GASTROENTEROLOGY LITERATURE REVIEW SESSION
MARCH 30, 2000
Feldman M, McMahon AT. Do
cyclooxygenase-2 inhibitors provide benefits similar to those of traditional
anti-inflammatory drugs, with less gastrointestinal toxicity? Ann Intern Med 2000;132:134-143.
1. Rofecoxib
(Vioxx)
a. does
not affect platelet aggregation, even in doses as high as 250mg/d
b. At a
dose of 25mg/d, does not affect gastric mucosal prostaglandin production
c. Is
associated with less endoscopic ulcers than treatment with ibuprofen
d. Its
use is associated with a 0.5% absolute risk reduction of confirmed clinical ulcer events
compared to traditional non-selective NSAID’s.
2. COX-2
a. Is
not present in the GI mucosa
b. May
be important in the healing of gastric ulcers
c. Inhibition
of COX-2 may abolish the gastric adaptation seen after the gastric mucosal is exposed to
repeated irritation
d. Is
important in the production of inflammation, pain and fever
True or False
1. Ten to 20% of
persons taking NSAID’s develop abdominal pain, nausea or dyspepsia, the majority of
these are found to have an ulcer when studied.
2. Severe
ulcer-related clinical events are virtually non-existent in patients treated with
selective COX-2 inhibitors.
3. COX-2 selective
inhibitors have no effects on the kidneys and can be safely used in patients with
hypertension, heart failure and ascites.
4. Celecoxib
(Celebrex) at high doses, inhibits platelet aggregation.
5. A COX-2 IC50
to COX-1 IC50 ratio of <0.1 is desirable for COX-2 selective inhibitors,
among the non-COX-2 selective inhibitors, Etodolac (Lodine) has a low (0.11) ratio.
6. Although
celecoxib is associated with a lower incidence of gastroduodenal ulceration than
non-selective NSAID’s, adverse gastrointestinal events occurred with similar
frequency as seen with non-selective NSAID’s in several studies
7. COX-1 is
expressed at a fairly constant level in most cells, including the GI tract, in contrast,
COX-2 is induced by many different stimuli.
8. COX-1
inhibition results in decrease hemostatic action by platelets.
9. COX-2
inhibitors can be safely used during pregnancy.
10. In rats, COX-2
appears to play a role in both the normal homeostasis of the stomach as well as in the
healing of gastric erosions and ulcers.
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