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P A R T 1 1
Drugs acting on the gastrointestinal system
■■
The prostaglandin misoprostol is used to inhibit
gastric acid secretion and increase bicarbonate and
mucus production in the stomach; this action will
protect the lining of the stomach.
■■
This drug increases prostaglandin effects in the
uterus, causing increased contractions, excessive
bleeding and cramping. This drug is pregnancy
category X and cannot be used during pregnancy.
DIGESTIVE ENZYMES
Digestive enzymes
(Table 57.2) are substances produced
in the GI tract to break down foods into usable nutri-
ents. Some people—with cystic fibrosis or pancreatic
dysfunction resulting from surgery or illness—may
require a supplement to the production of digestive
enzymes. Pancrelipase (
Creon
,
Panzytrat
) is available for
KEY POINTS
replacement in conditions that result in lower-than-nor-
mal levels of these enzymes.
Therapeutic actions and indications
The pancreatic enzymes are replacement enzymes that
help the digestion and absorption of fats, proteins and
carbohydrates (see Figure 57.1). See Table 57.2 for usual
indications for each agent.
Pharmacokinetics
Pancrelipase, which is available in capsules, delayed
release capsules, granules and tablet form, is thought to
be processed through normal metabolic systems in the
body. Little is known about its pharmacokinetics.
Contraindications and cautions
Pancreatic enzymes should not be used with known
allergy to the product or to pork products
to prevent
hypersensitivity reactions
. In addition, pancreatic
enzymes should be used cautiously in pregnancy and
breastfeeding
because of the risk for adverse effects on
the fetus or baby
.
Adverse effects
The adverse effects that most often occur with pancre-
atic enzymes are related to GI irritation and include
nausea, abdominal cramps and diarrhoea.
measures such as small, frequent meals and
increased fluid intake to alleviate or minimise
adverse GI effects; danger signs to report to the
healthcare provider immediately; support to deal
with changes in sexuality patterns that may occur;
and the importance of periodic monitoring and
evaluation
to enhance knowledge about drug
therapy and to promote compliance.
Evaluation
■
■
Monitor the response to the drug (prevention of
GI ulcers related to NSAIDs).
■
■
Monitor for adverse effects (GI, genitourinary).
■
■
Monitor the effectiveness of comfort and safety
measures and compliance with the regimen.
■
■
Evaluate the effectiveness of the teaching plan
(person can name drug and dosage and describe
adverse effects to watch for, specific measures to
avoid them and measures to take to increase the
effectiveness of the drug).
TABLE57.2
DRUGS IN FOCUS Drug used to treat digestive enzyme dysfunction
Drug name
Dosage/route
Usual indications
Digestive enzymes
pancrelipase (Creon,
Panzytrat)
Adult: 4000–48,000 units PO with each meal
and snacks
Paediatric: 6 months–1 year: 2000 units PO
per meal
1–6 years: 4000–8000 units PO with meals,
4000 units with snacks
7–12 years: 4000–12,000 units PO with each
meal and snack
Aids digestion and absorption of fats,
proteins and carbohydrates in conditions
that result in a lack of this enzyme; used
as replacement therapy in people with
cystic fibrosis, chronic ductal obstruction,
pancreatic insufficiency, steatorrhoea
or malabsorption syndrome and after
pancreatectomy or gastrectomy
Prototype summary: Pancrelipase
Indications:
Replacement therapy in people with
deficient exocrine pancreatic secretions.
Actions:
Replaces pancreatic enzymes to aid in
the digestion and absorption of fats, proteins and
carbohydrates.
Pharmacokinetics:
Generally not absorbed
systemically.
T
1/2
:
Generally not absorbed systemically.
Adverse effects:
Nausea, abdominal cramps,
diarrhoea, hyperuricosuria.
