Pcol

• Pharmacology


  A branch of science that deals with the study of drugs and their actions on the body
• Pharmacokinetics


  What the body does to the drug
• Pharmacodynamics


  What the drug does to the body
• Pharmacotherapeutics

  A branch of medicine concerned with the cure of a disease and/or relief of symptoms through an appropriate drug treatment
• Toxicology


  The study of adverse (undesirable or untoward) effects of chemicals on living systems from individual cells to complex ecosystems
• Pharmacy


  The science of identification, selection, preservation, standardization, compounding, and dispensing of medicinal substances
• Drugs


  Substances that act on living systems at the chemical or molecular level, substances that can alter the structure and physiologic functioning of man and other animals, articles that are used in the diagnosis, prevention, cure, treatment and mitigation of diseases in man and other animals
• Functional Modifiers


  Pharmaceutical agents that can alter biochemical and physiological activities of the cell
• Replenishers


  Pharmaceutical agents that will add or supplement endogenous compounds which are insufficient
• Diagnostic Agents


  Radiopharmaceuticals that are used to determine the cause of an illness or disorder
• Chemotherapeutic


  Pharmaceutical agents that can kill or inhibit growth of cells that are foreign to the body
• Drug Nomenclature


  Chemical name, Generic name, Brand name
• Prodrugs


  Compounds that, on administration must undergo chemical conversion by metabolic processes before becoming an active pharmacological agent
• Placebo


  Inactive substance or preparation given to satisfy the patient's symbolic need (psychic need) for drug therapy and used in controlled studies to determine the efficacy of medicinal substances
• Sources of Drugs


  • Mineral
  • Animal
  • Plant
  • Semisynthetic
  • Synthetic
• Majority of drugs have molecular weights between 100-1000
• Drugs larger than MW of 1000 do not diffuse readily between membrane compartments
• Drug-Receptor Bond


  Receptors are the molecular components of the body with which a drug interacts to bring about its effects. Receptors are specific for a drug molecule. Drug's shape is complementary to that of the receptor site in the same way that a key is complementary to a lock. Drugs can bind to receptors through variety of chemical bonds
• Movement of Drugs in the body

  In order to reach its target receptors and bring about a pharmacologic effect, a drug molecule must travel from the site of administration and absorption (e.g. GIT) to the site of action (e.g. brain). Drugs will be distributed into different body compartments where it can either be stored, metabolized or excreted
• Pharmacodynamics


  It describes the action of a drug on the body and the influence of drug concentration on the magnitude of the response. It also focuses on the mechanisms of drug action by which their effects were produced
• Signal transduction


  The drug-receptor complex initiates alteration in biochemical and/or molecular activity of a cell by a process called signal transduction. In signal transduction, drugs act as signals and their receptors act as signal detectors
• Receptors

  It is used to denote any target molecule with which a drug molecule has to combine with in order to elicit its specific effect. These are specific drug-binding sites within a cell or on its surface. Drug action is usually thought to begin after a drug has attached itself to some receptor forming now a drug-receptor complex. Only one drug molecule can occupy a receptor at one time
• Site of Action


  The location within the body where the drug exerts its therapeutic effect. When the receptor site for a drug is known, the receptor site becomes the site of action for a particular drug
• Mechanism of Action


  It describes the process by which a drug works on a molecular level in the body to produce pharmacological effect. Based on the drug target sites, the mechanism of action can be broadly classified as protein mediated mechanism and non-protein mediated mechanism
• Protein-mediated MOA


  • Structural proteins (e.g. microtubules and tubulins), Regulatory proteins (e.g. voltage-gated ion channels, carrier or transport proteins, enzymes, receptors)
• Non protein-mediated MOA


  • Colligative mechanism, Direct Chemical interaction, Counterfeit mechanism
• Protein-mediated MOA


  Drug interacts usually in a Lock and Key fashion
• Non Protein-mediated MOA


  No binding of drugs to the active site of proteins, pharmacologic effect is produced by other means without the involvement of a protein
• Non Protein-mediated MOA


  1. Colligative mechanism

  2. Direct Chemical interaction

  3. Counterfeit mechanism
• Colligative mechanism


  Elicits pharmacologic effect under the influence of the presence and amount of solute, e.g. Mannitol as osmotic diuretic increases osmotic pressure within the lumen of the kidney tubules causing enhanced water diuresis and sodium/potassium excretion
• Direct Chemical Interaction


  Produces effect through chemical reactions such as Neutralization and Chelation, e.g. mechanism of antidotes
• Direct Chemical Interaction


  • Heparin SO4 + Protamine SO4 -> SALT
  • Copper + Penicillamine -> COMPLEX
• Salt form and complex compounds are readily excreted from the systemic circulation
• Counterfeit mechanism


  Produces effect through false incorporation by mimicking a particular endogenous compound, e.g. Antimetabolites are "cytotoxic" drugs because they kill cells by mimicking the molecules that a cell needs to grow
• Receptors


  Macromolecules involved in chemical signaling, may be located on the cell membrane surface or within the cytoplasm
• Ligands


  Molecules (e.g., neurotransmitters, drugs, hormones) that bind to a receptor
• Ligand


  • Drug's affinity: ability of the drug to bind or occupy a receptor
  • Intrinsic activity: ability of the drug to activate receptors and evoke response
• Agonist


  Possesses high affinity and intrinsic activity, binds to a receptor and produces a biologic response, can mimic the response of the endogenous ligand or elicit a different response
• Types of agonist


  • Full agonist
  • Partial agonist
  • Inverse agonist
• Full agonist


  A drug that binds to a receptor producing maximum activation that mimics the response to the endogenous ligand