Pharmacology Flashcards
What is First Order Kinetics?
When a constant PROPORTION of the drug is eliminated per unit time
What is Zero Order Kinetics?
When a constant AMOUNT of drug is eliminated per unit time
What is Bioavailability
The amount of administered drug that reaches the systemic circulation unaltered
What is Adsorption?
The process of transfer from the site of administration to the general or systemic circulation
What is Distribution?
The process by which the drug is reversibly transferred from the general circulation to the tissues as blood concentration increases. It then returns to the general circulation
What is volume distribution?
The theoretical VOLUME that would be necessary to contain the total amount of administered drug at the same concentration it is held in the plasma.
= total amount of drug in body
= dose/plasma
What is elimination?
The removal of drug activity from the body via metabolism or excretion
METABOLISM.
What happens in Phase 1?
DEGRADATIVE
The change to a polar metabolism by unmasking/adding a functional group e.g. OH
METABOLISM
What happens in phase 2?
SYNTHETIC
Conjugation —> the formation of a covalent bond makes drug less active e.g. glucuronic acid
What are adverse drug reactions?
Unwanted or harmful reactions following administrations of a drug or combination of drugs under normal conditions of use and is suspected to be related to one drug.
What is a side effect?
Unwanted effect of a drug
THOMPSON CLASSIFICATION.
What is a type A reaction?
Augmented pharmacological.
Predictable and dose-dependent, common
e.g. morphine and constipation
THOMPSON CLASSIFICATION.
What is a type B reaction?
Bizarre and idiosyncratic
Non-predictable/dose-dependent
e.g. Penicillin and anaphylaxis
THOMPSON CLASSIFICATION.
What is a type C reaction?
Chronic
e.g. steroids and osteoporosis
THOMPSON CLASSIFICATION.
What is a type D reaction?
Delayed
Malignancy after immunosuppression
THOMPSON CLASSIFICATION.
What is a type E reaction?
End of treatment
Opioid withdrawal
THOMPSON CLASSIFICATION.
What is a type F reaction?
Failure
What is affinity?
How well a drug can bind to another receptor (speed and strength)
What is potency?
The amount of drug needed to produce a given effect (affinity and number of receptors)
What is efficacy?
The maximum effect that a drug can produce regardless of dose (E-max)
What is an agonist?
A compound that binds to a receptor and activates it
What is an antagonist?
A compound that binds to a receptor and inhibits it
DRUG INTERACTIONS
What is meant by “Physiochemical?”
When the drugs physically react with one another e.g. paracetamol and activated charcoal adsorption
What is pharmacodynamics?
What the drug does to the body e.g. Beta blockers reduce the HR
PHARMACODYNAMICS
What is meant by summation?
The effect of 2 drugs together
1+1 = 2
So you can give half of each and get the same response
PHARMACODYNAMICS
What is meant by synergism?
Where 2 drugs are put together, and the sum of their parts is greater than is expected e.g. paracetamol and morphine
1+1 > 2
PHARMACODYNAMICS
What is meant by antagonism?
Where 2 drugs work against each other e.g. morphine and naloxone
1 + 1 = 0
PHARMACODYNAMICS
What is meant by potentiation?
Where 2 drugs interact, and 1 drug makes the other drug more “powerful” e.g. probenecid and penicillin
1 + 1 = 1.5, A–> B but not same as B–> A
What is pharmacokinetics?
The effect the body has on the drug
What type of molecule are drug targets usually?
Proteins such as receptors, enzymes, transporters and ion channels
Give an example of ligand-gated receptors
Nicotinic ACh receptors
Give an example of something that targets G-protein coupled receptors
Beta adrenoreceptors
Give an example of kinase-linked receptors
Growth factors
Give an example of nuclear receptors
Steroid receptors
ANAPHYLAXIS AND HYPERSENSITIVITY
What is a Type I reaction?
IgE mediated response after previous exposure e.g. anaphylaxis from bee stings, nuts
ANAPHYLAXIS AND HYPERSENSITIVITY
What is a Type II reaction?
Antibody (IgG, IgM) mediated against drug
ANAPHYLAXIS AND HYPERSENSITIVITY
What is a Type III reaction?
Immune complex mediates i.e. antigen and antibody e.g. SLE, hypersensitivity pneumonitis
ANAPHYLAXIS AND HYPERSENSITIVITY
What is a Type IV reaction?
Delayed/T cell-mediated e.g. chronic graft rejections
How do you manage anaphylaxis?
ABC Stop drug ADRENALINE Oxygen IV fluids IV anti-histamine and hydrocortisone
What is tolerance?
When down-regulation of a receptor occurs so you need a higher dose of the drug to achieve the same response
What do you give to treat an opioid overdose?
Naloxone
