L1 What is Pharmacology?

• What is toxicology?


  It is the branch of pharmacology that focuses on the harmful effects of chemicals, including drugs.
• What does therapeutics refer to?


  It refers to the medicinal use of drugs to treat or relieve the symptoms of disease.
• Why is it important to note that not all drugs are medicines?


  Because some drugs may not have therapeutic effects or may cause harm.
• What is pharmacy concerned with?


  It is concerned with how drugs are formulated and dispensed for use as medicines.
• What does pharmacology study?


  It studies drugs, their mechanisms of action, effects, discovery, design, development, and interactions with organisms.
• How is a drug defined?


  A drug is a chemical substance of known structure that produces a biological effect when administered to a living organism.
• How many names do therapeutic drugs typically have?


  They typically have at least three names: chemical name, common name, and proprietary (trade) name.
• What is an example of a common name for a drug?

  Ibuprofen
• How are drugs sometimes grouped?

  They are grouped according to therapeutic use or mechanism of action.
• What is ibuprofen classified as?


  Ibuprofen is classified as a cyclooxygenase inhibitor that acts as an analgesic.
• How do drugs produce their effects?

  Drugs mimic or block the actions of endogenous molecules and must be bound to work.
• What are the molecular targets that most drugs bind to?


  Most drugs bind to important proteins such as receptors, enzymes, ion channels, and transporters.
• What is meant by the term "ligands"?


  Ligands are small drug molecules that bind to large target proteins.
• What do modern computer modeling techniques allow in drug design?


  They allow drugs to be designed in silico.
• What factors govern how well a drug fits into its binding site?


  The size and flexibility of the drug govern how well it fits into its binding site.
• What types of bonds do most drugs use to bind to their target proteins?

  Most drugs bind reversibly through hydrophobic and hydrogen bonds, plus weaker van der Waals interactions.
• What is specificity in drug-protein interactions?


  Specificity refers to the precise way a drug binds to a protein target.
• Why must a drug be selective in its action?


  To be therapeutically useful, a drug must not cause severe side effects while treating a condition.
• What is pharmacodynamics (PD)?


  Pharmacodynamics is defined as what the drug does to the body at a molecular level.
• What is pharmacokinetics (PK)?


  Pharmacokinetics is defined as what the body does to the drug, including absorption, metabolism, and distribution.
• What is the significance of PK/PD studies?


  They provide a true understanding of a drug's effectiveness by considering both pharmacodynamics and pharmacokinetics together.
• What does ADME stand for in pharmacokinetics?


  ADME stands for Absorption, Distribution, Metabolism, and Excretion.
• How does absorption influence drug effectiveness?


  Absorption determines how much and how quickly the drug enters the blood plasma.
• What factors influence the absorption of a drug?


  Factors include molecular size, lipid solubility, and chemical stability.
• What are the routes of drug administration?

  • Inhalational
  • Intra-arterial
  • Intracerebroventricular
  • Intradermal
  • Intramuscular
  • Intrathecal
  • Intravaginal
  • Intravenous
  • Nasal
  • Oral
  • Rectal
  • Subcutaneous
  • Sublingual
  • Topical
  • Transdermal
• How are drugs distributed in the body after absorption?


  Drugs are distributed by dissolving in blood plasma and diffusing through tissues in the extracellular fluid.
• What determines a drug's ability to dissolve in plasma or extracellular fluid?


  It is determined by the drug's water (aqueous) solubility.
• What is the Volume of Distribution (Vd)?


  Vd is the volume the drug would occupy if the total amount administered was dissolved in solution at the same concentration as that found in blood plasma.
• If 1000 mg of Drug A is administered intravenously and 70% stays in plasma, what is the concentration in plasma?


  The concentration is $700 \text{ mg in 4 litres or } 175 \text{ mg/l}$.
• If 1000 mg of Drug B is administered intravenously and 30% stays in plasma, what is the concentration in plasma?


  The concentration is $300 \text{ mg in 4 litres or } 75 \text{ mg/l}$.
• What does it mean if a drug has a larger Volume of Distribution?


  A larger Volume of Distribution indicates that more of the drug has left the plasma and entered body tissues.
• Why might we want drugs to stay localized in the body?


  To minimize side effects and ensure targeted action.
• What determines how long the effects of a drug last?

  Metabolism and excretion determine how long the effects of a drug last.
• Where are drugs usually metabolized?


  Drugs are usually metabolized in the liver.
• What is a drug's half-life (t½)?


  A drug's half-life is the time it takes for the plasma concentration to fall by half.
• What is clearance in pharmacokinetics?


  Clearance is the volume of blood plasma cleared of the drug in unit time.
• What factors influence drug metabolism and excretion?


  • Patient's liver health
  • Effectiveness of liver enzymes
  • Activity of metabolites
  • Toxicity of metabolites