Pharmacology Flashcards
What is pharmacodynamics?
Action of drug on the body, where the drug interacts and at which particular sites.
What is pharmacokinetics?
Action of body onto the drug, how it’s absorbed, excreted, and its movement around the body.
Define drug.
A single substance that can be a constituent of medicine and produces a physiological effect when administered.
Define medicine.
A chemical preparation that contains one or more active constituents (drugs) with additives to elicit a therapeutic effect.
What is a ligand?
A substance which binds to a receptor.
What does endogenous mean?
Found in the body.
What does exogenous mean?
Found outside of the body.
What is an agonist?
Causes activation of a receptor and is a drug with high affinity and high intrinsic activity.
What is an antagonist?
Inhibits a receptor and is a drug with high affinity but no intrinsic activity.
Define therapeutic index.
Ratio that indicates the relative safety of a drug, calculated as lethal dose/effective dose.
What are pro-drugs?
Inactive precursors that are metabolised to their active forms.
What are enteric/lipidic-coated drugs?
Oral drugs with a protective barrier against the acidic nature of the stomach.
What are the 5 rights of medication administration?
- Right drug
- Right patient
- Right dose
- Right time
- Right administer
Why are additives added to medicines?
- Ease of administration
- Preservation for longer shelf life
- Enhancer for absorption, solubility, or viscosity
- Colouring for attractiveness
- Flavour for children
What happens when first messengers interact with target cells?
They cause the release of secondary messengers (chemicals) such as intracellular enzymes, calcium, cAMP, cGMP, and intracellular lipids.
What are common sites of action in pharmacodynamics?
- Ion channels
- Voltage-gated ion channels
- Carriers (transport proteins)
- Receptors
- Enzymes
What are ligand-gated channels?
Channels that react (open/close) when a ligand binds to them.
What is a full agonist?
A drug that produces a maximal response.
What is a partial agonist?
A drug that produces less of a response compared to a full agonist.
What are competitive antagonists?
Antagonists that compete with agonists for the same binding sites.
What are non-competitive antagonists?
Antagonists that bind to other sites than the endogenous ligands/agonist binding site.
What factors affect drug-receptor interaction?
- Drug concentration
- Drug affinity
- Drug action at receptor
- Mechanisms terminating drug action
- Presence of other drugs
- Availability of receptor binding site
- Drug selectivity
What is the difference between reversible and irreversible drugs?
Some drugs are reversible or irreversible, causing a prolonged pharmacological effect.
