Phamacology Flashcards
Define pharmacology
Study of the actions and effects of chemicals on body and body on chemicals
What are the main 2 components of pharmacology
Pharmacokinetics
Pharmacodynamics
Define pharmacodynamics
Drugs effect on body
Define pharmacokinetics
Bodys effect on drugs
3 considerations of drugs in terms of pharmacodynamics
interaction with …, what about drug, modifies?
Interaction with cells
Effect of drug concentration on body
Drug modifying disease
3 properties of drugs
Affinity
Efficacy
Potency
Define affinity
Ability of drug to bind to receptor
Define efficacy
Ability of drug to induce an response
Define potency
Amount of drug required to illicit desired response
What is the equation for potency
Affinity + efficacy
List 4 families of receptors for drugs
Ligand gated ion channels
G coupled protein receptors
Enzyme linked receptors
Intracellular receptors
List 4 drug action sites
Enzymes
Receptors
Carriers
Ion channels
What are 2 ways things a drug can act as?
As an agonist or an antagonist
List 3 types of agonists
Full agonist
Partial agonist
Inverse agonist
List 3 types of antagonists
Antagonists
Competitive antagonists
Non-competitive antagonists
Define a full agonist drug
Drug that binds to receptor to initiate a response
What do agonist drugs mimic?
Body’s function
What are 2 features of a full agonist
High affinity and efficacy
Define a partial agonist drug
Drug that binds to a receptor to initiate a response but without the efficacy of a full agonist
Partial agonists can act as what when given with a full agonist?
Competitive agonist
Define a inverse agonist drug
Drug that binds to a receptor to initiate the opposite response e.g. naloxone on opioid receptors
Define a antagonist drug
Drug that binds to a receptor to initiate no response/prevent response from occurring
Define a competitive antagonist drug
Drug that binds to same receptor as another drug/ligand thus competes for receptor site
Define a non-competitive antagonist
Drug that binds to a different site on receptor leaving the receptor ineffective
What do dose response curves show?
Body’s response to drug against logarithmic dose
On a dose response curve graph what does the X axis demonstrate about which feature of a drug (i.e. efficacy, potency, affinity)?
(which direction is highest to lowest)
X axis demonstrates a drugs potency from highest to lowest (left to right)
On a dose response curve graph what does the Y axis demonstrate about which feature of a drug (i.e. efficacy, potency, affinity)
(which direction is highest to lowest)
Y axis demonstrates a drugs efficacy and affinity from lowest to highest (bottom to top)
True or false, modified forms/doses of drugs should never be crushed or chewed?
True
3 considerations of drugs in regards to pharmacokinetics
route, time, exit
Process of absorption from administered route
Period between administration and effect
Process of elimination from body
What are the 4 stages of pharmacokinetics?
ADME Absorption Distribution Metabolism Excretion
Define absorption
from where to where
Transfer of drug from administered site into systemic circulation
What % of drug is absorbed in how many hours given via oral route?
75%
1-3 hours
What 3 cause the loss of 25% of a drug administered orally?
GIT acid
Enzymes
1st pass metabolism
First pass metabolism only occurs when drugs are taken orally?
True
List 6 factors that effect oral absorption of a drug
Particle size Formulation Enzymes and pH of GIT GIT motility Physiochemical factors e.g. salt form Food eaten
What would inactivate a drug to mean that it couldn’t be given orally?
Drugs left inactive due to first pass metabolism
Define a depot and what does it mean for speed of absorption?
Drug given in a suspension
Allows for slow sustained absorption
What type of substance does a specialised depot come in and what does does this mean for absorption?
Oily substance
Slow absorption
Drugs given IM in an aqueous solution have fast or slow absorption?
Fast
Which 2 routes can suspensions be given into?
IM or subcut
What is the bioavailability of a drug given IV?
100%
Define distribution
Process where drug is reversibly transferred
Name 2 methods of distribution
clue: transfer, distance
Bulk flow transfer - in blood
Diffusion transfer - molecule by molecule through phospholipid bilayer
How are drugs reversibly transferred?
By binding to plasma proteins
Name 2 proteins that help transfer drugs
Albumin
Glycoproteins
True or false, drugs are chemically inert when bound to plasma proteins
True
List 4 methods by which drugs cross cell membrane
Passive diffusion
Facilitated diffusion
Active transport
Pinocytosis
During passive diffusion what concentration do drugs move from to?
High to low concentration
What drug action site facilitates passive diffusion?
Ion channels
What drug action site facilitates facilitated diffusion
Protein carriers
Which is quicker facilitated or passive diffusion?
Facilitated
What does active transport allow for in terms of drug concentration?
Movement of drug against concentration gradient
What does a drug need to be soluble in to be able to cross the blood brain barrier?
Lipid soluble