General Pharmacology PDF

Prepared By; GENERAL PHARMACOLOGY Dr. Aya Abd EL-Salam Demonstrator of Pharmacology Department at Faculty of Veterinary Medicine Cairo University Pharmacology: It is a science dealing with drugs Derived from Greek word (pharmacon) Consist of detailed study on drug actions (ben...

Prepared By; GENERAL PHARMACOLOGY Dr. Aya Abd EL-Salam Demonstrator of Pharmacology Department at Faculty of Veterinary Medicine Cairo University Pharmacology: It is a science dealing with drugs Derived from Greek word (pharmacon) Consist of detailed study on drug actions (beneficial, harmful) on An.s ,tissues ,organs “drug” French word (Drogue) dry herb. defined as; any substance used for the purpose diagnosis, prevention and cure of a disease in man or animals.  1)Pharmacodynamics 2)Pharmacokinetics PD PK Study of actions , It is the science dealing with drug absorption Distribution Branches mechanism of drug action on living (ADME) biotransformation organisms. excretion of drugs. 3)Pharmacognosy 4)Pharmacy It is the science of drugs identification include It is the science concerned with Selection, description of standardization, sources , physical and chemical characters compounding, dispensing, identification, preservation of medical substances 5)Pharmacogenomics (PG): is the use of drugs for gene therapy 6)Clinical Pharmacology: the study of effects of drugs in the clinical situation including kinetics of drugs. 7)Pharmacotherapeutics; Chemotherapy; deals the therapeutic uses and effects of drugs 8)Toxicology: It is a branch of pharmacology that deals with the adverse effects of the drugs and poisonous substance include sources ,diagnosis ,treatment of xenobiotics. 9)Immunopharmacology: Effect of drugs on immune status of the body  Official books: standard books which give information on drugs, contain list of official drugs. Official drug : the drug which is listed in one of the official books.  1) Pharmacopeia : Official book contain : selected list of widely used drugs their physical, chemical proprieties tests for identity,purity,potency,medicinal preparations List of added (availability of more suitable substances) and deleted drugs (deleted due to their toxic effects). Such as : British Pharmacopeia (B.P) United Stated pharmacopeia (U.S.P)&Egyptian Pharmacopeia (E.P) International Pharmacopeia is published by WHO.  2) NATIONAL FORMULARY (N.F)  Published by American Pharmaceutical Association (APA)  selection of drugs in it is based on therapeutic effect rather than use of drug.  Include many formulae for commonly used pharmacy preparations like pills ,powders ,solutions. 3) British Pharmaceutical Codex (B.P.C)  From pharmaceutical society of great Britain.  Published by British Pharmaceutical Association (BPA)  It is the British counter-part of N.F  4) BRITISH VETERINARY CODEX (B.V.C)  From pharmaceutical society of Royal college  Published by British Veterinary Association (BVA)  Include medical substances and preparations used in veterinary practice. ***NEW AND NON-OFFICIAL REMEDIES (N.N.R)  It is annual publication of the council of pharmacy and chemistry of the American medical association  Contain descriptions of drugs which are marketed in an acceptable manner  Contain monographs on all individually available new drugs.  Sources of Drugs Organic Inorganic Atropine, Hormones Penicillin Aspirine, Mgso4, morphine, (Insulin ,Heparin vaccines Procaïne, NaHco3, ,Thyroid extract toxoid Sulphon- Znso4, strychnine ,Gonadotrophins) Amides, Liquid Antisera Hormone paraffin (anti tetanic sera.). Drug is a chemical substance that modify cell function  Sources of drugs 1- Organic sources: a) Plants: The active principles are extracted from plants and may be Present in leaves or seeds or roots (Atropine, morphine, strychnine). Used as it is in pure form or in preparation contain it. b) Animals: Hormones as Insulin, Heparin, Thyroid extract and Gonadotrophins. Or antisera (antitetanic sera). Animals tissues ,organs used to provide medications for replacement therapy.  Organic sources: c) Synthetics: as Hormones, Aspirin, Procaine ,cortisones ,ACTH ,adrenaline, Sulphonamides. d) Microorganisms: Bacteria and fungi consider an important source of antibacterial substances as penicillin's ,vaccines ,toxoid and bacitracin. The antigens injected into the body to induce formation of antibodies against bacterial ,viral diseases ,toxins ,toxoids ,vaccines.  Sources of drugs NaHco3 for gastric acidity 2- Inorganic sources: Mgso4 for constipation Liquid paraffin Znso4 for zinc deficiency Routes of drugs administration  Enteral Parenteral local Routes of drugs Oral Inhalation On skin & mm administration Sublingual Injection Implantation Rectal IV IM IP SC ID IA IS IC  I. Enteral route: any route deal with alimentary tract 1- Oral route  I. Enteral route: any route deal with alimentary tract 1- Oral route Advantages Disadvantages Safe and economic Not need Slow in action, irregular absorption sterilization ,dissolution Avoid disadvantages of Not suitable for: Irritant ,Unpalatable drugs parenteral routes. Unconscious animals An.s w vomiting, diarrhea ,inability to swallow. Convenient Drugs which destructed by Gastric acidity (penicillin, insulin, heparin) ‫مناسب ومريح‬ Hepatic enzymes (Nitroglycerin)  Routes of drugs administration 2- Sublingual:  Rapidly absorbed from oral mucosa with rapid action (Nitroglycerin- Isoprenaline) Used in heart attack  The drug is not exposed to gastric juice or hepatic metabolism before reaching to blood 3- Rectal:  Drugs are introduced into rectum in the form of suppositories or enema.  The drug escape from exposure to gut and hepatic inactivation.  This route is suitable when the animal is vomiting or the drug has highly offensive odor or taste  II. Parenteral route: all routes other than alimentary routes Advantages Disadvantages 1)used in un-conscious animals or 1. Less safe An.s suffered from vomiting, 2. More expensive diarrhea, inability to swallow 3. inconvenient 2)avoid destruction of drug by gastric juice. 3)Irritant drugs used in it. 4)Rapid action.  II. Parenteral route: all routes other than alimentary routes A- Inhalation: Drugs are given in form of Aerosol, Vapors, Spray (a) Isoprenaline, salbutamol ,epinephrine in bronchial Asthma (b) Halothane as general volatile anesthesia Advantages:- Disadvantages:- 1.Quick absorption 1.Local irritation may lead to 2.Rapid onset of action increase bronchial 3.Rapid attaining of effective drug secretion, suffocation. concentration 2.produce cardiac toxicity as 4.Effective in resp. diseases. drugs go directly to left side B- Injection: 1- Intravenous: IV Advantages:  Very rapid action and immediate onset of action (100% bioavailability) ,no absorption.  Useful for large volume of drugs,Unpalatable drugs, hypertonic solution , unconscious, vicious animals,irritant drugs or drugs with high acidity,useful in case of Emergency. Disadvantages:  Once drug is injected it can not be withdrawn.  Local irritation of B.V. may lead to venous thrombosis.  Slow injection must be done because sudden high blood concentration may cause cardiac arrest.  Transmission of viruses as Hepatitis C and AIDS  Leakage of drugs outside vein ; severe irritation 2- Intraperitoneal:  Useful for lab animals (rat & mice) when I/v injection is difficult.  Very rapid absorption occur due to large surface area. 3- Intramuscular:  Rapid in action and uniform drug absorption.  Mild irritant ,colloids, suspension can be given by deep IM  Volume of drug should not exceed 10 ml in large animals.  Painful and may cause abscesses. 4- Subcutaneous:  Slow absorption, prolonged action.  Absorption can be ENHANCED by adding hyaluronidase enzyme  Absorption can be SLOWED by adding adrenaline (local anesthetic procaine)  useful for non irritant Drugs only and must be aqueous solution (not suspension) 5- Intradermal:  Inject small doses between layers of skin  For vaccination and sensitivity tests 6-Intra-articular: in joints  For osteoarthritis and rheumatic arthritis 7- Intracardiac:  For cardiac resuscitation (recovery) in  Emergency 8- Intraspinal: subarachnoid : in lumbar region of spinal cord  For spinal anesthesia  III. Local application: topical method On Skin and M.M: (urethra ,nose ,vagina ,eye) as 1- Ointment 2- Lotion 3- Tincture 4- Powder 5- linament 6- Eye drops Implantation (implant)  is small pellets to be inserted under the skin s/c  as estrogen implants to be slowly absorbed  Progesterone implants for estrus synchronization.