patients should be warned against driving or operating
machinery while taking this type of medication. (See
appendix IV, page 2.)
HISTAMINE H2 RECEPTOR ANTAGO-
NISTS. Histamine H2 receptor antagonists block
histamines that cause an increase of gastric acid
secretion in the stomach.
Histamine H2 receptor
antagonists are effective in preventing complications
of peptic ulcer disease and alleviating symptoms of
this disease. (See appendix IV, page 2.)
ANTACIDS.Antacids are drugs used to
counteract hyperacidity in the stomach. Normally,
there is a certain degree of acidity in the stomach. An
excess of acid can irritate the mucous membranes and
is commonly known as indigestion, heartburn, or
dyspepsia. In some disease states, the gastrointestinal
tract may become excessively acidic (very low pH),
causing diarrhea or leading to peptic ulcer formation.
Antacids may interfere with the bodys ability to use
many drugs. For this reason, oral drugs normally
should not be taken within 2 hours of taking an antacid.
(See appendix IV, page 3.)
NOTE: It is important for you to be aware of
the significance of the sodium content of most
antacids, particularly for cardiac patients or
patients on a low-sodium diet.
ANTISEPTICS, DISINFECTANTS, AND
GERMICIDES.These agents are primarily
intended for the prevention of infections by destroying
bacteria or preventing their growth. The differences
among them are based primarily on degree of activity
and how they are used.
Antiseptics suppress the
growth of microorganisms.
susceptible organisms. Disinfectants are agents used
to disinfect inanimate objects and are primarily
germicidal in their action. All of these agents are for
external use only, unless otherwise indicated. (See
appendix IV, pages 3 and 4.)
SULFONAMIDES.Sulfonamides were the
first effective chemotherapeutic agents to be available
in safe therapeutic dosage ranges.
They were the
mainstay of therapy of bacterial infections in humans
before the introduction of the penicillins in 1941.
Sulfonamides are synthetically produced and are
effective against both g r a m - p o s i t i v e a n d
gram-negative organisms. (See appendix IV, page 5.)
PENICILLINS.Penicillin is one of the most
important antibiotics. It is derived from a number of
Penicillium molds commonly found on breads and
fruits. The mechanisms of action for the penicillins is
the inhibition of cell wall synthesis during the
reproductive phase of bacterial growth. It is one of the
most effective and least toxic of the antimicrobial
agents. (See appendix IV, page 5.)
CEPHALOSPORINS.The cephalosporins are
a group of semisynthetic derivatives of cephalosporin
C, an antimicrobial agent of fungal origin. They are
structurally and pharmacologically related to the
Because the cephalosporins are
structurally similar to the penicillins, some patients
allergic to penicillin may also be allergic to cephalo-
sporin drugs. The incidence of cross-sensitivity is
estimated to be 5 to 16 percent.
This family of antibiotics is generally divided into
First generation cefazolin sodium (Ancef®,
Second generation cefoxitin sodium
Third generation cefotaxime sodium
The main differences among the groups is the
change in the antibacterial spectrum.
generation agents have a much broader gram-negative
spectrum than the earlier generations.
Examples of various cephalosporins are listed in
appendix IV, page 6.
T E T R A C Y C L I N E S . Te t r a c y c l i n e s ,
introduced in 1948, were the first truly broad-spectrum
antibiotics. They include a large group of drugs with a
common basic structure and chemical activity. The
most important mechanism of action of the
tetracyclines is the blocking of the formation of
polypeptides used in protein synthesis. Because of
their broad spectrum of activity, tetracyclines are most
valuable to treat mixed infection, such as chronic
bronchitis and peritonitis; however, they are drugs of
choice for only a few bacterial infections. Tetracycline
is also used as a topical preparation to treat acne.
The tetracyclines are relatively nontoxic, the most
common side effects being mild gastrointestinal
disturbances. Allergic reactions and anaphylaxis are
rare. Administration to children and pregnant women
is not indicated because it may produce discoloration
of the teeth and depress bone marrow growth. The
major hazard of tetracycline therapy is the overgrowth
of resistant organisms, especially Candida and