C H A P T E R 4 7
Lipid-lowering agents
739
Prototype summary: Cholestyramine
Indications:
Reduction of elevated serum cholesterol
in people with primary hypercholesterolaemia;
pruritus associated with partial biliary obstruction.
Actions:
Binds with bile acids in the intestine,
allowing excretion in faeces instead of reabsorption,
causing cholesterol to be oxidised in the liver and
serum cholesterol levels to fall.
Pharmacokinetics:
Not absorbed systemically.
T
1/2
:
Not absorbed systemically, excreted in faeces.
Adverse effects:
Rash, headache, anxiety, vertigo,
dizziness, constipation due to faecal impaction,
exacerbation of haemorrhoids, cramps, flatulence,
nausea, increased bleeding tendencies, vitamin A
and D deficiencies, muscle and joint pain.
Care considerations for
people receiving bile acid sequestrants
Assessment: History and examination
■
■
Assess for contraindications or cautions: known
allergies to these drugs
to avoid hypersensitivity
reactions
; impaired intestinal function,
which
could be exacerbated by these drugs
; biliary
obstruction,
which could block the effectiveness
of these drugs
; and current status related to
pregnancy and breastfeeding
because of the
potential for adverse effects on the fetus or
breastfeeding baby
.
■
■
Perform a physical assessment
to establish a
baseline before beginning therapy and during
therapy to determine the effectiveness of therapy
and evaluate for any potential adverse effects.
■
■
Weigh the person
to establish a baseline and
evaluate for changes reflecting lifestyle changes
that accompany drug therapy
.
■
■
Inspect the person’s skin for colour, bruising and
rash
to evaluate for possible adverse effects.
■
■
Assess neurological status, including level of
orientation and alertness,
to determine any central
nervous system effects.
■
■
Monitor pulse and blood pressure
for changes
related to changes in CAD risk factors.
■
■
Inspect the abdomen for distension and auscultate
bowel sounds
for changes in gastrointestinal
motility.
■
■
Assess bowel elimination patterns, including
frequency of stool passage and stool characteristics,
to identify possible constipation and faecal
impaction.
■
■
Monitor the results of laboratory tests, including
serum cholesterol and lipid levels,
to evaluate the
effectiveness of drug therapy.
Implementation with rationale
■
■
Do not administer powdered agents in dry
form;
these drugs must be mixed in fluids to be
effective.
Mix with fruit juices, soups, liquids,
cereals or pulpy fruits. Mix colestipol, but not
cholestyramine, with carbonated beverages. Stir,
and encourage the person to swallow all of the
dose.
■
■
If the person is taking tablets, ensure that tablets
are not cut, chewed or crushed
because they are
designed to be broken down in the GI tract; if
they are crushed, the active ingredients will not be
effective.
Urge the person to swallow tablets whole
with plenty of fluid.
■
■
Give the drug before meals
to ensure that the drug
is in the GI tract with food.
■
■
Administer other oral medications 1 hour before
or 4 to 6 hours after the bile sequestrant
to avoid
drug–drug interactions.
■
■
Arrange for a bowel program as appropriate
to
effectively deal with constipation if it occurs.
■
■
Provide comfort measures
to help the person
tolerate the drug effects.
These include small,
frequent meals to reduce the risk of nausea;
ready access to bathroom facilities to prevent
constipation; safety precautions to prevent injury
if dizziness, central nervous system (CNS) changes
or bleeding is a problem; replacement of fat-soluble
vitamins; skin care as needed; and analgesics for
headache.
■
■
Offer support and encouragement
to help the
person deal with the diagnosis and the drug
regimen and lifestyle changes that may be
necessary;
refer to services that might help with
the high cost of these drugs.
■
■
Provide thorough teaching, including the name
of the drug, dosage prescribed and schedule for
administration; method to administer the drug,
such as mixing the powder form in fluids or
taking tablets whole (without crushing, chewing
or cutting); appropriate fluids for mixing drug;
measures to avoid adverse effects, warning signs of
problems, and the need for follow-up laboratory
testing
to monitor cholesterol and lipid levels;
dietary and lifestyle changes for risk reduction
;
and monitoring and evaluation
to enhance
knowledge about drug therapy and to promote
compliance.
