Lecture 01, 2

• What is the science of pharmacology primarily concerned with?

  The study of drugs interacting with living systems
• How is a drug defined in pharmacology?

  Any substance causing a change in biological function
• What does pharmacodynamics study?

  The action of drugs on biological systems
• What does the measurement of drug response relate to?

  It relates to dose or concentration of drug
• What are the two main types of mechanisms by which drugs act?

  • Non-receptor mechanisms
  • Change in physical chemical properties
  • Receptor-based mechanisms
  • Involves receptors, enzymes, carrier molecules, ion channels, nuclear receptors
• What is a receptor in pharmacology?

  The part of the cell that binds drugs
• Why are receptors compared to locks?

  Only the right key (drug) fits the lock (receptor)
• What is the principal goal of pharmacological research?

  Understanding binding sites and mechanisms
• How are receptors classified?

  • Based on drug binding
  • Ligand binding to receptors
  • Molecular cloning of amino acid sequences
• What is GTN used to treat?

  Angina and heart conditions
• How does GTN affect blood vessels?

  It widens blood vessels and increases blood flow
• What is a bioassay?

  Measuring activity of a substance on living material
• What does the dose-response relationship describe?

  The relationship between drug concentration and response
• What does pharmacokinetics study?

  • Fate of drugs in the body
  • Rates of absorption, distribution, metabolism, excretion
  • Predicting plasma levels based on dose
• What is the major reason new drugs fail in clinical trials?

  Pharmacokinetics issues
• What are the 5 rights of medication administration?

  • Right medication
  • Right patient
  • Right dosage
  • Right form and route
  • Right time
• What is a therapeutic window?

  Range of doses achieving desired effects safely

  
• What does a narrow therapeutic window indicate?

  Close to toxic dose
• What are the three methods of drug administration discussed?

  1. Continuous infusion
  2. Single daily injection
  3. Multiple daily injections
• What is the effect of continuous infusion on drug concentration?

  Gradual increase stabilising within therapeutic window

  
• How does a single daily injection affect drug concentration?

  Sharp increase followed by gradual decline
• How do multiple daily injections compare to single daily injections?

  Fluctuations stay consistent within therapeutic window
• What are the sources of drugs?

  • Natural sources
  • Synthetic sources
  • Semi-synthetic sources
• What is an agonist?

  A substance that activates a receptor

  
• What does 'affinity' refer to in pharmacology?

  The tendency of a drug to bind a receptor
• What does Emax represent?

  The maximal measured effect of a drug
• What does EC50 indicate?

  The concentration producing half of maximum effect
• What is the Law of Mass Action?

  • Rate of reaction depends on concentration of reagents
  • Describes drug-receptor interactions
  • Assumes reversible binding
• What are the three major factors determining drug response magnitude?

  Number of drug molecules, receptor occupancy, formation rate
• What does the association constant (Ka) represent?

  Drug behaviour in binding to receptors

  
• What does the dissociation constant (Kd) indicate?

  Affinity between drug and receptor
• What does radioligand binding study?

  • Drug ligand and receptor interactions
  • Affinity and density of receptors
  • Does not differentiate between agonist and antagonist
• What does the KD represent?

  Drug concentration to saturate 50% of receptors
• How does a lower KD affect drug affinity?

  Indicates greater drug affinity for receptor
• What does a sigmoidal dose-response curve indicate?

  Relationship between agonist concentration and response

  
• What does EC50 indicate about a drug's potency?

  Lower EC50 means higher potency
• What are the types of agonists?

  • Full Agonists: Reach maximum response (100%)
  • Partial Agonists: Cannot elicit full response even when all receptors are occupied

  
• Why do partial agonists have lower efficacy?

  They cause less activation than full agonists
• What is a bioassay?

  • Method to measure drug activity on living material
  • Can use live animals or tissues
  • Assesses contraction or dilation responses
• What is the purpose of organ baths in bioassays?

  To maintain live tissue with nutrients and warmth