The immunization consists of three subcutaneous
injections given 2 weeks apart, followed by three
additional subcutaneous injections given at 6, 12, and
18 months. Annual booster injections of the vaccine
are required to maintain immunity.
LEARNING OBJECTIVE: Identify how
poisons are introduced into the body and the
factors that affect their toxicity.
Toxicology is the science of poisons, their actions,
their detection, and the treatment of the conditions
produced by them. A poison is a substance that, when
inhaled, swallowed, absorbed, applied to the skin, or
injected into the body in relatively small amounts, may
cause damage to structures or disturbances of function.
Poisons act by changing the normal metabolism of
cells or by actually destroying them.
The effects of poisons may be local or remote, and
in some instances, poisons can produce both effects. A
local effect is produced when a poison only affects the
area in which it is applied. A remote effect is produced
when a poison affects parts of the body that are remote
to the site of application or point of introduction.
Poisons sometimes show no effector only a slight
effectuntil several doses have been taken. Then,
suddenly, an effect is produced that nearly equals that
produced by taking the whole amount at one time. This
is known as a cumulative effect.
The toxicity of poisons depends upon their method
of introduction into the body and how fast they are
absorbed by the body. For example, snake venom
taken into the mouth or into the stomach during first aid
treatment of snakebite is not ordinarily harmful, but
snake venom injected parenterally is extremely
Various conditions affect an individuals reaction
and susceptibility to poisons. For instance, some
individuals by nature are unusually sensitive to certain
poisons (such as venom from bee stings), while others
possess a natural tolerance. Additionally, the age of
the victim can affect the severity of the poisoning.
Young children, for example, are normally more
susceptible to poisons than adults. Habitual use of
certain poisons, such as narcotics, may cause
individuals to become accustomed to a poisons
effects, even though the amount taken by these
individuals would ordinarily be considered lethal.
This habitual use of poisons, however, may result in a
sudden hypersensitivity that could be deadly.
actions of poisons may also be considerably modified
by disease, some diseases increasing and others
lessening the action of poisons.
Poisons are eliminated from the body by way of the
kidneys, liver, gastrointestinal tract, and skin. Poisons
are eliminated either unchanged or in the form of other
These compounds are the result of
chemical changes made in various body organs and
For a more in-depth understanding of the various
types of poisoning and their emergency treatment
procedures, see chapter 5, Poisoning, Drug Abuse,
and Hazardous Material Exposure.
v a r i o u s p h a r m a c e u t i c a l w e i g h t a n d
measurement systems, and determine
medication dosage by using the conversion
process or the percentage and ratio
As you progress in your career as a Hospital
Corpsman, you will be assigned duties in specialized
departments throughout the hospital and especially
Not only will your responsibilities
increase, but your training will become more and more
One of the departments to which you may be
assigned is the pharmacy, where you will assist in
preparing and dispensing medicines. This section will
give you a basic introduction to the field of pharmacy
and help prepare you for these responsibilities.
METROLOGY AND CALCULATION
Metrology, called the arithmetic of pharmacy, is
the science of weights and measures and its application
to drugs, their dosage, preparation, compounding, and
It is absolutely vital for Hospital Corpsmen to
thoroughly understand the principles and applications
of metrology in pharmacy. Errors in this area endanger
the healtheven the lifeof the patient.