C H A P T E R 3
Toxic effects of drugs
35
Other symptoms include difficulty swallowing, bad
breath, and pain in the mouth and throat.
Interventions
Provide frequent mouth care with a non-irritating
solution. Offer nutrition evaluation and development of
a tolerated diet, which usually involves frequent, small
meals. If necessary, arrange for a dental consultation.
Note that antifungal agents and/or local anaesthetics
are sometimes used.
Superinfections
One of the body’s protective mechanisms is provided
by the wide variety of bacteria that live within or on
the surface of the body. This bacterial growth is called
the
normal flora.
Normal flora protect the body from
invasion by other bacteria, viruses, fungi and so on.
Several kinds of drugs (especially antibiotics) destroy the
normal flora, leading to the development of
superinfec-
tions
, or infections caused by organisms that are usually
controlled by the normal flora.
Assessment
Symptoms can include fever, diarrhoea, a black or hairy
tongue, an inflamed and swollen tongue (glossitis),
mucous membrane lesions and vaginal discharge with or
without itching.
Interventions
Provide supportive measures (frequent mouth care, skin
care, access to bathroom facilities, small and frequent
meals). Administer antifungal therapy as appropriate.
In severe cases, discontinue the drug responsible for the
superinfection.
Blood dyscrasia
Blood dyscrasia
is bone marrow suppression caused by
drug effects. This occurs when drugs that can cause cell
death (e.g. antineoplastics, antibiotics) are used. Bone
marrow cells multiply rapidly; they are said to be rapidly
turning over. Because they go through cell division and
multiply so often, they are highly susceptible to any
agent that disrupts cell function.
Assessment
Symptoms include fever, chills, sore throat, weakness,
back pain, dark urine, decreased haematocrit (anaemia),
low platelet count (thrombocytopenia), low white blood
cell count (leucopenia) and a reduction of all cellular
elements of the full blood count (pancytopenia).
Interventions
Monitor blood counts. Provide supportive measures
(rest, protection from exposure to infections, protection
from injury, avoidance of activities that might result in
injury or bleeding). In severe cases, discontinue the drug
or stop administration until the bone marrow recovers
to a safe level.
KEY POINTS
■■
Adverse drug effects can include skin irritation
ranging from rashes and hives to potentially fatal
Stevens–Johnson syndrome. Adverse effects can be
predictable or unpredictable based on the mechanism
of action of the drug to its drug profile.
■■
Other adverse drug effects include superinfections,
or infections caused by destruction of protective
normal flora bacteria; blood dyscrasias caused by
bone marrow suppression of the blood-forming
cells; and stomatitis or mucous membrane
eruptions.
Toxicity
Introducing chemicals into the body can sometimes
affect the body very severely. These effects are not
acceptable adverse effects but are potentially serious
reactions to a drug. When a drug is known to have toxic
effects, the benefit of the drug to the person must be
weighed against the possibility of toxic effects causing
harm.
KEY POINTS
Teratogenicity
Ocular
damage
Stomatis
Allergic
reactions
Renal
damage
Liver
damage
Bone marrow
depression
Dermatological
reactions
Auditory
damage
Central nervous
system effects
FIGURE 3.1
Variety of adverse effects and toxicities associated with
drug use.
