chapter 1

• Pharmacology comes from the word "pharmacon," which means drug, and "logi," which means study
• Pharmacology is the study of drugs
• Drugs have at least three names:

  • Chemical name: gives the composition or elements in the drug's structure
  • Generic name: abbreviation of the chemical name
  • Brand name: given by the manufacturer and protected by copyright
• Drugs can be classified based on pharmacologic class or family, grouping them if they share similar characteristics

  • Example: Beta blockers like metoprolol, propranolol, atenolol block beta receptors
• Therapeutic class categorizes drugs based on their therapeutic use

  • Example: Anti-hypertensives include beta blockers and angiotensin receptor blockers (ARBs)
• Examples of therapeutic classes:

  • Anti-hypertensives: include beta blockers and ARBs like losartan
  • Calcium channel blockers (CCBs): drugs like amlodipine
  • Diuretics: first-line drug for hypertension
  • ACE inhibitors: drugs like captopril
  • NSAIDs: used for gout and inflammation
  • Corticosteroids: used for various conditions
  • Antibacterial antibiotics: include penicillins, cephalosporins, and fluoroquinolones
• Sources of drugs:

  • Plants: examples include opium poppy for morphine
  • Animals: insulin from pigs
  • Minerals: magnesium sulfate, aluminum hydroxide
• Phytochemicals in plants responsible for pharmacologic action:

  • Alkaloids: active components like nicotine and morphine
  • Glycosides: plant constituents with sugar in their structure, like digoxin
• Plants as drug sources:

  • Gums have the ability to attract and hold water and are used as pharmaceutical excipients
  • Resins, like amber and copal, are by-products from volatile oils processes
  • Oils:
  • Two types of oils in pharmacognosy: volatile and fixed oils
  • Volatile oils evaporate, while fixed oils leave grease-like residue on paper
  • Examples of fixed oils: olive oil, coconut oil
  • Examples of volatile oils: peppermint oil
  • Oils used to make perfumes are volatile oils
• Animal-derived drugs:

  • Insulin is a hormone obtained from animals
  • Enzymes like pancreatin and pepsin are derived from animals
  • Vaccines are obtained from microorganisms and can be killed, modified, or attenuated
• Mineral-derived drugs:

  • Iron, iodine, Epsom salt
• Synthesized drugs:

  • Drugs like insulin can be synthesized inside the body
  • Drugs obtained from outside sources are called xenobiotics
• Poisons and toxins:

  • Poisons are harmful substances with exclusively harmful effects
  • Toxins are poisons of biological origin, differentiating them from inorganic poisons
• Physical nature of drugs:

  • Drugs can exist in solid, liquid, or gas states
  • Examples: solid drugs like aspirin, liquid drugs like nicotine, and gas drugs like ethanol
• Drug size and weight:

  • The smallest drug is lithium, and the largest drug is heparin
  • Most drugs fall within a molecular weight range of 100 to 1000
• Drug-receptor bonds:

  • Covalent bonds are strong and often irreversible, like aspirin with cyclooxygenase enzyme
  • Electrostatic bonding involves ionic molecules with weaker hydrogen bonds
  • Hydrophobic bonds involve lipid-soluble drugs and lipid receptors
• Rational drug design:

  • Pharmacists and chemists design drugs based on receptor properties and drug structure
  • They modify drug structures to bind to specific receptors and cause desired effects
• Investigational New Drug (IND) and clinical trials:

  • Phase 1 clinical trials involve healthy volunteers to establish the safety of new drugs
• Clinical trial phases:

  • Phase 1: Establishing the safety of a new drug using healthy volunteers
  • Phase 2: Establishing efficacy in a small group of patients
  • Phase 3: Confirming efficacy and monitoring adverse reactions in a larger group of patients
  • Phase 4: Post-marketing surveillance for long-term effects and rare adverse reactions
• Factors influencing drug absorption:

  • pH interaction with basic substances affects absorption
  • Blood flow to organs affects absorption
  • Contact time in the intestines affects absorption
  • Presence of glycoproteins in the body affects absorption
  • Bioavailability is the rate and extent of drug absorption into the bloodstream
• Bioequivalence:

  • Two drugs are bioequivalent if they have the same bioavailability and achieve similar blood concentrations
  • Therapeutic equivalence requires the same dosage form, active ingredient, and route of administration
• Drug metabolism:

  • Major site of metabolism is the liver
  • Metabolism can lead to drug inactivation or activation (prodrugs)
  • Exceptions to prodrugs include captopril, which is active without metabolism
• Drug excretion:

  • Major site of excretion is via the kidneys
  • Drugs can also be excreted via stool, sweat, and breast milk in lactating mothers
• Pharmacology comes from the word "pharmacon," which means drug, and "logi," which means study
• Pharmacology is the study of drugs
• Drugs have at least three names:

  • Chemical name: gives the composition or elements in the structure of the drug
  • Generic name: abbreviation of the chemical name
  • Brand name: given by the manufacturer and protected by copyright
• Drugs can be classified based on pharmacologic class or family, grouping them if they share similar characteristics

  • Example: Beta blockers like metoprolol, propranolol, atenolol block beta receptors
• Therapeutic class categorizes drugs based on their therapeutic use

  • Example: Anti-hypertensives include beta blockers and angiotensin receptor blockers (ARBs)
  • ARBs end with "sartan" and beta blockers end with "olol"
• Examples of therapeutic classes:

  • NSAIDs (Nonsteroidal Anti-Inflammatory Drugs)
  • Corticosteroids
  • Antibiotics
  • Diuretics
• Sources of drugs:

  • Plants: e.g., opium poppy for morphine
  • Animals: e.g., insulin from pigs
  • Minerals: e.g., magnesium sulfate
• Phytochemicals in plants responsible for pharmacologic use:

  • Alkaloids: active components with nitrogen in their structure
  • Glycosides: plant constituents with sugar in their structure
  • Example: Digoxin from foxglove plant is a glycoside used for heart failure
• Plant Constituents:

  • Gums have the ability to attract and hold water
  • Used as pharmaceutical excipients, e.g. as suspending or emulsifying agents for dosage forms
• Resins:

  • By-products from volatile oils processing
  • Can act as adhesives, just like gums
• Oils:

  • Two types: volatile and fixed oils
  • Volatile oils evaporate, while fixed oils leave a greasy residue
  • Examples: coconut oil (fixed), peppermint oil (volatile)
• Insulin:

  • Hormone obtained from animals
  • Enzymes like pancreatin and pepsin also obtained from animals
• Vaccines:

  • Obtained from microorganisms
  • Can be killed, modified, attenuated, or part of the microorganism
• Minerals:

  • Iron, iodine, Epsom salt
• Poisons:

  • Considered drugs but have harmful effects
  • According to Paracelsus, poisons have exclusively harmful effects
• Drugs Synthesized Inside the Body:

  • Example: Insulin
  • Synthesized by the body
• Toxins:

  • Also considered poisons but of biologic origin
  • Differentiated from inorganic poisons