gradient

Question 17

What factors affect distribution?

Answer 17

regional blood flow - diff organs receive diff cardiac output
plasma protein binding - albumin binds acidic drugs, determines on bioavailability of the drug
capillary permeability - lipid soluble drugs can diffuse, others cant
tissue localisation - lipid solube and water soluble localise at different places due to equilibrium

Question 18

What is a major metabolic tissue?

Answer 18

liver - has cytochrome p450 enzymes for drug metabolism

Question 19

What are the phases of drug metabolism?

Answer 19

phase 1 - introduce reactive groups to drug

phase 2 - add conjugate to reactive groups

Question 20

How do we deal with drugs that are passed through hepatic metabolism?

Answer 20

because the drug is heavily metabolised in the livr, little will reach the systemic circulation. administer a higher dose to ensure enough reaches systemic circulation

Question 21

How are drugs excreted in the kidney?

Answer 21

glomerular filtration
active tubular secretion
passive diffusion across the tubular epithelium

Question 22

What is biliary excretion most commonly used for?

Answer 22

2 glucuronide metabolites however enterohepatic recycling can occur which can prolong the drug effect