Intro to Pharmacology Flashcards
What is a drug?
Chemical substance of known structure, other than a nutrient or essential dietary ingredient, which when administered to a living organism, produces a biological effect
What is pharmacology?
The study of mechanisms by which drugs affect the function of living systems
- Tailoring therapeutic choices to an individuals genotype
What is a bioassay?
Where the concentration or potency of a substance is measured by the biological response it produces
Why are bioassays used?
- Measure pharmacological activity of new or chemically undefined substances
- Investigate function of endogenous mediators
- Measure drug toxicity and unwanted effects
What are the fundamental principles of pharmacology?
- Drug action must be explicable in terms of conventional chemical interactions between drugs and tissues
- Drug molecules must be ‘bound’ to particular constituents of cells
- Drug molecules must exert some chemical influence on one or more constituents of cells in order to produce a pharmacological response e.g. must cause an increase or decrease of something in a cell
What classes of proteins are targeted by drugs?
- Enzymes
- Transporters
- Ion channels
- Receptors
What is a ligand?
Any molecule that binds to a receptor - may be an agonist or antagonist
What are agonists?
Drugs or chemical mediators that bind to a receptor producing a response
What are antagonists?
Drugs that prevent or inhibit the response of an agonist
May bind to the receptor but do not elicit a response
What is intelligent drug design?
- Driven by knowledge of the ligand binding site
- Understanding how we can create drugs to mimic agonists or prevent interactions from occurring
- Allows more selective drug development
What causes side effects?
- Caused by drugs which lack specificity
- Many receptors are found in more than one organ
- Drugs will bind to receptors wherever they are located
What is CAR T immunotherapy?
Uses contact-dependent signalling to kill cancer cells
Chimeric Antigen Receptor - engineered receptor designed to recognise cancer cells
- Inserted into genome of patient T-cells to create ‘live’ drug
How can drugs acting on receptors affect paracrine signalling?
- Mast cells located under skin detect allergens
- Activated mast cells secrete mediators e.g. histamine - acts locally to produce vasodilation and activate neurons involved in itch
- Many allergy medicines contain drugs which block histamine receptors
How can drugs acting on enzymes affect paracrine signalling?
- Eicosanoids e.g. prostaglandins are lipid-derived paracrine mediators - cause inflammation
- NO - relaxation of SM cells and vasodilation allowing more blood
- Viagra - inhibits enzyme for cGMP breakdown, prolonging NO action
How can drugs affect neurotransmission?
Block VG Na+ channels - prevent AP generation, used as local anaesthetics, e.g. lidocaine
Target NT release - toxins can inhibit e.g. Botulinum Toxin cleaves proteins in synaptic machinery
Target transporters found on cell membrane and vesicle membrane
Drugs of abuse - e.g. amphetamines indirectly increase noradrenaline by displacing it from vesicles
Therapeutic drugs - target and block transporters, prevent NT reuptake, alleviate symptoms of neurological conditions
