Chemistry in Everyday life - Terminology used in Drug chemistry

• Drug - Any substance or mixture of substances that can be used to treat, cure, or prevent a disease or medical condition.
• Pharmacology - The study of the effects of drugs and how they interact with the body.
• Pharmaceuticals - Commercially available drugs.
• Active ingredient - The chemical component responsible for the therapeutic effect of a drug.
• Excipients - Inactive substances present in a drug formulation that help in drug stability, solubility, and overall effectiveness.

Chemistry in Everyday life - Classification of Drugs

• Drugs can be classified based on their:
  • Chemical structure
    • Example: Benzodiazepines, opioids, antibiotics.
  • Pharmacological action
    • Example: Analgesics, antihistamines, bronchodilators.
  • Biological target
    • Example: Enzyme inhibitors, receptor agonists, channel blockers.
  • Therapeutic use
    • Example: Anti-inflammatory drugs, antipsychotics, antihypertensives.

Chemistry in Everyday life - Drug Administration Routes

• Drugs can be administered through various routes such as:
  • Oral
    • Example: Tablets, capsules, syrups.
  • Intravenous
    • Example: Injections.
  • Topical
    • Example: Creams, ointments, patches.
  • Transdermal
    • Example: Patches.
  • Inhalation
    • Example: Inhalers, nebulizers.
  • Rectal
    • Example: Suppositories.

Chemistry in Everyday life - Drug Absorption and Distribution

• Absorption is the process by which a drug is taken into the bloodstream.

  • Factors affecting drug absorption:

    • Drug solubility
    • Molecular size
    • pH of the environment
• Distribution refers to the transport of a drug throughout the body.

  • Factors affecting drug distribution:

    • Blood flow
    • Protein binding
    • Lipid solubility
• Example equation for drug distribution: Drug concentration in blood = (Drug concentration in tissue) x (Tissue blood flow)

Chemistry in Everyday life - Drug Metabolism and Elimination

• Metabolism is the process by which drugs are metabolized or transformed in the body.
  • The liver is the primary site of drug metabolism.
  • Metabolism can result in the production of active or inactive metabolites.
• Elimination refers to the removal of drugs or their metabolites from the body.

  • Main routes of elimination: urine, feces, breath.

  • Factors affecting drug elimination:

    • Kidney function
    • Liver function
    • Drug half-life

Chemistry in Everyday life - Pharmacokinetics

• Pharmacokinetics involves the study of drug absorption, distribution, metabolism, and elimination.
• It helps determine the dosage and dosing schedule for a drug.
• Pharmacokinetic parameters include:

  • Bioavailability: The fraction of the administered dose that reaches the systemic circulation.

  • Half-life: The time it takes for half of the drug concentration to be eliminated from the body.

  • Clearance: The rate at which a drug is removed from the body.

  • Volume of distribution: The hypothetical volume needed to contain the total amount of a drug in the body at the same concentration as in the plasma.

Chemistry in Everyday life - Drug Interactions

• Drug interactions occur when the presence of one drug affects the pharmacological action of another drug.
• Types of drug interactions:
  • Pharmacokinetic interactions: involving drug absorption, distribution, metabolism, or elimination.
  • Pharmacodynamic interactions: involving the direct effect of one drug on the target of another drug.
• Examples of drug interactions:

  • Drug A increasing the effects of Drug B.

  • Drugs A and B interfering with each other’s metabolism.

Chemistry in Everyday life - Drug Resistance

• Drug resistance occurs when a drug becomes less effective in treating a disease or condition.
• Mechanisms of drug resistance:

  • Mutation: Changes in the genetic material of the target organism, making it less susceptible to the drug.

  • Efflux pumps: Proteins that actively pump the drug out of the target organism.

  • Enzyme inactivation: Production of enzymes that render the drug inactive.

  • Decreased drug uptake: Reduced entry of the drug into the target organism.

• Drug receptor: The specific protein target to which a drug binds in order to produce its pharmacological effects.
• Agonist: A drug that binds to a receptor and activates it, producing a biological response.
• Antagonist: A drug that binds to a receptor but does not activate it, blocking the binding of other substances to the receptor.
• Partial agonist: A drug that binds to a receptor and produces a partial or intermediate biological response compared to a full agonist.
• Enzyme inhibitor: A drug that inhibits the activity of an enzyme, thereby blocking or slowing down a biochemical process in the body.

• Drug formulation: The process of combining the active ingredient(s) with excipients to create a drug product.
• Immediate-release formulation: A drug formulation that releases the active ingredient(s) quickly after administration.
• Extended-release formulation: A drug formulation that releases the active ingredient(s) slowly and continuously over an extended period of time.
• Enteric-coated formulation: A drug formulation in which the tablets or capsules are coated with a substance that prevents dissolution in the stomach, allowing for targeted release in the intestines.
• Sustained-release formulation: A drug formulation that releases the active ingredient(s) gradually over an extended period of time, maintaining therapeutic levels in the body.

• Prodrug: An inactive or less active compound that is converted into an active drug when it is metabolized in the body.
• Drug delivery systems: Various techniques and technologies used to deliver drugs to specific target sites in the body, increasing their effectiveness and reducing side effects.
• Nanotechnology in drug delivery: The use of nanoscale materials and devices to improve drug delivery, allowing for targeted delivery, controlled release, and enhanced drug stability.
• Liposomes: Artificial vesicles made of lipids that can encapsulate drugs and improve their solubility and targeted delivery.
• Polymer-based drug delivery systems: Polymer materials that can encapsulate drugs and release them at a controlled rate, enhancing drug stability and targeting specific tissues or cells.

• Pharmacogenomics: The study of how an individual’s genetic makeup influences their response to drugs.
• Genetic polymorphism: Natural variations in a person’s DNA sequence that can affect drug metabolism, effectiveness, and side effects.
• Cytochrome P450 enzymes: A family of enzymes involved in drug metabolism, with genetic polymorphisms that can impact drug response.
• Therapeutic drug monitoring: Measuring drug concentrations in the blood to optimize drug dosing and prevent toxicity or ineffective treatment.
• Personalized medicine: Tailoring drug treatments to an individual’s genetic characteristics and other factors to maximize effectiveness and minimize side effects.

• Drug safety: Ensuring that drugs are effective and minimize harm to patients.
• Preclinical testing: Testing the safety and efficacy of drugs in laboratory and animal models before human trials.
• Clinical trials: Controlled studies in humans to evaluate the safety and efficacy of a drug.
• Phase I: Small-scale studies on healthy volunteers to evaluate drug safety, dosage, and side effects.
• Phase II: Studies on a larger group of patients to evaluate drug effectiveness and further assess safety.

• Phase III: Large-scale studies involving a larger patient population to confirm the drug’s effectiveness, monitor side effects in a diverse population, and compare it to existing treatments.
• Phase IV: Post-marketing surveillance studies conducted after a drug has been approved to monitor its long-term safety and effectiveness in real-world conditions.
• Adverse drug reactions: Unexpected or harmful reactions to a drug, which can range from mild to severe and require careful monitoring and reporting.
• Black box warning: The strongest warning label that the FDA can require for a specific drug, indicating serious or life-threatening risks.

• Drug patents: Exclusive rights granted to the inventors of a drug to prevent others from making, using, or selling the drug for a specified period.
• Generic drugs: Medications that contain the same active ingredient(s) as the brand-name drug and are approved by regulatory authorities after the patent for the brand-name drug has expired.
• Bioequivalence: The demonstration that two drug products (brand-name and generic) are pharmaceutically equivalent and produce the same pharmacological and therapeutic effects.

• Over-the-counter drugs: Medications that can be purchased without a prescription and are deemed safe and effective for self-medication when used as directed.
• Prescription drugs: Medications that require a prescription from a healthcare professional, usually due to potential risks, complexity, or need for monitoring.
• Orphan drugs: Drugs developed to treat rare diseases or conditions that affect a small number of people.

• Drug pricing: The process of determining the cost of drugs, including factors such as research and development costs, production costs, marketing expenses, and profit margins.
• Pharmaceutical industry: The sector of the economy that develops, manufactures, and markets drugs for human use.
• Drug regulation: Government oversight and control of the manufacturing, marketing, and use of drugs to ensure safety, effectiveness, and quality.

• Drug recalls: The removal or correction of drugs that pose a risk to public health, based on evidence of quality issues, safety concerns, or regulatory non-compliance.
• Counterfeit drugs: Fake or unauthorized drugs that mimic the appearance of genuine drugs but may contain incorrect or harmful ingredients, putting patients’ health at risk.
• Pharmacy practice: The profession of pharmacy, which includes dispensing medications, providing patient counseling, managing drug therapy, and promoting public health and wellness.

• Prodrug: An inactive or less active compound that is converted into an active drug when it is metabolized in the body.
  • Example: Codeine is a prodrug that is converted to morphine in the liver.
• Drug delivery systems: Various techniques and technologies used to deliver drugs to specific target sites in the body, increasing their effectiveness and reducing side effects.
  • Example: Liposomes, polymer-based drug delivery systems.
• Nanotechnology in drug delivery: The use of nanoscale materials and devices to improve drug delivery, allowing for targeted delivery, controlled release, and enhanced drug stability.
  • Example: Lipid nanoparticles, dendrimers.

• Liposomes: Artificial vesicles made of lipids that can encapsulate drugs and improve their solubility and targeted delivery.
  • Example: Liposomal amphotericin B, used to treat fungal infections.
• Polymer-based drug delivery systems: Polymer materials that can encapsulate drugs and release them at a controlled rate, enhancing drug stability and targeting specific tissues or cells.
  • Example: Polymeric micelles, hydrogels.
• Targeted drug delivery: Delivering drugs specifically to the site of action, reducing systemic side effects.
  • Example: Antibody-drug conjugates, nanoparticles targeted with ligands.

• Pharmacogenomics: The study of how an individual’s genetic makeup influences their response to drugs.
  • Example: Testing for genetic variants in the CYP2D6 gene to determine the optimal dose of a drug metabolized by this enzyme.
• Genetic polymorphism: Natural variations in a person’s DNA sequence that can affect drug metabolism, effectiveness, and side effects.
  • Example: Poor metabolizers of CYP2C19 have a higher risk of adverse effects when taking certain drugs, such as clopidogrel.

• Cytochrome P450 enzymes: A family of enzymes involved in drug metabolism, with genetic polymorphisms that can impact drug response.
  • Example: CYP3A4, the most abundant P450 enzyme in the liver, metabolizes a wide range of drugs, including benzodiazepines and statins.
• Therapeutic drug monitoring: Measuring drug concentrations in the blood to optimize drug dosing and prevent toxicity or ineffective treatment.
  • Example: Monitoring the blood levels of digoxin to ensure it is within the therapeutic range for treating heart failure.

• Personalized medicine: Tailoring drug treatments to an individual’s genetic characteristics and other factors to maximize effectiveness and minimize side effects.
  • Example: Using genetic testing to identify patients who are likely to benefit from certain targeted therapies, such as trastuzumab for HER2-positive breast cancer.
• Pharmacovigilance: The monitoring, detection, assessment, and prevention of adverse effects of drugs to ensure their safe and effective use.
  • Example: National and international databases for reporting and analyzing adverse drug reactions.

• Drug safety: Ensuring that drugs are effective and minimize harm to patients.
  • Example: Preclinical testing and clinical trials to evaluate drug safety and efficacy before approval.
• Preclinical testing: Testing the safety and efficacy of drugs in laboratory and animal models before human trials.
  • Example: In vitro cell culture studies, animal toxicity studies.

• Clinical trials: Controlled studies in humans to evaluate the safety and efficacy of a drug.
  • Example: Phase I, Phase II, Phase III, and Phase IV trials.
• Phase I: Small-scale studies on healthy volunteers to evaluate drug safety, dosage, and side effects.
  • Example: Determining the maximum tolerated dose of a new cancer drug.

• Phase II: Studies on a larger group of patients to evaluate drug effectiveness and further assess safety.
  • Example: Testing the efficacy of a new drug for treating a specific disease or condition.
• Phase III: Large-scale studies involving a larger patient population to confirm the drug’s effectiveness, monitor side effects in a diverse population, and compare it to existing treatments.
  • Example: Randomized controlled trials with thousands of participants.

• Phase IV: Post-marketing surveillance studies conducted after a drug has been approved to monitor its long-term safety and effectiveness in real-world conditions.
  • Example: Assessing the long-term safety of a drug after it has been on the market for several years.
• Adverse drug reactions: Unexpected or harmful reactions to a drug, which can range from mild to severe and require careful monitoring and reporting.
  • Example: Allergic reactions, drug-induced liver injury.

• Black box warning: The strongest warning label that the FDA can require for a specific drug, indicating serious or life-threatening risks.
  • Example: Adequate warnings about the potential risk of suicidal thoughts and behavior in certain antidepressant medications.
• Off-label drug use: The use of a drug for a purpose or in a population not specifically approved by regulatory authorities.
  • Example: Prescribing an antihistamine for its sedative effects, even if it’s not indicated for that purpose.