Lecture 1 - Intro to Pharmacology Flashcards
Define Pharmacology
The science of drugs; their mechanisms of action, how their effects can be measured, their discovery, design and development, their actions on the organism and the actions of the organism on them
Define Therapeutics
The medicinal use of drugs to treat or relieve the symptoms of
disease.
Define Pharmacy
How drugs are formulated and dispensed for use as medicines.
Includes the law governing the medicinal use of drugs
Define Toxicology
That branch of pharmacology that focusses on the harmful effects of chemicals, including drugs
Define Drug
a chemical substance of known structure, other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect.
How are drugs named?
- 3 names: chemical, common, proprietary
- category: according to therapeutic use e.g. antihypertensive
- mechanism of action e.g. inhibitor
What type of molecules are drugs?
Drugs are exogenous molecules that mimic or block the actions of endogenous molecules
4 target proteins for drugs
- receptors for NT or hormones
- enzymes
- ion channels
- carrier or transporter molecules
What are steric factors
e.g. size and flexibility of the drug
effects how well drug binds to binding site
chemical bonds to bind reversibly
hydrophobic and H bonds and weal VDW
chemical bonds to bind irreversibly
covalent interactions
Define selectivity
for a drug to be used therapeutically it must be selective in its action
not cause any side effects
How to achieve selectivity?
design drug that binds with high specificity to target protein and no other
Define Pharmacodynamics [PD]
what the drug does to the body
Define Pharmacokinetics [PK]
what the body does to the drug
What does ADME stand for?
Absorption, Distribution, Metabolism, Excretion
What are ADME?
critical elements of pharmacokinetics [PK] that can be influenced by drug
Define absorption
determines how much and how quickly the drug enters the blood
what 3 chemical properties of a drug is absorption influenced by?
- molecular size
- lipid solubility
- chemical stability
How are the drugs distrubted?
through blood plasma and dissolve in ECF
What is the ability to dissolve determined by?
Water solubility
4 things that interfere with distribution
- circulation
- drug binding to protein in plasma - not free to produce effect
- drug partition into fat stores- not active
- access to organ e.g. BBB
How to measure impact of factors on distribution?
measure Volume of Distribution [Vd]
Define Volume of Distribution
volume drug would occupy if total amount dissolved in solution at the same conc. as found in blood plasma
What does it mean if a drug has systematic actions?
it influences the whole body
What happens if a drug remains in a localised compartment?
minimises side effects
what does metabolism and excretion determine?
determines how long the effects of the drug lasts
Where are drugs metabolised?
The liver
What are drugs metabolised into?
Metabolites
Where are the drugs excreted?
The kidney
4 things to consider for metabolism and excretion
- health of liver
- effectiveness of liver enzymes
- are metabolites of drug active
- are metabolites toxic
main route for excretion
urine
other routes for excretion
faeces
sweat
bile
breath
Define drug’s half-life
time taken for conc. of plasma to fall by 1/2
Define clearance
volume of BP cleared by drug in unit time
e.g. ml of plasma/min
