Pharmacology Flashcards
What is pharmacology?
The study of the action of drugs on the function of living systems
What is pharmacodynamics?
What the drug does to the body
What is pharmakinetics?
What the body does to the drug
What are protein targets for drug binding?
Receptors
Ion channels
Enzymes
Transporters
Why do we have receptors?
Primarily for the purpose of cell to cell communication
What is a receptor?
A recognition molecule for a chemical mediator through which a response is transduced
What is the three parts of the receptor structure?
Extracellular domain- ligand binding sites
Transmembrane Domain- Anchors protein in membrane
Intracellular Domain-Interacts with effector mechanisms
What are the steps of signal transduction?
Signal
Reception
Transduction
Response
What is an example of a very slow signal receptor?
Nuclear receptors
What is a ligand?
Any chemical that binds to a receptor
What is an agonist?
A drug that binds to a specific site on a receptor, mimics the effect of the endogenous ligand for that site
What is an antagonist?
A drug that binds to a specific site on a receptor, blocks the effect of the endogenous ligand on the same or different site as ligand
Do agonists have affinity and efficacy?
Yes both
Do antagonists have affinity and efficacy?
They have affinity but they lack efficacy
What is affinity?
Affinity is a measure of the strength of association between ligand and receptor
What is efficacy?
Efficacy is a measure of the ability of an agonist to evoke a cellular response
What is an example of a slow signal receptor?
Cytokine Receptors
What may cause drug variability?
Sex
Age
Ethnicity
Liver Function
Pregnancy
What is the difference between local and general anaesthetic?
General- Loose consciousness and sedates whole body
Local- Sedates a local area and remain consciousness
Compare the half life of esters and amides?
Esther’s are metabolised quickly which causes a shorter effect (half life)
Amide metabolise slower and have a longer half life
What 3 states do Na+ channels exist in?
Resting, open and inactivated
How does the conduction of a nerve AP come about?
Opening of voltage gated Na+ channels, rapid influx of Na+ to depolarise the cell
Where do local anaesthetics bind to in the cell?
Intracellular side of the Na+ channel
How does local anaesthetics prevent Na+ influxes?
Blocks channel and stabilises it in inactivated confirmation
What does the aromatic group of a local anaesthetic influence?
Hydrophobicity of drug
What does the amide group of a local anaesthetic influence?
The charge on the drug
What pKa values do local anaesthetics range from?
7.6-9
Why are local anaesthetics often given with vasoconstrictors?
Less blood loss
Stop going into systematic circulation
What are the main things we want to know about the drug?
What it does?
Potency
Selectivity
What is potency?
A measure of the dose of a drug at which it is effective
