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P A R T 1 1
Drugs acting on the gastrointestinal system
■■
Antidiarrhoeal drugs are used to soothe irritation
to the intestinal wall; block GI muscle activity to
decrease movement; or affect CNS activity to cause
GI spasm and stop movement.
■■
Antidiarrhoeal drugs can cause GI discomfort and
constipation.
IRRITABLE BOWEL SYNDROME DRUGS
Irritable bowel syndrome (IBS) is a very common
disorder. It is experienced by three times as many
women as men and reportedly accounts for a large
number of all referrals to GI specialists. The disorder is
characterised by abdominal distress, bouts of diarrhoea
or constipation, bloating, nausea, flatulence, headache,
fatigue, depression and anxiety. No anatomical cause
has been found for this disorder. Underlying causes
might be stress-related. People with this disorder have
often suffered for years, not enjoying meals or activities
because of their GI pain and discomfort. Mebever-
ine (
Colese
,
Colofac
) is the most common drug used
to treat this condition. Other drugs are discussed in
Box 58.5.
KEY POINTS
Care considerations for
people receiving antidiarrhoeals
Assessment: History and examination
■
■
Assess for
possible contraindications or cautions
:
any history of allergy to these drugs
to prevent
hypersensitivity reactions
; acute abdominal
conditions,
which could be exacerbated by these
drugs
; poisoning,
which is a contraindication to
slowing GI activity
; hepatic impairment,
which
could alter the metabolism of the drug
; and current
status of pregnancy or breastfeeding,
which require
cautious use.
■
■
Perform a physical examination
to establish
baseline data before beginning therapy and during
therapy to determine the effectiveness of the drug
and to evaluate for the occurrence of any adverse
effects associated with drug therapy.
■
■
Inspect the skin for colour and evidence of lesions
or rash
to monitor for potential hypersensitivity
reactions.
■
■
Perform an abdominal examination, including
inspecting for distension, palpating for masses and
auscultating bowel sounds,
to evaluate GI function
and to rule out potential underlying medical
conditions.
■
■
Assess bowel elimination pattern, including
frequency and characteristics of stool,
to assist in
determining appropriateness for drug therapy.
■
■
Assess the person’s neurological status, including
level of orientation and affect,
to monitor for CNS
effects of the drug.
Implementation with rationale
■
■
Administer the drug after each unformed stool
to
ensure therapeutic effectiveness.
Keep track of the
exact amount given
to ensure that the dose does
not exceed the recommended daily maximum
dose.
■
■
Monitor the response carefully; note the frequency
and characteristics of the stool. If no response
is seen within 48 hours,
the diarrhoea could
be related to an underlying medical condition.
Arrange to discontinue the drug, and arrange for
medical evaluation
to allow for the diagnosis of
underlying medical conditions.
■
■
Provide appropriate safety and comfort measures
if CNS effects occur
to prevent injury.
■
■
Offer support and encouragement
to help the
person deal with the diagnosis and the drug
regimen.
■
■
Provide thorough teaching, including the drug
name and prescribed dosage; schedule for
administration; use of drug after each loose
stool; recommended daily maximum dose and
the need not to exceed it; signs and symptoms
of adverse effects, including measures to
minimise or prevent them; safety measures, such
as avoiding driving and obtaining assistance
with ambulation as needed
to reduce the risk
of injury due to weakness or dizziness
; danger
signs and symptoms that need to be reported
immediately; the importance of notifying
healthcare provider if diarrhoea is not controlled
within 48 hours; and the need for follow-up
to enhance knowledge about drug therapy
and to promote compliance.
Evaluation
■
■
Monitor the response to the drug (relief of
diarrhoea).
■
■
Monitor for adverse effects (GI effects, CNS
changes, dermatological effects).
■
■
Monitor the effectiveness of comfort and safety
measures and compliance with the regimen.
■
■
Evaluate the effectiveness of the teaching plan
(person can name the drug and dosage, as well
as describe adverse effects to watch for, specific
measures to use to avoid them and measures to
take to increase the effectiveness of the drug).
