b. To Reverse a Disease Process. Antibiotics and chemotherapeutic
(anticancer) agents are commonly used in medicine today. Ideally we would like these
agents to cure the patient.
c. To Relieve Symptoms. Drugs that act to relieve symptoms do not cure the
patient. Instead, they help to make the patient more comfortable in order for the patient
to work or function. Since only symptoms are being relieved, the body is expected to
remedy the problem.
d. To Prevent Disease. Vaccines and toxoids are used to prevent disease. In
the 1950's, many parents kept their children at home in fear of the dreaded polio
disease. Today, the only time most parents think of polio is when they take their
children for their periodic (and necessary) vaccinations for this still-present threat.
Further, any military veteran can quickly testify to the fact that vaccinations are an
essential part of the introduction to military life.
e. To Prevent Pregnancy. The old saying that an ounce of prevention is better
and cheaper than a pound of cure is most applicable here. The birth control "pill" or oral
contraceptives and spermacidal agents in the form of creams, jellies, and suppositories
are the drugs currently being used to prevent pregnancy.
Section III. CONSIDERATIONS OF DRUG THERAPY
3-5. FACTORS WHICH INFLUENCE DRUG DOSAGE EFFECTS
Many factors influence how a dose of a particular drug will affect a patient. Since
not all patients are the same size, weight, age, and sex, it would be wise to consider
how these factors might influence how much drug a person should receive and the
effect(s) that drug might have on the patient. The usual recommended adult dose of
medication, as found in standard references, is based on the assumption that the
patient is a "normal" adult. Such a "normal" (or average) adult is said to be 5 feet 9
inches (173 centimeters) tall and weigh 154 pounds (70 kilograms). However, many
people do not fit into this category. Therefore, the following factors should be
considered when patients receive drugs:
a. Weight. Obese (overweight) patients may require more medication than thin
patients may because the drug has more tissue to which it can go. The dosage of many
drugs is calculated on a weight basis. For example, a person might be prescribed a
drug that has a dosage of 5 milligrams of drug per pound of patient body weight.
b. Surface Area. A person's height and weight are related to the total surface
area of his body. The "normal" (average) adult has a body surface area of
approximately 1.73 square meters. A nomogram (see Subcourse MD08O2,
Pharmaceutical Calculations) is used to determine the surface area of a patient. The