Lecture 1 - Introduction To Pharmacology PDF

Dr. Wesam Abdel-Razaq PHBS - 301 Introduction Introduction to Pharmacology to Pharmacology Dr. WesamDr. Tariq Alqahtani Abdel-Razaq / Dr. Mai Al Ajaji Dr. Rawan Al Nafisah ...

Dr. Wesam Abdel-Razaq PHBS - 301 Introduction Introduction to Pharmacology to Pharmacology Dr. WesamDr. Tariq Alqahtani Abdel-Razaq / Dr. Mai Al Ajaji Dr. Rawan Al Nafisah  2 LECTURE LEARNING OUTCOMES At the end of the lecture, the students should be able to: 1. Understand the basic foundation of pharmacological sciences. 2. Illustrate the basic principles behind the use of drugs in the diagnosis, prevention and treatment of diseases including their names, sources, classification, doses and routes of administration. 3. Discuss the factors that influence therapeutic indication, dosage, efficacy, response and compliance to drugs. 4. Describe available sources of drug information. PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  3 A Brief Historical Overview of Pharmacology Science of pharmacology may date back to circa 10,000–7,000 B.C In print, the word "pharmacology" was first used in the seventeenth century. Bernhard Naunyn Rudolf Buchheim Johann Ernst Oswald PROBLEM: "I have a headache" Schmiedeberg Philippu A, Seifert R. History of pharmacology: 1-the Department of Pharmacology of the University of Tartu (Dorpat): genealogy and biographies. Naunyn Schmiedebergs Arch Pharmacol. 2023 Jan;396(1):5-17. doi: 10.1007/s00210-022-02328-x. Epub 2022 Nov 21. PMID: 36413339; PMCID: PMC9789002. Barrett JE, Page C, Michel MC. Perspectives of pharmacology over the past 100 years. Concepts and Principles of Pharmacology: 100 Years of the Handbook of Experimental Pharmacology. 2019:3-16. Parascandola J. Reflections on the history of pharmacology. Trends in Pharmacological sciences. 1982 Jan 1;3:93-4. PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  4 Pharmacology Definition  The word Pharmacology is originally derived from the Greek word: pharmakon, which means drug and logia, meaning knowledge of. Pharmacology can be defined as “the study of the effects of drugs on the function of living organisms”. Pharmacology deals with the actions, clinical uses, mechanism of action, side/adverse effects and the fate of drugs in the body. PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  5 Medical pharmacology and Toxicology Medical pharmacology is the study of drugs used for the diagnosis, prevention, and treatment of disease. Toxicology is the study of the undesirable effects of chemical agents on living systems. It is usually considered an area of pharmacology. The central goal of the pharmacology courses series is two-fold, thus: ◦ First, to provide students with a solid grounding in the basic concepts of Pharmacology, involving the following: pharmacokinetics, pharmacodynamics, drug metabolism and drug-drug interactions. ◦ Second, to equip the students with a comprehensive understanding of the mechanisms of actions, interactions, and effects of various drugs on living organisms and uses of the major classes of clinically important drugs currently utilised in clinical practice. PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  6 Principles of Pharmacology Principle 1: Drugs do not create functions but modify existing functions within the body. Principle 2: No drug has a single action. Principle 3: Drug action is determined by how the drug interacts with the body. This can happen in several different ways: ◦ Drugs can chemically alter body fluids, e.g., antacids (acid-base equilibrium). ◦ Drugs can physically alter cell membranes, e.g., anaesthetics, solvents (disruption of the molecular order of membranes). ◦ Drugs can act through specific receptors (proteins) which mediate intracellular processes. PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  7 Properties of Ideal Drug PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  8 PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  9 Additional Properties of an Ideal Drug 1. Reversible action ◦ Effects be reversible, i.e., removal/subside within a specific time (1/2 life is short but potent during that time) ◦ Examples: General Anaesthetic; Contraceptives 2. Predictability ◦ Know how patient will respond 3. Ease of Administration ◦ Number of doses should be low and easy to administer ◦ (1) increase compliance & (2) decrease errors ◦ Diabetic patient: multiple daily injection of insulin ◦ Intravenous infusion PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  10 Additional Properties of an Ideal Drug 4. Freedom from drug interactions ◦ Should not increase or decrease action of other drugs or have adverse combined effects ◦ Respiratory depression caused by diazepam (valium), which is normally minimal, can greatly be intensified by alcohol. ◦ Antibacterial effects of tetracycline can be greatly reduced by taking iron or calcium supplements 5. Low Cost ◦ Easy to afford (especially with chronic illness) ◦ Growth hormone (somatrem) costs between $10,000 and $20,000 ◦ Lifelong medication: hypertension, arthritis, diabetes PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  11 Additional Properties of an Ideal Drug 6. Chemical Stability ◦ No loss of effectiveness with storage 7. Possession of a simple generic name ◦ Easy to remember and pronounce ◦ Example:  Viagra (sildenafil)  Panadol (Paracetamol) Tylenol (acetaminophen) PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  12 Because No Drug is Ideal … No drug is safe All drugs produce side effects Drug responses may be difficult to predict Drugs may be expensive Drugs may be hard to administer All members of health-care team must exercise care to promote therapeutic effects and minimise drug induced harm PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  13 PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  14 The Therapeutic Objective When you use or handle a drug, remember that: ◦ All substances are poisons (toxic). ◦ The right dose differentiates a poison and a remedy. The objective of drug therapy is to provide the maximum benefit with minimum harm. PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  Factors That Determine Intensity of Drug 15 Response 1-Administration – dosage size and route As a result of errors in administration routes and dosage and at wrong times there are many discrepancies in what a patient gets and could cause more harm than good. ◦ Errors could be made by physicians, pharmacists or nurses. ◦ Should give patients complete instructions about their medication and how to take it. PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  16 Factors That Determine Intensity of Drug Response 2. Pharmacokinetic processes (ADME) Determines how much of an administered dose gets to its sites of action (Absorption, Distribution, Metabolism, Excretion) 3. Pharmacodynamics Once a drug has reached its site of action, pharmacodynamic processes determine the type and intensity of response(s). ◦ Drug must first bind to its specific target site at (RECEPTOR) ◦ Followed by a sequence of events that result in response(s) PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  17 Factors That Determine Intensity of Drug Response 4.Sources of individual variation Each patient is unique in ability to respond and to how they each respond, ◦Age – very important factor ◦Sex – due to hormonal differences ◦Weight – less effective and longer lasting in obese individuals (storage in fat) ◦Kidney & liver functions – elimination of drug ◦Genetic variables – tolerance, allergy PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  18 Factors That Determine Intensity of Drug Response PHRB 301 Lecture 1 - Introduction to Pharmacology Dr. Tariq Alqahtani/Dr. Rawan Alnafisah  19 Great Discoveries and Future Directions in Pharmacology Mitra A, Barua A, Huang L, Ganguly S, Feng Q, He B. From bench to bedside: the history and progress of CAR T cell therapy. Frontiers in Immunology. 2023 May 15;14:1188049. Rubin RP. A brief history of great discoveries in van der Lee M, Swen JJ. Artificial intelligence in pharmacology research pharmacology: in celebration of the centennial and practice. Clinical and Translational Science. 2023 Jan;16(1):31-6. anniversary of the founding of the American PHRB 301 Society of Pharmacology and Experimental Therapeutics. Pharmacological reviews. 2007 Lecture 1 - Introduction to Pharmacology Dec 1;59(4):289-359. Dr. Tariq Alqahtani/Dr. Rawan Alnafisah