Introduction to Pharmacology PDF

INTRODUCTION TO PHARMACOLOGY Dr. Salma Naqvi Asst. Prof., Pharmacology GMU, Ajman Learning objectives: Definition and introduction to pharmacological terms like: Pharmacology Drugs and receptors Pharmacokinetics Pharmacody...

INTRODUCTION TO PHARMACOLOGY Dr. Salma Naqvi Asst. Prof., Pharmacology GMU, Ajman Learning objectives: Definition and introduction to pharmacological terms like: Pharmacology Drugs and receptors Pharmacokinetics Pharmacodynamics Pharmacogenomics Drug nomenclature Drug classification Sources of Drugs Sources of Drug Information  Introduction Pharmacology is the study of drugs and their effects on life processes. It is concerned with the interaction of chemical substances with living cells, tissues, and organisms. It is particularly the science of the mechanisms by which drugs counteract the manifestations of disease and other conditions (like fertility) In most of the pharmacologic specialties, drugs are also used today as tools to gain insight into both normal and abnormal function.  DRUGS A drug can be defined as a natural product, chemical substance, or pharmaceutical preparation intended for administration to a human or animal to diagnose or treat a disease. A drug can also be a biologic, for example, a preparation of monoclonal antibodies. Drugs may be hormones, neurotransmitters, or peptides produced by the body Drugs can be stimulatory or inhibitory  DRUGS contd.. Drugs, as well as hormones, neurotransmitter, autocoids and toxins can make possible the transfer of information to cells by interaction with specific receptive molecules called “receptors”. Drugs interact with biological systems in ways that mimic, resemble or otherwise affect the natural chemicals of the body. Drugs can produce effects by virtue of their acidic or basic properties (e.g. antacids), ability to denature proteins (astringents), osmotic properties (laxatives, diuretics), or physicochemical interactions with membrane lipids (anesthetics). RECEPTORS Most drugs combine/ bind with specific receptors to produce a response. This binding takes place by precise physicochemical interactions between specific groups of the drug and the receptor.  PHARMACOKINETICS Pharmacokinetics can be described as what the body does to the drug. It is concerned with the processes that determine the concentration of drugs in body fluids and tissues over time The magnitude of the pharmacological effect of a drug depends on its concentration at the site of action. It includes: Absorption Distribution Metabolism Excretion  PHARMACODYNAMICS Pharmacodynamics can be described as what the drug does to the body. Associated with therapeutic effects, side/ adverse effects, toxicity Interaction of drugs with cellular proteins, such as receptors or enzymes, to control changes in physiological function of particular organs. Drug-Receptor Interactions oBinding Dose-Response oEffect Signal Transduction oMechanism of action, Pathways  Pharmacogenetics & Pharmacotherapeutics PHARMACOGENETICS: Area of pharmacology concerned with unusual responses to drugs caused by genetic differences between individuals. Responses that are not found in the general population, such as general toxic effects, allergies, or side effects, but due to an inherited trait that produces a diminished or enhanced response to a drug. PHARMACOTHERAPEUTICS: is the medical science concerned with the use of drugs in the treatment of disease. Pharmacology provides a rational basis for pharmacotherapeutics by explaining the mechanisms and effects of drugs on the body and the relationship between dose and drug response.  DRUG NOMENCLATURE Chemical name describes the chemical nature of the drug e.g. Acetylsalicylic acid. For most drugs, medicinal chemists primarily use the chemical name. Non–proprietary or Generic name is the name accepted by a scientific bodies / regulatory agencies of the world Example: Aspirin. Most suitable for use by health care professionals. In the United States, the generic names of drugs are the United States Adopted Name (USAN) designations. Proprietary or Brand name is the registered trademark assigned by the manufacturer. The same drug has so many brand names. They may be used in prescriptions. Example: Disprin, Ecosprin etc.  DRUG CLASSIFICATION Prescription drugs: Can be obtained only through a prescription. e.g. Antimicrobials, antipsychotics, sedatives + (all habit-forming drugs). Over-the-counter drugs (OTC drugs): Permitted to be sold without a doctor’s prescription. Therefore, also called non– prescription drugs Examples: Paracetamol, antacids, vitamins etc.  SOURCES OF DRUGS PLANTS: Alkaloids: Morphine, Atropine, Quinine (antimalarial) Cardiac glycosides: Digoxin Animals: Insulin (anti-diabetic), Heparin (anticoagulant) Minerals: Calcium carbonate, Magnesium sulphate, Iron Microorganisms: Penicillin (antibacterial), Streptomycin (anti-tubercular)  SOURCES OF DRUGS contd.. Semisynthetic Sources: Hydromorphone (opioid analgesic) Synthetic Sources: Paracetamol (antipyretic), Aspirin (NSAID & anti-platelet) Drugs produced by Genetic Engineering: Human insulin, Hepatitis B vaccine, Human growth hormone  SOURCES OF DRUG INFORMATION Pharmacopoeia: It is an official book of approved drugs with description of their physical & chemical characteristics, tests for their identification, purity, methods of manufacturing & storage etc. Many countries have their own Pharmacopoeias. E.g., United States Pharmacopoeia (USP), British Pharmacopoeia (BP), Indian Pharmacopoeia (IP). Formularies: Produced in booklet forms, They list indications, dose, dosage forms, precautions, adverse effects, toxicity etc. Example: British National Formulary (BNF), National Formulary of India Martindale: The complete drug Reference book