DRUG CLASSIFICATIONS
LEARNING OBJECTIVE: Recall drug
groups, the generic and trade names of
drugs listed in each drug group, and
recognize each drugs use.
The definition of a drug is any chemical substance
that has an effect on living tissue but is not used as a
food. Drugs are administered to humans or animals as
an aid in the diagnosis, treatment, or prevention of
disease or other abnormal condition; for the relief of
pain or suffering; and to control or improve any
physiologic or pathologic condition.
Drugs are
classified according to set criteria and fall into three
specific areas: general, chemical, and therapeutic.
GeneralDrugs are grouped according to their
source, whether animal, vegetable, or mineral in
origin.
ChemicalDrugs are grouped by their
chemical characteristics.
Therapeutic (Pharmacological)Drugs are
grouped according to their action on the body.
NOTE: Some drugs may have more than
one action.
Drug Nomenclature
Drugs normally have three names:
chemical,
generic, and trade (brand).
Chemical name relates to the chemical and
molecular structure.
An example is
2,4,7-triamino-6-phenylpteridine.
Generic name is often derived from the
chemical name. Generic name is the common
name of the drug. An example is triamterene.
(Note the underlining of the chemical name
above.)
Trade name is the proprietary name given by
the manufacturer. Trade name is referred to as
the brand name. An example is Dyrenium®, a
brand of triamterene made by SmithKline
Beecham.
Drug Groups
The types of drugs discussed in this chapter and the
correlating drugs in common use described in
a p p e n d i x
I V
a r e
g r o u p e d
a c c o r d i n g
t o
pharmacological classes. Only a brief summary is
possible here, and the Corpsman who desires a more
complete description of each drug should refer to the
U S P - N F, D r u g F a c t s a n d C o m p a r i s o n s , the
Physicians Desk Reference, or other drug reference
books.
ASTRINGENTS.Astringents are drugs that
cause shrinkage of the skin and mucous membranes.
Astringents are mainly used to stop seepage, weeping,
or discharge from mucous membranes. (See appendix
IV, page 1.)
EMOLLIENTS.Emollients are bland or fatty
substances that may be applied to the skin to make it
more pliable and soft. They may also serve as vehicles
for application of other medicinal substances.
Emollients are available as ointments, creams, or
lotions. (See appendix IV, page 1.)
EXPECTORANTS AND ANTITUSSIVES.
Expectorants and antitussives are commonly used in
the symptomatic treatment of the common cold or
bronchitis. (See appendix IV, page 1.) Expectorants
are more accurately known as bronchomucotropic
agents. These agents assist in the removal of secretions
or exudate from the trachea, bronchi, or lungs. They
act by liquefying viscid mucous or mucopurulent
exudates. Therefore, they are used in the treatment of
coughs to help expel these exudates and secretions.
Antitussives are agents that inhibit or suppress the act
of coughing. Other cold and allergy relief preparations
are discussed later in this chapter.
NASAL DECONGESTANTS.Nasal decon-
gestants reduce congestion and the swelling of mucous
membranes. They are used for the temporary relief of
nasal congestion due to the common cold, nasal
congestion associated with sinusitis, and to promote
nasal or sinus drainage. Nasal decongestants are also
used to relieve eustachian tube congestion.
Nasal
decongestants are often combined with antihistamines,
antitussives, and expectorants to relieve the symptoms
of colds, allergies, and sinusitis. Some of the more
frequently used drug combinations are covered in
appendix IV, page 2.
ANTIHISTAMINES.Antihistamines are used
to counteract the physical symptoms that histamines
cause. Histamine, a substance released by mast cells
distributed in connective tissues usually near blood
vessels, promotes some of the reactions associated
with inflammation and allergies, such as asthma and
hay fever. Antihistamines may cause drowsiness, so
6-4