CHAPTER ONE INTRODUCTION DEFINITION OF TERMS Pharmacology:- This is the science that deals with the study of drugs in ail its scientific aspects, with specific references to the groups, and modes of action of the drugs in the body both in health and in disease, including their names, sources, physical and chemical properties. Drug:- This is a chemical substance taken into the body or applied to the body surface, not as food but for the prevention, contro! and treatment of disease symptoms or for diagnostic purposes. Pharmacy:- This is the scientific study of how drugs are presented in a form suitable for administration to the patients. Pharmacists:- These are personnel who are trained in and have a legal duty to enforce the various laws governing the production, distribution, storage and dispensing of medicines. Dispensing:- This is an aspect of pharmacy which involves the production of mixtures, ointments and sterile preparations from their various constituents. Toxicology:- This is the scientific study of harmful or poisonous effect of the drugs in the body, when given in excessive amounts. Toxicology is also the study of doses of drugs large enough to endanger life. Toxicity of drugs:- This is the exhibition of unwanted drug reaction arising from drug misuse or administration. This can be very fatal if not combated on time. For example, Barbiturates can accumulate in the liver due to excessive intake, and damage the liver tissue. Pharmatherapeutic:- This is the scientific study of how drugs are used in diagnosis, treatment and prevention of diseases. Therapeutics:- This is the art of employing remedies in the treatment of diseases and which involves care of the patient for the restoration of his health and to relieve him of his symptoms, even in situation where the disease cannot be cured. Hallucinogenic:- This is the tendency of a drug to produce auditory a or visual hallucinations. Psychotomimetic:- This is the ability of a drug to chemically induce symptoms of psychosis. BRITISH PHARMACOPOEIA (B.P.):- This is pharmaceutical compendium which contains list of official drugs and their doses as published by the General Medical council. Certain chemical standards were laid down by this council and which must be maintained in the manufacture of all drugs labelled B.P.The drugs labelled B.P. are referred to as approved drugs, while the names given to them are also referred to as Approved names. All drugs labelled BP are reviewed from time to time. PROPRIETARY NAME: - This is the name given to particular drugs by the manufacturing or pharmaceutical company which manufactured the drugs. It is to be noted, however, that all other drugs manufactured by other manufacturing companies apart from those produced by the British pharmacopoeia are also given names and later recognized. TOLERANCE:-This is the tendency to increase drug dosage to experience same effect formerly produced by a smaller dose or this is the progressive resistance created by the body to a particular drug, in which the normal dosage of the drug becomes ineffective unless its dosage is increased. With tolerance, there is the capacity to endure a poison or drug which later becomes harmful if taken in excess. Tolerance can be natural or acquired. Natural Tolerance implies that the individual resists the action of a certain drug and can tolerate much larger doses than anormal person, Acquired Tolerance is a state induced in the normal person by the prolonged use of a drug whereby he gradually tolerates increasing doses which would, if administered in the first place, have produced toxic symptoms. Patients vary in their response to drugs. This variability is due to three principal factors like (1) the disease in terms of severity and complications (2) the responsiveness of the tissues to the drug and (3) the concentration of the drug at its site of action. The intake of larger and larger doses of drugs in order to gain and maintain their desired effect, based on tolerance, becomes a kind of drug abuse. Tolerance is partly the result of an increased capacity of the body to metabolize and eliminate the drug. This is to say that the body cells and tissues of such an individual are able to adapt somehow to the presence of high dosage of the drug and are still able to function more or less normally. After sometime, people who have tolerance to certain drugs reach their dose limits with such drugs resulting in intoxication and even death. The most important aspect of tolerance is the fact that it leads to physical Dependence. PHYSICAL DEPENDENCE:- This is a state or phenomenon in an individual which makes him seek certain drugs. This behaviour makes the individual susceptible to drug abuse. The presence of a particular drug becomes necessary to maintain a normal state of activities in such an individual. Physical or Physiological Dependence is an adaptive Physiologic state occurring after prolonged use of a drug; discontinuation causes intense physical disturbances that are relieved by really ministering the same drug or a pharmacologically related drug. SIDE EFFECTS:- The side effect which is otherwise known as Adverse 2Effect or unwanted effect or unavoidable effect is the negative con presented by an individual after the intake of normal dose of a pr drug. PHARMACOKINETICS: - Pharmacokinetics according to M Salerno (1955) is the study of the concentration of a drug dur processes of absorption, distribution, biotransformation and excret further stated that the concentration that a drug attains at its site of is influenced by four primary factors. These include the rate and e: which a drug is: : (1) absorbed into body fluids. (2) distributed to sites of action or storage areas. (3) biotransformed or metabolized to break down products. (4) excreted from the body by various routes. PHARMACODYNAMICS: - This is the study of the mechanism of action on living tissues. It is concerned with the responses of tissue: specific chemical agents at various sites in the body. The mode of a of action explains how the drug acts at the biochemical or cellular ley produce its therapeutic effects. PLACEBO: - According to Mckenry and Salerno (1955), is any treatm medication, surgical or diagnostic procedure or nursing action that elici properties. Examples include Lactose sugar, distilled water, normal saline ‘or a small dose of an innocuous substance such as a vitamin. REASONS FOR STUDYING PHARMACOLOGY IN NURSING (1) To enable the nurse have adequate knowledge about the mode oF mechanism of action of the various drugs (i.e. Pharmaco-dynamics) on living human body tissues. (2) To bring into focus the various.classifications or groups to which tl drugs belong to enhance quick application of these drugs to diver clinical manifestations presented by the patients. (3) To enable the nurses know the various uses of these drug (indications) in disease conditions. a (4) To enable the nurses know how they can apply their knowledge of mathematics in determining the correct doses (dosages) of the drugs to be: given to patients, based on age, body weight, severity of the illness ete, i order to bring the desired effects. (5) To accustom the nurses to the expected or undesired side effects (b effects) that these drugs can bring upon the human body. (6) To enable the nurses know the remedy to give (i.e. antidotes) t counteract or neutralize the side effects of the given drugs. (7) To familiarize the nurse with the various ways (routes) by which di can enter the body tissues, including the advantages and disadvai of these routes before drugs are administered, in order to achieve th 3NE desired effects. (8) To enable the nurses know the necessary precautions to take before and while administering the drugs, either to avert any danger or to enhance the good effects of the drugs. (9) To get the nurses acquainted with the specific conditions in which these drugs cannot be used (i.e. contraindications), in order not to aggravate the existing conditions. (10) To get the nurses familiar with the various terminologies used in the field of pharmacology for proper understanding of the course (Pharmacology) and its integration into nursing programme. (11) To bring*into nurses’ understanding, the various Abbreviations used in drug prescription for easy and adequate administration of drugs. (12) To enable the nurses know the various forms (or pharmaceutical preparations) of the available drugs (like Tablets, capsules, vaccines, ointments, powder etc) in the health industry and their application to specific conditions. (13) To equip the nurses with the knowledge concerning the factors that can influence the effects of drugs on the body tissues. e.g. body weight, Age, Sex, Immunological, Psychological, pathological, physiological, Environmental and Genetic factors etc. (14) To ensure that nurses are not left out concerning the administration and legal control of dangerous and poison drugs to reduce or eradicate the high incidence of mental illness caused by these drugs in our communities. (15) To equip the nurses with the pharmacological knowledge and its application in life-threatening situations like Anaphylaxis. (16) To quicken the nurses’ awareness about the concepts of drug abuse and drug addiction, including their prevention as well as the management of patients with drug abuse and drug addiction. (17) To enlighten the nurses about the various factors that can affect drug concentration level and the likely physiological effects of this concentration in the human body DEVELOPMENT OF PHARMACOLOGY OR HISTORY OF DRUG Drug is almost as o!d as the history of man. It was discovered that leaves, Barks of trees, roots and fruits have been used for medicinal purpose. |n actual sense, when the primitive men were searching for food, they soon got to know that parts of some plants caused some kinds of discomforts like vomiting, abdominal pain, diarrhoea etc. Based on these, findings, they started using these active substances from plants for their religious rites to drive out the disease — causing Evil Spirit from the sick people. The experience and knowledge acquired from using parts of Plants to make medicine or drug to cure specific diseases was then Passed on from generation to generation. As time went on, the need for the documentation of their findings 4