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Introduction and general pharmacological principles Ján Mojžiš 1 Introduction What is pharmacology Historical background Pharmacological terminology Drug names 2 What is pharmacology the word Pharmacology comes from the Greek language: pharmakon (φάρμακον) meaning drug, and lego (λέγω) to tell (about) pharmacology is not identical with pharmacy 3 What is pharmacology (cont.) pharmacology deals with how drugs interact within biological systems to affect function pharmacy is the profession responsible for the preparation, dispensing, and appropriate use of medication, and provides services to achieve optimal therapeutic outcomes 4 History of Pharmacology Ancient Times A series of scattered facts exists that speak of the early history of humankind's efforts to harness the healing properties of natural compounds. However, what we know for certain is that ancient peoples made extensive use of plant, animal and mineral sources for this purpose. 5 History of Pharmacology The Ebers papyrus, written in Egypt in the 16th century B.C., lists the extensive pharmacopea of that civilization. Included in this are: beer, turpentine, myrrh, juniper berries, poppy, lead, salt etc. Also included were products derived from animals, including lizard's blood, swine teeth, goose grease, donkey hooves and the excreta from various animals. The effects of many of these drugs on patients of antiquity can only be imagined. 6 Ancient Greek medicine Hippocrates (460-370 B.C.) “Father” of western medicine (Born at Cos) Illness had a natural cause First to use observation of symptoms for clinical diagnosis; “observe patients” No dissection Used diet to counteract disease Four Humours - Illness was caused by natural factors inside the patient. Yellow bile, black bile, blood, and phlegm. 7 8 Ancient Roman medicine „Disease is a contraction or relaxation of pores which allowed fine atoms to pass sensation to parts of the body“ Galen (c. AD 129 - 201) Doctor to gladiators, later doctor of Marcus Aurelius Dissected animals, not humans Laid groundwork for physiological connections to anatomical design Diaphragm in respiration Clinical observation was key to diagnosis His texts were the basis of western medicine for 1500 years 9 History of Pharmacology From ancient China comes evidence of that culture's extensive efforts to heal through the use of natural products. The Pen Tsao, or Great Herbal, comprised forty volumes describing several thousands of prescriptions. 10 History of Pharmacology Interestingly, the eastern herb Artemisia annua L. (wormwood), used in China since antiquity to treat fevers, is the source of the modern drug artemisinin, which shows great promise as a modern anti-malarial compound. 11 Medicine in the Middle Ages Ibn Sina (Avicenna, 980-1037 AD) The cannon of medicine Medical standard text until the mid-1600’s Significant advances in pharmacology Compilation of Greek, Roman, & Persian medical knowledge; 12 History of Pharmacology Antiquity to the modern era The ancients considered disease a consequence of demonic possession, or the wrath of god. Thus, in ancient times, the treatment of illness with natural products was invariably accompanied by religious rituals deemed essential to the healing process. 13 History of Pharmacology With time, the thoughts returned to the appreciation that the natural products themselves held the power to cure. Although, traditional remedies still generally consisted of complex mixtures of distinct herbs and minerals, perhaps only one of which possessed any activity. Many poisonous mixtures were made. 14 History of Pharmacology For example, the purple foxglove, Digitalis purpurea, was one of twenty herbs used in a folk remedy to treat dropsy in 18th century England. From the leaves of this plant was isolated the cardiac glycoside digitalis, a drug still used today to treat heart failure. 15 History of Pharmacology Over time, as a more sophisticated view of illness evolved, an increasingly scientific approach to the isolation of drugs from natural products was taken. In the early 19th century, morphine was isolated from the opium poppy (Papaver somniferum) and the anti-malarial compound quinine from the bark of the cinchona tree (Cinchona officinalis). 16 History of Pharmacology In 1897, Felix Hoffman, a research chemist employed by the "Farbenfabrikin vorm. Freidr. Bayer and Co." synthesized acetylsalicylic acid. On February 1, 1899, Aspirin® was registered as a trademark. On March 6th of the same year, this drug was registered with the Imperial Patent Office in Berlin. Aspirin quickly become popular worldwide, and remains an important drug today. (Interestingly, it was not until 1971 that Sir John Vane discovered the mechanism of action of aspirin, a feat that earned him the 1981 Nobel Prize for Medicine.) 17 History of Pharmacology Paul Ehrlich described drug-receptor binding: “Corpora non agunt nisi fixate”. P. Ehrlich (1908) (“Agents do not act unless they are bound”) 18 History of Pharmacology The modern era Advances in the fields of chemistry and physiology, lead to the birth of modern pharmacology in the latter half of the 19th century. 19 History of Pharmacology Morphine: Sertirner in 1805 isolated morfin (the first pure drug) Salicylic acid: synthesized in 1860 by Kolbe and Lautemann Acetylsalicylic acid: synthesized in 1897 by F. Hoffman 1899 introduced into medicine : „aspirin’ Barbiturates: introduced into medicine in 1904 Salvarsan: Ehrlich in 1908 introduced into treatment of syphilis. Proposed the term chemotherapy Penicillin: discovered by Fleming in 1928 Chlorpromazine: in 1952 used in the treatment of schizophrenia Propranolol, Cimetidine developed by Black in 1960 Cyclooxygenase (COX): Vane in 1971 NO: Ignaro 1992 20 Pharmacological terminology Drug Pharmacokinetics Pharmacodynamics Pharmacotherapy Selectivity Toxicity 21 Pharmacological terminology (cont.) Therapeutic effect Indication Contraindication Undesired effects Side effects Toxic effects Idiosyncratic effects Allergy Anaphylaxis 22 What is drug ? Medicine - in the past was plant or animal substances a drug or a mixture of drugs combined with other substances to make it stable, palatable and useful for therapy Agent - a collective noun antihypertensive, anticancer agents. Compound - is a chemical used for pharmacological purpose, but not as a therapeutic agent 23 Drug names A single drug have a variety of names. 1. Chemical name 2. Generic name 3. Commercial or trade name 24 Chemical name Generic name Trade name 1,4-Dihydro-2,6-dimethyl-4-(2nitrophenyl)-3,5pyridinedicarboxylic acid dimethyl ester nifedipine 3,5-Diamino-N(aminoiminomethyl)-6chloropyrazinecarboxamide hydrochloride amiloride GUANAMPRAZINE, AMIPRAMIDIN, AMIPRAMIZIDE 7-chloro-3-methyl-2H-1,2,4benzothiadiazine-1,1-dioxide diazoxide HYPERSTAT, HYPERTONALUM, MUTABASE, PROGLYCEM, SRG 95213 7,8-didehydro-4,5-epoxy-17methylmorphinan-3,6-diol morphine MORPHIN 1%, MST CONTINUS, SEVREDOL, ORAMORPH, CYCLIMORPH ADALAT, CITILAT, NIFELAT 25 Drug names (contin.) Generic names It is the name which appears in official national Pharmacopeias (pure drugs). Often the only international differences betwen generic names is a difference in spelling. Generic name can vary : Norepinephrine is noradrenaline in Europe. Acetaminophene in USA is paracetamol in Europe. 26 Sources of drugs Plants and animals (most of drugs in ancient civilization came from plants or animal parts or fluids). From plants: alkaloids, glycosides and others. Extraction of hormones from animal endocrine glands Determination of chemical structure of active substance led synthetic chemists to produce many structural analogs During the last four decades introduction of new synthetized drugs (de novo). 27 Sources of drugs (cont.) Genetic engineering Insulin – E. coli Artemisinin is the most effective treatment for malaria it is made from plant found in China and Vietnam supplies of the plant are limited and it takes a lot of plant material to get enough of the drug to treat one patient researchers placed genes from the wormwood plant into a yeast organism and got it to produce large amounts of artemisinic acid - this would end the need for a lot of plants 28 Drug sources Plants Living organisms Chemical synthesis Elements 29 Drug Pharmacokinetics 1. Absorption 2. Distribution 3. Metabolism 3. Excretion Living organism Pharmacodynamics drug action how drugs act (mechanism of drug action) metabolism + excretion = elimination 30 Pharmacokinetics Is what the body does to the drug. The magnitud of the pharmacological effect of a drug depends on its concentration at the site of action. Absorption Distribution Metabolism Elimination 31 Pharmacodynamics Is what the drug does to the body. Interaction of drugs with cellular proteins, such as receptors or enzymes, to control changes in physiological function of particular organs. Drug-Receptor Interactions Binding Dose-Response Effect Signal Transduction Mechanism of action, Pathways 32 Actions of aspirin 1. Analgetic 2. Antipyretic 3. Antiinfammatory 4. Antiagregatory, 5. Anticancerogenic COX-2 Hypothesis (1990s) Normal Tissue Inflammation Site Arachidonic Acid + COX-1 Constitutive Cytokines Growth factors COX-2 Inducible COX-2 Inhibitors NSAIDs Physiolgical Prostaglandin Production Normal Functions Pathological Prostaglandin Production Inflammation, pain, fever 34 35 Recomended sources Lectures Practical excersises 36 lizard 37