1 Pharmacology an overview.pdf

GENERAL PHARMACOLOGY(1) BY DR ABDEL BASET TAHER PROFESSOR OF PHARMACOLOGY & THERAPEUTICS and PEDIATRIC CONSULTANT 2019 MBBS-Y1, SEM2 PHARMACOLOGY AN OVERVIEW Learning Objectives 1. Definition of terms: pharmacology,...

GENERAL PHARMACOLOGY(1) BY DR ABDEL BASET TAHER PROFESSOR OF PHARMACOLOGY & THERAPEUTICS and PEDIATRIC CONSULTANT 2019 MBBS-Y1, SEM2 PHARMACOLOGY AN OVERVIEW Learning Objectives 1. Definition of terms: pharmacology, drugs, toxicology. 2. Illustrate naming of drugs. 3. Classify drugs into POM, OTC, Orphan drug. 4. Describe aspects of pharmacology. 5. Provide knowledge on history of pharmacology and sources of drugs.  Definition of pharmacology : ~ Studying the action of drugs on living cells and the mechanism of action ~ ~ (How to treat diseases OR The art of treatment of diseases Drugs: chemical agents that affect living processes and used in treatment, prevention or diagnosis of disease. Prof. Dr AbDel Baset Taher 4 Drug names: Many drugs have a variety of names. This may cause confusion to the patient, physician, and nurse, so care must be taken in obtaining the exact name and spelling of a particular drug..Chemical name: Shows the chemical constitution of the drug..Generic name (non proprietary name): Before a drug becomes official, it's given a generic name or common name. A generic name is simpler than the chemical name. It may be used in any country and by any manufacturer. The first letter is not capitalized. PROF. DR ABDEL BASET TAHER 5.Trade name or proprietary name: It's followed by the symbol R , this indicates that the name is registered and that its use is restricted to the owner of the drug who is usually the Manufactures. The trade names are made easier to pronounce, spell and remember. The first letter is capitalized. Example (Ampicillin antibiotic):.Chemical name: 4-thia-1-azabicyyclo [3.2.0] heptane-2-carboylic acid, 6…………..Generic name: ampicillin..Trade name: principer, Ampicid. PROF. DR ABDEL BASET TAHER 6  Drug classification: 1. Prescription only medications (POM): restricted for sale by prescription only 2. Over the counter drugs (OTC): used by public without a prescription e.g. analgesic antipyretic 3. Orphan drugs: Drugs used to treat rare diseases e.g. recombinant antihemophilic factor PROF. DR ABDEL BASET TAHER 7  N.B. Toxicology is a branch of pharmacology that deals with undesirable effects of chemicals on living systems. Main aspects of pharmacology: 1- Pharmacokinetics: what the body does to the drug? OR The study of the kinetics of the drug which include Absorption, Distribution, Metabolism and Excretion (ADME) 2- Pharmacodynamics: what the drug does to the body? OR The study of the pharmacological actions of drugs and their mechanisms of action. 3- Pharmacotherapeutics: proper selection and use of drugs for prevention and treatment of disease. PROF. DR ABDEL BASET TAHER 8  HISTORY * Prehistoric people recognized the beneficial or toxic effects of many plant and animal materials. The earliest written record from China and from Egypt list remedies of many types, a few still recognized as useful drugs. * 2500 years preceding the modern era, there were sporadic attempts to introduce rational methods into medicine, but none were successful owing to the thought that tend to explain biology and disease without the need for experimentation and observation. PROF. DR ABDEL BASET TAHER 9  Around the end of 17th century, reliance on observation and experimentation develops. Physicians in Great Britain and elsewhere in Europe began to apply them to the effects of traditional drugs used in their practice. Thus materia medica (the science of drug preparation and use of drugs) began to develop as the precursor to pharmacology. * In the late 18th century Francois Magendi and Claude Bernard began to develop experimental animal physiology and pharmacology. PROF. DR ABDEL BASET TAHER 10  In late 18th, 19th, 20th centuries, advances in chemistry and physiology laid the foundation for understanding how drugs work. * 50 years ago, information accumulated about drug action, receptors. Many new drug groups and new members of old groups have been introduced; the last 3 decades have seen rapid growth of information and understanding molecular basis for drug action. 11  Sources of drugs: 1- Plant sources e.g. leaves of belladonna for atropine, bark of cinchona for quinine and quinidine. 2- Animal sources e.g. insulin from pancreas of animals, heparin from liver or lung tissues. 3- Mineral sources e.g. Mg sulphate, I131, P Prof. Dr Abddel Baset Taher 12  4- Microorganisms e.g. fungi and bacteria are sources of antibiotics as penicillin. 5- Synthetic drugs e.g. barbiturate, salicylate. 6- Biotechnology e.g. human insulin, growth hormone have been produced by genetic engineering. Prof. Dr Abel Baset Taher 13 PHARMACOLOGY & GENETICS It has been known for centuries that certain diseases are inherited, and we now understand that individuals with such diseases have a heritable abnormality in their DNA. During the last 10 years, the genomes of humans, mice, and many other organisms have been decoded in considerable detail. This has opened the door to a remarkable range of new approaches to research and treatment. Prof. Dr Abel Baset Taher 14  It is now possible in the case of some inherited diseases to define exactly which DNA base pairs are anomalous and in which chromosome they appear. In a small number of animal models of such diseases, it has been possible to correct the abnormality by gene therapy, ie, insertion of an appropriate "healthy" gene into somatic cells. Human somatic cell gene therapy has been attempted, but the technical difficulties are great. Prof. Dr AbDel Baset Taher 15  Some patients respond to certain drugs with greater than usual sensitivity to standard doses. It is now clear that such increased sensitivity is often due to a very small genetic modification that results in decreased activity of a particular enzyme responsible for eliminating that drug. Pharmacogenomics (or pharmacogenetics) is the study of the genetic variations that cause differences in drug response among individuals or populations. Future clinicians may screen every patient for a variety of such differences before prescribing a drug. Prof. Dr Abel Baset Taher 16 Prof. Dr Abel Baset Taher 17