C H A P T E R 5 7
Drugs affecting gastrointestinal secretions
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This drug is also contraindicated during pregnancy
because it is an abortifacient.
Women of childbearing
age should be advised to have a negative serum preg-
nancy test within 2 weeks of beginning treatment, and
they should begin the drug on the second or third day of
their next menstrual cycle. In addition, they should be
instructed to use barrier contraceptives during therapy.
Caution should be used during breastfeeding
because
of the potential for adverse effects on the newborn.
Caution also is necessary in people with hepatic or renal
impairment,
which could interfere with the effective
metabolism and excretion of the drug.
Adverse effects
The adverse effects associated with this drug are pri-
marily related to its GI effects—nausea, diarrhoea,
abdominal pain, flatulence, vomiting, dyspepsia and
constipation. Genitourinary effects, which are related
to the actions of prostaglandins on the uterus, include
miscarriages, excessive bleeding, spotting, cramping,
hypermenorrhoea, dysmenorrhoea and other menstrual
disorders. Women taking this drug should be notified,
both in writing and verbally, of these potential effects
of this drug.
Prototype summary: Misoprostol
Indications:
Prevention of NSAID- or aspirin-
induced gastric ulcers in people at risk for
complications of gastric ulcers.
Actions:
Inhibits gastric acid secretion and increases
bicarbonate and mucus production, protecting the
lining of the stomach; increases stimulatory effects
in the uterus.
Pharmacokinetics:
Route
Onset
Peak
Oral
Rapid
12–15 mins
T
1/2
:
20 to 40 minutes; metabolised in the liver and
excreted in urine.
Adverse effects:
Nausea, diarrhoea, abdominal pain,
flatulence, vomiting, excessive bleeding or spotting,
hypermenorrhoea, dysmenorrhoea, miscarriage.
Care considerations for
people receiving prostaglandin
Assessment: History and examination
■
■
Assess for
possible contraindications or cautions
:
any history of allergy to misoprostol
to prevent
hypersensitivity reactions
, and current status
of pregnancy or breastfeeding
because of the
potential for adverse effects on the fetus or
breastfeeding infant
.
■
■
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.
■
■
Examine the abdomen for possible changes
to rule
out medical conditions.
■
■
Perform a pregnancy test and assess normal
menstrual activity
to make sure that the woman is
not pregnant.
■
■
Monitor the results of laboratory tests, including
renal and hepatic function tests,
to determine the
need for possible dose adjustment and identify
toxic effects.
Implementation with rationale
■
■
Administer to people at high risk for NSAID-
induced ulcers during the full course of NSAID
therapy
to prevent the development of gastric
ulcers.
Administer four times a day, with meals and
at bedtime,
to ensure maximum benefit of the drug
.
■
■
Arrange for a serum pregnancy test within 2 weeks
before beginning treatment, and begin therapy on
the second or third day of the menstrual period,
to ensure that women of childbearing age are
not pregnant and to prevent abortifacient effects
associated with this drug.
■
■
Provide the woman with both written and oral
information regarding the associated risks of
pregnancy
to ensure that the woman understands
the risks involved
;
advise the use of barrier
contraceptives during therapy
to ensure the
prevention of pregnancy.
■
■
Evaluate nutritional status if GI effects are severe
to arrange for appropriate measures to relieve
discomfort and ensure nutrition
, such as small,
frequent meals, and increased fluid intake if
appropriate
.
■
■
Explain the risk of menstrual disorders and pain,
miscarriage and excessive bleeding
related to
the drug effects on prostaglandin activity in the
uterus.
■
■
Offer support and encouragement
to help the
person cope with the disease and the drug regimen.
■
■
Provide thorough teaching, including the drug
name and prescribed dosage; schedule for
administration; the need to take the drug with
meals and at bedtime; signs and symptoms
of adverse effects and measures to minimise
or prevent them; the importance of avoiding
pregnancy while taking drug; the use of barrier
contraceptives to prevent pregnancy; dietary
