Pharm 3 - Drug-Receptor Interaction Flashcards
Define Pharmacokinetics.
The effect the body has on the drug
Define Pharmacodynamic.
The effect of the drug on the body
Define ‘drug’.
a chemical substance that interacts with a bioloigcal system to produce a physiological response
State the 4 main target sites for drugs.
Receptors
Enzymes
Ion Channels
Transport Systems
What are the two types of ion channels?
Voltage gated
Receptor linked
Give an example of a drug that acts on an ion channel.
Local anaesthetics - block the voltage gates sodium channels of nociceptors to prevent conduction of pain signals
Give an example of a group of drugs that act on transport systems.
cardiac glycosides - slows down Na+/K+ pump so more intracellular calcium so increased force of contraction
What are the 3 ways drugs can interact with enzymes?
Enzyme inhibitors
False Transmitters
Prodrugs
Name a common example of an unwanted effect of a drug interaction with an enzyme.
Paracetamol overdose
saturates the microsomal enzymes of the liver
so CP450 breaks it down to form toxic metabolites
Name 3 groups of drugs that are exceptions to the 4 target site rule.
General anaesthetics
Antacids
Osmotic purgatives
Define agonist.
a molecule that binds to a receptor and generates a response
Define antagonist.
a molecule that binds to a receptor but does not generate a response
Define potency.
How powerful a drug is.
What two things is potency dependent on?
affinity and efficacy
Define affinity and efficacy.
Affinity - how willingly the drug binds to the receptor
Efficacy - the ability of the drug to generate a response once bound.