Exam Prep Flashcards
What is a receptor agonist?
An agonists is a drug that activates a receptor and takes the place of the endogenous ligand.
100% efficacy
What is a receptor antagonist?
An antagonist is a drug that binds to a receptor to limit its activity by blocking the binding site of the endogenous ligand to the receptor.
Zero efficacy
Define efficacy
The ability of a drug to produce its biological response
Define potency
How much of the drug is required to produce a response.
PK Antagonism is
Where the antagonist effectively reduces the concentration of the active drug at its site of action by affecting its PK.
PK Agonism is
Where the PK of Drug A is affecting PK of Drug B leading to an increase in activity of Drug B
What are the 2 types of Competitive Antagonism and give a brief description of each.
Reversible competitive antagonism - is when the antagonist competes with the agonist for the same binding site. Maximal response to the agonist can still be achieved but requires higher dosage.
Irreversible competitive antagonism - is when the antagonist dissociates very slowly or not at all from the receptor.
What is Non competitive antagonism?
This refers to antagonist and agonist binding to different receptor at different sites, or one drug inhibits the activity of the other drug by altering cell signalling down stream of the receptor.
What are the different types of drug targets?
Receptors
Enzymes
Ion channels
Transporters
What are the types of receptor proteins?
Ligand gated ion channels
G-protein coupled receptors
Kinase-linked receptors
Nuclear proteins
Factors that influence the passage of drugs across barriers are:
Molecule size
Lipid solubility
Ionisation (if ionised won’t be able to cross membrane due to having low lipid insolubility however, it will be highly water soluble)
How are drugs mostly excreted from the body?
Most commonly in the urine and to a lesser extent in the faeces. Some are exhaled.
What is first-pass metabolism?
The hepatic and intestinal degradation or alteration of a drug taken ORALLY, after absorption, removing some of its active substance from the blood before it enters general circulation.
Drugs that undergo first-pass metabolism will have reduced bio-availability.
List the common modes of drug administration.
Oral Intravenous injections & infusions Intramuscular injections Subcutaneous injections Inhalation Sublingual Application Rectal Other specialised routes eg. joints or spine
Where are drugs most commonly metabolised and what are the consequences?
Liver (if you don’t get that fuuuuck me)
Inactivation of a drug
An increase or change in drug action
Activation of a prodrug
Alteration of drug toxicity
Disorder:
This describes an abnormality of function
Syndrome:
A set of clinical manisfestations that occur together in a condition in which the cause is unknown.
Disease:
Has a well-defined cause, clinical manifestations and a corresponding set of diagnostic and treatment strategies.
Acute:
Describes a condition that develops and resolved quickly.
Chronic:
Describes a condition that develops more gradually and lasts longer.
Aetiology:
Describes the underlying cause.
Epidemiology:
The study of factors that affect the health populations.