Download CLINICAL PHARMACOLOGY OF GASTROINTESTINAL AGENTS

Clinical pharmacology of
gastrointestinal agents
Digestive diseases
Gastritis
Gastritis
Aspirin & NSAID Gastritis
Alcohol
Alcohol and certain other chemicals can cause
inflammation and injury to the stomach. This is
strictly dose related in that a lot of alcohol is
usually needed to cause gastritis. Social or
occasional alcohol use is not damaging to the
stomach although alcohol does stimulate the
stomach to make acid.
Gastritis treatment
Peptic ulcer disease (PUD) is a very common ailment,
affecting one out of eight persons in the United States. The
causes of PUD have gradually become clear. With this
understanding have come new and better ways to treat
ulcers and even cure them
PEPTIC ULCER DISEASE
Helicobacter pylori (H. pylori)
PEPTIC ULCER DISEASE
Symptoms
PEPTIC ULCER DISEASE
Therapy of PUD has undergone profound
changes. There are now available very effective
medications to supress and almost eliminate the
outpouring of stomach acid. These acidsuppresssing drugs have been dramatically effective
in relieving symptoms and allowing ulcers to heal. If
an ulcer has been caused by aspirin or an arthritis
drug, then no subsequent treatment is usually
needed. Avoiding these latter drugs, should prevent
ulcer recurrence.
The second major change in PUD treatment has
been the discovery of the H. pylori infection. When
this infection is treated with antibiotics, the
infection, and the ulcer, do not come back.
Increasingly, physicians are not just suppressing the
ulcer with acid-reducing drugs, but they are also
curing the underlying ulcer problem by getting rid of
the bacterial infection. If this infection is not
treated, the ulcers invariably recur.
There are a number of antibiotic programs available
to treat H. pylori and cure ulcers. Working with the
patient, the physician will select the best treatment
program available
Treatment of peptic ulcer
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Antimicrobial agents (tetracycline, bismuth subsalicylate, and
metronidazole) to eradicate H. pylori infection
Misoprostol (a prostaglandin analog) to inhibit gastric acid
secretion and increase carbonate and mucus production, to protect
the stomach lining
Antacids to neutralize acid gastric contents by elevating the
gastric pH, thus protecting the mucosa and relieving pain
Avoidance of caffeine and alcohol to avoid stimulation of gastric
acid secretion
Anticholinergic drugs to inhibit the effect of the vagal nerve on
acid-secreting cells
H2 blockers to reduce acid secretion
Sucralfate, mucosal protectant to form an acid-impermeable
membrane that adheres to the mucous membrane and also
accelerates mucus production
Dietary therapy with small infrequent meals and avoidance of
eating before bedtime to neutralize gastric contents
Insertion of a nasogastric tube (in instances of gastrointestinal
bleeding) for gastric decompression and rest, and also to permit
iced saline lavage that may also contain norepinephrine
Gastroscopy to allow visualization of the bleeding site and
coagulation by laser or cautery to control bleeding
Surgery to repair perforation or treat unresponsiveness to
conservative treatment, and suspected malignancy.
Ranitidine (Ranitidin)
Forms of production: 0,15 g and 0,3 g tablets and ampoules with 2 ml of
2,5 % solution.
RECOMMENDATIONS OF
HELICOBACTER PYLORI ERADICATION
A typical quadruple therapy
Ulcers associated with NSAIDs
 omeprazole 20mg daily is preferable to
ranitidine 150mg twice daily as the
respective rates of healing are 80% and
63%.
 H2RAs are slow to heal the ulcers if the
offending drug is not stopped and so,
under these conditions, a PPI is
preferred.
 H pylori eradication is no more effective
than omeprazole alone to heal ulcers, but
if the infection is present, then
eradication will reduce the rate of
relapse.
 H pylori is not associated with an
increased risk of ulcer with NSAIDs in the
elderly but there is an increased risk of
bleeding.
Motilium
Form of production: 0,01 g tablets
LAXATIVES AND CATHARTICS
Constipation can be defined
as infrequent or hard pellet
stools, or difficulty in
evacuating stool. Passing
one or more soft, bulky
stools every day is a
desirable goal. While
troublesome, constipation is
not usually a serious
disorder. However, there
may be other underlying
problems causing
constipation and, therefore,
testing is often
recommended.
Constipation
Indications for Use
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1. To relieve constipation in pregnant women, elderly
clients whose abdominal and perineal muscles have
become weak and atrophied, children with megacolon,
and clients receiving drugs that decrease intestinal
motility (eg, opioid analgesics, drugs with
anticholinergic effects)
2. To prevent straining at stool in clients with coronary
artery disease (eg, postmyocardial infarction),
hypertension, cerebrovascular disease, and
hemorrhoids and other rectal conditions
3. To empty the bowel in preparation for bowel surgery
or diagnostic procedures (eg, colonoscopy, barium
enema)
4. To accelerate elimination of potentially toxic
substances from the GI tract (eg, orally ingested drugs
or toxic compounds)
5. To prevent absorption of intestinal ammonia in
clients with hepatic encephalopathy
6. To obtain a stool specimen for parasitologic
examination
7. To accelerate excretion of parasites after
anthelmintic drugs have been administered
8. To reduce serum cholesterol levels (psyllium
products)
Laxatives
There are two main types of laxatives:
stimulants (chemical) and saline (liquid or
salt). They occasionally help temporary
constipation problems. However, chronic
use of laxatives, especially stimulant
laxatives is discouraged because the bowel
becomes dependent upon them. Bowel
regularity should occur without laxatives.
An occasional enema is preferrable over
the chronic use of laxatives.
Contraindications to Use
Diet
The following foods should be eaten daily in
adequate amounts
Antidiarrheals
Antidiarrheals drugs
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Antidiarrheal drugs are indicated in the following
circumstances:
1. Severe or prolonged diarrhea (>2 to 3 days), to prevent
severe fluid and electrolyte loss
2. Relatively severe diarrhea in young children and older adults.
These groups are less able to adapt to fluid and electrolyte
losses.
3. In chronic inflammatory diseases of the bowel (ulcerative
colitis and Crohn’s disease), to allow a more nearly normal
lifestyle
4. In ileostomies or surgical excision of portions of the ileum, to
decrease fluidity and volume of stool
5. HIV/AIDS-associated diarrhea
6. When specific causes of diarrhea have been determined
Contraindications to Use
Contraindications to the use of
antidiarrheal drugs include diarrhea
caused by toxic materials,
microorganisms that penetrate
intestinal mucosa (eg, pathogenic E.
coli, Salmonella, Shigella), or
antibiotic-associated colitis. In these
circumstances, antidiarrheal agents
that slow peristalsis may aggravate
and prolong diarrhea. Opiates
(morphine, codeine) usually are
contraindicated in chronic diarrhea
because of possible opiate
dependence. Difenoxin,
diphenoxylate, and loperamide are
contraindicated in children younger
than 2 years of age.