PHARMACOLOGY

 INTRODUCTION ::

Fighting disease with drugs is an endless task that originated from the existence of mankind materia medica was the term previously used for the study of all materials used in medicine The term dealt with source identification and preparation of drugs and such materials as feeding cup enemata can thermometer etc used in treatment of diseases it is a vague term and is now obsolete pharmacology is relatively a new term derived from the Greek word pharmacon means a drug and logos meaning a discourse or study 

    Pharmacology is the science which deals with the action of drugs on a living organism its organs or tissues it tries to explain when where how and why of drug action the body cells participating in the process in a broad sense pharmacology incorporates history and source physical and chemical characteristics biochemical and physiological actions with their mechanism absorption biotransformation and excretion with its therapeutics but strictly speaking it studies actions and effects of drugs 

    A drug is defined as a chemical agent that affects living processes Even poison and toxins are also drugs under this definition in fact any drug in high dose can produce poisonous or harmful effect in medical science a drug is defined as a chemical agent used for diagnosis prevention treatment and cure of a disease or for the relief of its symptoms 

        Action of drugs on cells implies the interactions of the cell with the drug and the effect which the drug often used as synonyms is the consequence of drug action However a drug is a single chemical entity that may be one of the constituents of a medicine A medicine may contain one or more active constituents (drugs) together with additives to facilitate administration (colour flavour and other excipients )