Transcript drugs
– Pharmacon = drug or medicine (in Greek terms) ; Logos= science or learning • Definition: The science that deals with drugs, their nature, actions, mechanism of action, pharmacokinetics, therapeutic and other uses, preparations and administration. • Derived from the French word Drogue = Dry herb • The drug is any chemical substance when given to the organism alters body functions by interaction at the molecular level and is used in treatment (therapeutics), prevention, diagnosis of a disease or in prevention of pregnancy. – NB. Drugs will only modify existing cell function but do not create new ones. – What about gene therapy? • an approach to preventing and/or treating disease by replacing, removing or introducing genes or otherwise manipulating genetic material. – So cell functions may be increased, decreased by drugs. – What is your opinion about tea, coffee and smoking? Drugs or not? It is a drug which does not produce any pharmacological effect (not active) until it is chemically altered within the body. – The full chemical name e.g. Acetyl salicylic acid – Nonproprietary name= Official (in the pharmacoepia) or approved e.g., Aspirin U.S.P – Proprietary name =Manufacture (trade name) e.g., Aspocid, Rivo ( For Acetyl salicylic acid). – Generic name: Salicylates • NB Generic name refers to a class or a genus of compounds e.g. Sulphonamides, barbiturates, penicillins • However, generic is often misused as to mean nonproprietary • Drugs are obtained from one of the following sources: 1. 2. 3. 4. 5. 6. 7. Plant sources: Various parts of the plants may be used e.g., Leaves of belladonna for atropine. Animal sources: like insulin, heparin. Mineral sources: E.g., Mg sulphate and iodine. Microorganisms: Fungi and bacteria for antibiotics like penicillin Synthetic drugs: E.g., Sulphonamides, aspirin. Semi-synthetic: E.G. Heroin from morphine. (diacetylmorphine) Biotechnology: Using genetic engineering (gene therapy), human insulin (Recombinant DNA), and growth hormone. • Provides sound basis for selection of drugs in therapeutics. • Allows better understanding of drug toxicity. • Allows better understanding of drug interactions. Is the study of the kinetics of the drugs. It includes drug Absorption, Distribution, biotransformation (Metabolism), and Excretion (ADME) • = Effect of the body on the drug = What happened to drugs inside the body. Is the study of the biochemical, biophysical and physiological effects of the drugs as well as their mechanisms of action. • = Effect of the drug on the body= What drugs do to the organism. E.g. change in cardiac function, Blood pressure, etc • Proper selection and use of drugs for the prevention and treatment of diseases. is a consequence of a medical treatment of any kind, the results of which are judged to be desirable and beneficial. – We give the drug to produce the desired effect on certain tissue / organ or function in an appropriate dose. 4 : Describes the and of drugs. : A term used for harmful or seriously unpleasant effects of a drug occurring at doses used for therapeutic, prophylactic, diagnostic purposes and which call for reduction of dose, drug withdrawal and/or immediate treatment. : 1. Side effects: They are unavoidable part of the pharmacologic actions of the drug, for a specific indication, at therapeutic doses. 1. 2. 3. 4. E.G. Sedation with antihistamines Overdosage toxicity: These occur at high doses and their incidence increases as the dose level is increased Allergic reactions: Not dose-related, usually induced by prior contact with the drugs that act as antigens. Drug abuse: A special form of toxicity, is the use for non therapeutic purpose of drugs that act on CNS. This misuse of drug leads to dependence. E.g. Heroin, Morphine. Contd….. • A. : Are drug-induced diseases. – A drug prescribed for a disease causes another disease. • E.g. Drug-induced asthma, Peptic ulcer, Parkinsonism. • B. : (Teratos= Monster: genesis= Production) = Fetal abnormalities. It can be caused by some drugs when given early in pregnancy (3-10W) Intrauterine life. – E.G. Cytotoxic drugs, Tetracyclines, smoking. • 5. : For whom, the drug is forbidden to be prescribed because it will be harmful for them • 6. : They are pharmacological responses which cannot be explained by the action of one drug but are due to multiple drugs acting concurrently. – Drug interactions may be desired or undesired, beneficial or harmful Pharmacology text books. Medical journals. Pharmacopoeias. ?= Formulary • Is an official (published by authorized body) book containing a selected list of widely used drugs and medicinal preparations with descriptions of their physical properties and tests for their identity, purity, potency, safety. It also contains a description of the standard preparations of the drugs and their average doses (minimal effective dose, Maximum tolerated dose). Drugs are introduced according to their therapeutic usefulness. – I.E= Definition, potency, and purity of drugs are regulated by law. These data are published in books known as Pharmacopoeia • The majority of nations publish their own pharmacopoeia e.g., USP= United states Pharmacopoeia BP= British Pharmacopoeia EP= Egyptian Pharmacopoeia SAP= Saudi Arabia Pharmacopoeia • • • • Over-the counter drugs (OTC) Prescription drugs Controlled drugs e.g. Morphine & Cocaine Experimental drugs E.g. Anticancer drugs • An antibiotic; A chemical substance synthesized by living micro-organisms used to kill or stop growth of other microorganisms. E.g. Penicillin • A chemotherapeutic agent; A synthesized chemical substance used to stop the growth or kill microorganisms. E.g. Sulpha • Chemotherapy: is the use of chemical substances to treat infections caused by micro-organisms or kill cancer cells • Antibacterial: A chemical substance used to kill or stop growth of bacteria. It may be an antibiotic or a chemotherapeutic agent. • Antipyretic; A drug which lowers elevated body temperature • Analgesic: A drug which relieves pain or headache • Diuretics; Drugs which increase rate of water and solute production (volume of urine) • Sedatives / hypnotics; Drugs which sedate the patient and could induce hypnosis. • Antispasmodics; Drugs which relieve smooth muscle spasm (e.g. colic) • Antiemetics; Drugs which prevent and treat nausea and vomiting • Enteral – – – – Oral Sublingual (SL) Buccal Rectal • Parenteral – – – – – – – – – – Intradermal (ID) Subcutaneous (SC) Intramuscular (IM) Intravenous (IV) Intra-arterial (IA) Intrathecal: in anesthesia (IT) Intraperitoneal (IP) Intrapleural Intra-articular: in joints Inhalation • Topical – Skin, ear, eye, nose, vagina, respiratory tract.