Pharmacodynamics & Pharmacokinetics Flashcards
What is pharmacodynamics?
Pharmacodynamics is the study of how drugs affect the body. Considering the biochemical, molecular and physiological effects.
What is pharmacokinetics?
Pharmacokinetics explores the organisms effect on the drug. Exploring the journey of the substance throughout the body: absorption, distribution, metabolism, excretion.
What are the 4 stages of pharmacokinetics?
The 4 stages of pharmacokinetics: ADME. Absorption, Distribution, Metabolism, Excretion.
Describe ABSORPTION
ABSORPTION: How the drug moves from the administration site to distribution .
Describe DISTRIBUTION
DISTRIBUTION: How the drug travels via the bloodstream to other tissues in the body.
What does TDM stand for?
TDM stands for therapeutic drug monitoring
Define EFFECT
EFFECT: The type of response produced by the drug
Define ACTION
ACTION: how and where the effect is produced
Give 3 examples of dietary related elements that have a pharmacological effect
3 EXAMPLES of dietary related elements with a pharmacological effect: Caffeine (for alertness), Glucose (for energy), Heavy meal (sedation)
Give TWO examples of dietary elements that can interact with medicines
GRAPEFRUIT and ALCOHOL are dietary elements that can interact with medicines
Define AFFINITY
AFFINITY: how tightly a substance binds to a receptor
Define LIGAND
LIGAND: molecules that bind to a receptor
If AFFINITY is HIGH, is MORE or LESS drug required?
If AFFINITY is HIGH, LESS drug is needed.
If AFFINITY is LOW, is MORE or LESS drug required?
If AFFINITY is LOW, MORE drug is needed.
What is there a risk of if more drugs are taken?
If more drugs are taken there is a greater risk of side effects and toxicity.
Receptor
Receptor:
* Target molecule that a ligand binds to to produce a specific effect
* A unique recognition site for a specific ligand
* Macromolecule
* Most are proteins
* Found on cell surface, cytoplasm or nucleus
Transduction
Transduction:
* A chain of events that produces a particular effect after a ligand binds to a recptor
Non-receptor targets
Non-receptor targets:
* Targets for antacids and gaseous anaesthetics
* Targets for drugs that do not use receptors
Intrinsic activity
Intrinsic activity:
* A measure of the agonists ability to generate an activating stimulus and produce a change in cellular activity
* The effect you can see/measure
Potency
Potency:
* Concentration required for 50% of the maximal response to be expressed
Occupancy theory
Occupancy theory:
* The more receptors occupied the greater the response
* Not always true
Spare receptors
Spare receptors
* Maximum effect can be seen before all receptors are bound
Threshold
Threshold
* Some ligands can bind to the receptor BEFORE producing a response
The smaller the dissociation constant the _______ the binding
The smaller the dissociation constant the tighter the binding
