CHAPTER 7 PHARMACOLOGY AND TOXICOLOGY
INTRODUCTION
As you advance in rate, you will become more and more involved with the intricacies of administering medicines. Although the drugs and their dosages are prescribed by the medical officer and other authorized prescribers, you, as the hospital corpsman, are involved in their administration. It is necessary for you to learn their sources, composition, methods of preparation and administration, and physiologic and toxicologic action. This chapter is concerned primarily with the action, use, and dosage of drugs.
The subject of pharmacology was known as Materia Medica until 1890 when the current term began to come into use. The subsciences of pharmacology and their specific fields of study are as follows:
PHARMACOGNOSCY.—The recognition, quality, purity, and identification of drugs.
PHARMACY.—The preparation, stability, preservation, and storage of pharmaceutical preparations.
POSOLOGY.—Dosage or amount of drug to be given.
PHARMACODYNAMICS.—The response of living tissue to chemical stimulation in the absence of disease. This almost exclusively deals with research and development.
PHARMACOTHERAPEUTICS.—The action of drugs on living tissue in the presence of disease; treatment of the sick.
TOXICOLOGY.—The toxic or poisonous effects of substances.
The art of treating disease by any method that will relieve pain, cure disease, or prolong life is called therapeutics. Although the average person thinks solely of giving or taking medicine in this respect, it must be remembered that therapy also includes other methods, such as radiological treatment, diathermy, hydrotherapy, and many more.
DRUG STANDARDS
The texts dealing with pharmaceutical preparations include the United States Pharmacopoeia and National Formulary (USP-NF) which provides standards for drugs of therapeutic usefulness and pharmaceutical necessity. Inclusion of drugs into this compendia is based on therapeutic effectiveness and popularity. It provides tests for identity, quality, strength, and purity.
The Physicians’ Desk Reference is a multiple index of commercially available drugs and is used as an advertising outlet for various drug manufacturers. Pharmaceutical preparations are described as to composition, action and use, administration and dosage, precautions and side effects, dosage forms available, and the common (generic) name of the drug.
Remington’s Pharmaceutical Sciences is probably the most widely used text/reference in American pharmacy. It contains all areas relevant to the art/science of pharmacy. The Pharmaceutical Basis of Therapeutics (Goodman and Gilman) is a textbook of pharmacology, toxicology, and therapeutics known as the “blue bible” of pharmacology.
MEDICATION ADMINISTRATION
The quantity of a drug to be administered at one time or the total quantity administered and the method of administration of drugs is dependant upon several factors. This section will cover some of the methods of administration and some of the factors affecting dosage calculations.
DOSAGE
The amount of medication to be administered is referred to as the dose. The study of dosage and the criteria which influence it is called posology. The doses given in the United States Pharmacopoeia and National Formulary (USP-NF) are average therapeutic doses and are known as