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P A R T 1
Introduction to nursing pharmacology
Liver injury (hepatotoxicity)
Oral drugs are absorbed and passed directly into the
liver in the first-pass effect. This exposes the liver cells
to the full impact of the drug before it is broken down
or distributed throughout the body. Most drugs are
metabolised in the liver, so any active metabolites that
are toxic will also affect the integrity of the liver cells
(hepatocytes).
Assessment
Symptoms may include fever, malaise, nausea, vomiting,
jaundice, change in colour of urine or stools, abdomi
nal pain or colic, elevated liver enzymes (e.g. aspartate
aminotransferase [AST], alanine aminotransferase
[ALT]), alterations in bilirubin levels and changes in
clotting factors (e.g. partial thromboplastin time).
Interventions
Discontinue the drug and notify the prescriber and/or
primary caregiver. Offer supportive measures such as
small, frequent meals, skin care, a cool environment and
rest periods.
Renal injury (nephrotoxicity)
The glomerulus in the kidney has a very small capil
lary network that filters the blood into the renal tubule.
Some drug molecules can precipitate in the renal tubules
causing acute inflammation and severe renal problems.
Some drugs are excreted from the kidney unchanged;
they have the potential to directly affect the renal tubule
and alter normal absorption and secretion processes.
Gentamicin, a potent antibiotic, is frequently associated
with renal toxicity.
Assessment
Elevated blood urea nitrogen (BUN), elevated creatinine
concentration, decreased haematocrit, electrolyte imbal
ances, fatigue, malaise, oedema, irritability and skin
rash may be seen.
Interventions
Notify the prescriber and/or primary caregiver and
discontinue the drug as needed. Offer supportive
measures—for example, positioning, diet and fluid
restrictions, skin care, electrolyte therapy, rest periods,
a controlled environment. In severe cases, be aware that
dialysis may be required for survival.
Poisoning
Poisoning
occurs when an overdose of a drug damages
multiple body systems, leading to the potential for fatal
reactions. Assessment parameters vary with the par
ticular drug. Treatment of drug poisoning also varies,
depending on the drug. Throughout this book, specific
treatments for poisoning are identified, if known. Emer
gency and life support measures are often needed in
severe cases.
Alterations in glucose metabolism
All cells need glucose for energy; the cells of the central
nervous system are especially dependent on constant
glucose levels to function properly. The control of
glucose in the body is an integrated process that involves
a series of hormones and enzymes that use the liver as
the place for glucose storage or release. Many drugs
have an impact on glucose levels because of their effects
on the liver or the endocrine system.
Hypoglycaemia
Some drugs affect metabolism and the use of glucose,
causing a low serum blood glucose concentration, or
hypoglycaemia. Glipizide and glibenclamide are antidia
betic agents that have the desired action of lowering the
blood glucose level but can lower blood glucose too far,
causing hypoglycaemia.
Assessment
Symptoms may include fatigue; drowsiness; hunger;
anxiety; headache; cold, clammy skin; shaking and
lack of coordination (tremulousness); increased heart
rate; increased blood pressure; numbness and tingling
of the mouth, tongue and/or lips; confusion; and rapid
and shallow respirations. In severe cases, seizures and/or
coma may occur.
Interventions
Restore glucose—orally, if possible, or intravenously
(IV). Provide supportive measures (e.g. skin care,
environmental control of light and temperature, rest).
Institute safety measures to prevent injury or falls.
Monitor blood glucose levels to help stabilise the situa
tion. Offer reassurance to help the person cope with the
experience.
Hyperglycaemia
Some drugs stimulate the breakdown of glycogen or
alter metabolism in such a way as to cause high serum
glucose levels, or hyperglycaemia. Ephedrine (generic),
a drug used as a bronchodilator and antiasthma drug
and to relieve nasal congestion, can break down stored
glycogen and cause an elevation of blood glucose by its
effects on the sympathetic nervous system. Diazoxide,
a drug used for treatment of malignant hypertension,
causes a decrease in insulin release, leading to an
increase in blood glucose levels.
Assessment
Fatigue, increased urination (polyuria), increased thirst
(polydipsia), deep respirations (Kussmaul respirations),
restlessness, increased hunger (polyphagia), nausea, hot
or flushed skin and fruity breath odour may be observed.
Interventions
Administer insulin therapy to decrease blood glucose as
appropriate, while carefully monitoring glucose levels.
