More Upsetting News About Irritable Bowel Treatment
WebMD News Archive
Following the expert panel review, the FDA did require that an
easy-to-read pamphlet explaining the risk of ischemic colitis, as well as the
risk of severe constipation, be distributed to all patients taking the drug.
The unprecedented move was ordered in August, when the FDA was aware of about
33 severe cases of both ischemic colitis and severe constipation. The FDA now
has received 21 reports of severe constipation.
While it is fair to say the additional reports have prompted
the FDA to re-evaluate the drug's benefits and risks, it is still too early to
say that Lotronex is responsible for the reported side effects or deaths or
that the new reports really reflect any increased risk to patients, an agency
spokesperson concedes. Speaking on condition of anonymity, he tells WebMD that
the federal agency expected to receive additional reports of ischemic
colitis after ordering the consumer pamphlet be distributed because of all the
media hype surrounding the issue.
"We are now trying to learn as much as we can about each of
these events," he tells WebMD, adding that some of the recent reports refer
to events that happened prior to September, when the consumer pamphlet was
For its part, Glaxo Wellcome maintains that the risk of
ischemic colitis is minimal and probably not associated with Lotronex. When
asked whether there is a possible association, Eric Carter, MD, PhD, director
of Glaxo Wellcome's U.S. gastrointestinal drug division, says that after
extensive animal and human studies of the drug, the researchers there could not
find a mechanism to explain the reports of ischemic colitis.
The majority of events have been temporary and reversible, with
less than half of the patients requiring hospitalization, Carter notes. This
type of ischemic colitis also has been associated with a number of other
medications, including oral contraceptives, he notes.
The reports, Carter adds, may simply reflect the true incidence
of ischemic colitis in the U.S. Currently, the estimated incidence is about
three out of every 10,000 people, but the temporary ischemic colitis reported
in association with Lotronex use "probably occurs more frequently [in the
general public] than is recognized," he tells WebMD.