gastric acid secretion and concentration. Histamine2 blockers also cause head-
aches, dizziness, constipation, pruritus, skin rash, gynecomastia, decreased libido,
and impotence. Examples include Cimetidene (Tagamet) Famotidene (Pepsid)
Ranitidine (Zantac).
Proton pump inhibitors
Proton pump inhibitors (gastric acid secretion inhibitors, gastric acid pump
inhibitors) inhibit gastric acid secretion 90% greater than the H2 blockers
because they block the final step of acid production. Both omeprazole (Prilosec)
and lansoprazole (Prevacid) are proton pump inhibitors used for the treatment of
peptic ulcers and GERD. Those with hepatic impairment should take these drugs
with caution and have liver enzymes monitored regularly.
Pepsin inhibitor
Pepsin inhibitors such as sucralfate (Carafate) are mucosal protective drugs that
are non-absorbable and combine with protein to form a viscous substance that
covers the ulcer. This protects it from acid and pepsin. Pepsin inhibitors do not
neutralize acid or decrease acid secretions.
Prostaglandin E1 analogue
Prostaglandin analogue antiulcer drugs such as misoprostol (Cytotec), prevents
and treats peptic ulcers by suppressing gastric acid secretion and increasing
cytoprotectivemucus in the GI tract. Prostaglandin analogue also moderately
decreases pepsin secretion. Prostaglandin analogue is ideal for patients who have
gastric distress from taking NSAIDS such as aspirin or indomethacin.
Prostaglandin analogue should not be taken during pregnancy and by any
women of childbearing age.
Gastrointestinal stimulants
Gastrointestinal stimulants are used to treat nocturnal heartburn caused by GERD
and primarily prescribed for patients who do not respond to other drugs or non-
drug therapy. Gastrointestinal stimulants increase gastric emptying time prevent-
ing acid reflux into the esophagus. Gastrointestinal stimulants also enhance the
release of acetylcholine at the mysenteric plexus. Cisapride (Propulsid) is an
example of a gastrointestinal stimulant.
Gastrointestinal stimulants should not be used for patients who have cardiac
dysrhythmias especially ventricular tachycardia, ventricular flutter, or fibrillation.
CHAPTER 18 Gastrointestinal System^343