Introduction to General Pharmacology PDF

Introduction to Pharmacology Dr/ Samar Mahmoud Imbaby Lecturer of Clinical Pharmacology Faculty of Medicine, Suez Canal University  Lecture Objectives Differentiate among the following terms: Define the term of ❑Pharm...

Introduction to Pharmacology Dr/ Samar Mahmoud Imbaby Lecturer of Clinical Pharmacology Faculty of Medicine, Suez Canal University  Lecture Objectives Differentiate among the following terms: Define the term of ❑Pharmacokinetics, pharmacology ❑Pharmacodynamics, ❑Pharmacotherapeutics, ❑Pharmacy, Drugs: ❑pharmacognosy, Define the term of a drug. ❑Clinical Pharmacology, Enumerate the sources of ❑Toxicology, drugs. ❑Posology, ❑Pharmacogenomics, Discuss drugs Nomenclature. ❑Pharmacoepidemeology.  Introduction Living Organism Physiological Physiology functions DRUG Biochemistry Chemical Reactions  Drug A drug : any chemical agent which affects the physiologic processes of a living organism. According to definition of WHO, A drug is any substance or product that is used or intended to be used to modify or explore physiological systems or pathological states for the benefit of recipient.  Components of a Drug Profile Source Mechanism of Action Names Indications / Uses Classification With doses (with prototype) Contraindications Routes of Administration Side Effects Pharmacokinetics Drug Interactions How Supplied  Pharmacology Pharmacology: is the science that deals with the fate and actions of drugs, their nature, Pharmacokinetics, Pharmacodynamics, therapeutic uses, preparations and administrations. The word pharmacology is derived from the Greek words pharmacon (drug or poison) and logos (science).  Objects of Pharmacology 1. Pharmacodynamics -how the drugs act on the body? 2. Pharmacokinetics - how the body act on the drugs? 3. Drug Indications and Application 4. Drug Interactions 5. Unwanted (adverse) effects Drug categories Prescription drugs Are used under only medical supervision and dispensed by an order of medical practitioner only OTC drugs Can be sold over the counter without prescription  Over-The-Counter Drugs (OTC) Drugs that can be purchased without prescription OTC account for >60% of all doses administered Do consumers have the ability & knowledge to self prescribe? – In 1999 the FDA passed a regulation that requires OTC drugs to have informative and easy to understand labels – Know sources of drug information to pass on to patients Branches (Principles) of Pharmacology  Pharmaceutics Pharmaceutics: the study of how various drug forms influence pharmacokinetic and pharmacodynamic activities  Pharmacokinetics Pharmacokinetics: This branch deals with the study of “What the body does to the drug. This refers to the movement of drug in the body and alteration of drug by the body. A.D.M.E.: A---------Absorption D---------Distribution M---------Metabolism E----------Excretion ( kinesis → movement )  Pharmacodynamics Pharmacodynamics: This branch deals with the study of WHAT THE DRUG DO TO THE BODY? The action of the drug on the body: (mechanism of action and biological actions) (dynamis → power / activity ) Pharmacology is the base of Pharmacotherapeutics (the treatment of diseases with drugs). It overlaps extensively with pharmacy - the science of drug production.  Pharmacotherapeutics It deals with the use of drugs and the clinical indications for drugs to prevent and treat diseases and ameliorate the symptoms. Clinical application of pharmacodynamics and pharmacokinetics information to cure a disease. (therapeutic → treatment)  PHARMACY It is the science of compounding and dispensing drugs and preparing suitable dosage forms.  PHARMACOGNOSY PHARMACOGNOSY: It deals with source, identification and physical and chemical properties characteristics of drugs. The study of natural (plant and animal) drug sources. Sources of Drugs Plant sources – Morphine Animal sources – Insulin, heparin Minerals – ferrous sulfate (iron salt). Micro – organisms – Bacteria and fungi – Penicillin Synthetic – sulfa drugs Genetic Engineering – Human insulin  Clinical Pharmacology It deals with the comparative clinical evaluations of NEW drug for developing its therapeutic efficacy and safety. pharmacodynamic and pharmacokinetic investigations, the efficacy and safety of drugs  TOXICOLOGY It deals with the adverse effects of drugs and the toxic effects due to poisoning by drugs.  POSOLOGY This branch of Pharmacology deals with doses of drugs.  Pharmacogenomics It deals with the genetic make up (Genome) of individual to choose drug therapy.  Pharmacoepidemeology It deals with the study of use and effects of the drug in large population to establish Risk: Benefit ratio of the drug. 1. Which of the following is INCORRECT? a. Pharmacodynamics deals with the action of the drug on the body. b. Pharmacognosy deals with the study of natural drug sources. c. Over-The-Counter Drugs are drugs purchased without prescription. d. Pharmacogenomics deals with doses of drugs.  Drug Nomenclature A drug has three categories of names. Chemical name Describes the drug’s chemical composition and molecular structure usually too complex for people to remember Generic name Name given by the United States Adopted Name Council Only one generic name/compound (nonproprietary name) Trade name (proprietary name) Name by which drug is marketed, must be approved by FDA  Drug Nomenclature Chemical name (+/-)-2-(p-isobutylphenyl) propionic acid Generic name ibuprofen Trade name Motrin®, Advil® 2. Drug name describes the drug’s chemical composition and molecular structure is……….. a. Generic name b. Trade name c. Chemical name d. Proprietary name  Chemical name: 2-(diethylamino)- 2’,6’- acetooxylid mono-hydrochloride mono-hydrate Generic name: Ampicillin One drug may have Multiple trade name, e.g., Ampicillin: Penbritin® Omnipen® Standacillin® (GSK) (Wyeth) (Novartis / Sandoz)  A single drug can have multiple Trade Names – Acetaminophen has >30 Trade Names – Recalling Generic name may be easier than trying to remember all the different Trade Names of a drug – More accurate communication if use Generic name – Less confusing for patient to see only one Generic name on label rather than different Trade Names (double dosing?) Try to discourage the use of Trade Names and promote the use of Generic Names for patients ▪ Enteral 1. oral 2. sublingual ▪ Parenteral 1. IV 2. IM 4. Sc 5. others: rectal, inhalation, intranasal, topical, transdermal, intrathecal  Application of Pharmacology in Practice “Five Rights of Drug Administration” – Use the RIGHT drug – Give to the RIGHT patient – Give the RIGHT dose – Give by the RIGHT route – Give at the RIGHT time Must also be ready to respond to interaction between drug and patient (i.e., must be aware of DRUG REACTIONS and SIDE EFFECTS)  Drug Legislation Federal Food, Drug , and Cosmetic Act Controlled Substance Act Schedule I Schedule II Schedule III Schedule IV Schedule V Schedule F  Drug Legislation – 1st Law to regulate drugs passed in 1906 – Food, Drug and Cosmetic Act, passed in 1938 Regulated drug safety All drugs must be tested for safety and must be OK’ed by FDA for marketing – 1970 passed the “Controlled Substances Act”: specifically for drugs in which there could be potential for abuse 1- Schedule I drugs: no accepted medical use in US (heroine, LSD,…) 2- Schedule II-V drugs: have accepted medical use but are susceptible to abuse. Potential for abuse becomes LESS as you go from level II to level V Food and drug administration classification of Drugs in pregnancy FDA Categories : teratogenic risk of drugs https://wikem.org/wiki/Drug_pregnancy_cate gories  FDA Pregnancy Categories A Controlled studies in humans & animals→ NO RISK e.g. Paracetamol, folic acid, thyroxine, insulin, Vitamins (B, C, D, E), B Human studies→ NO RISK, Animal studies→ +ve results e.g. Metronidazole, Penicillin, Cephalosporins, NSAIDs in 1st, 2nd trimester (NO EVIDENCE OF RISK) C NO Human data+ Animal studies positive RISK CANNOT RULED OUT. Most drugs D Human studies→ evidence of risk, benefit > risk EVIDENCE OF RISK e.g. antiepileptics, Progesterone, NSAIDs in 3rd X Human studies→ risk, Risk > benefit. CONTRAINDICATED. e.g. all previously mentioned teratogens such as Androgens, estrogens, Grisofulvin.  Drug action Desired action Side effects/adverse effects Idiosyncratic reaction Allergic reactions anaphylactic reaction Carcinogenicity Teratogen  List of Referencs 1- Essential Books (Text Books) Lippincott's pharmacology Rang and Dale`s (clinical pharmacology) Katzung's Basic & Clinical Pharmacology 2- Periodicals, Web Sites, etc… www.Pubmed.com www.sciencedirect.com American journal of pharmacology and experimental therapeutics European journal of pharmacology  Samar Imbaby, PhD lecturer of Clinical Pharmacology, Faculty of Medicine, Suez Canal University E-mail: [email protected] ORCID ID: https://orcid.org/0000-0002-2130-2724 Web of Science Researcher ID: AAV-4415-2021 Youtube: https://www.youtube.com/channel/uc1gdy w56pfgdjeam9a9fjia/videos