Let's move on to irritable bowel syndrome, or irritable bowel
disease. I find it sometimes the two diseases to be indistinguishable,
so we'll categorize or classify all of the drugs into one
slide here. So these IBS type syndromes,
can be including the antispasmodics, the
serotonin inhibitors, and the chloride channel activators.
Let's start off with the antispasmodics. So these agents are
used to relieve abdominal pain, in patients who we believe
are having spasm of the bowel for no apparent reason.
I'm not entirely convinced of their efficacy.
However, remember that this particular disease is very very
hard to treat and we often are throwing the kitchen sink
at the patients to try and help treat them.
Another type of treatment are serotonin inhibitors.
So, the serotonin 3 antagonists, tend to be used in women,
with severe IBS with diarrhoea. Now IBS is divided into IBS
diarrhoea and IBS constipation, and we obviously are using
different approaches for each of those categories of IBS. The
nice thing about these serotonin 3 receptor antagonists,
is that they also have some anti-emetic effects. Now
unfortunately, the anti-emetic effects may be linked
to ischemic colitis. We are not entirely sure, so you have
to be careful with these medications.
These agents are restricted to GI specialists with experience
in this area. So, as a person who does not have a lot of
experience with these agent, I will not prescribe it. I will
refer this on, so that a specialist can use it.
For this reason, it probably won't show up on your exam,
other than to let you know, today that this agent is out there.
Don't spend too much time memorizing it for your exam.
Let's move on to the chloride channel activators. Now these
activate type 2 chloride channels in the small intestine,
and they are approved for women with severe IBS
in constipation. Other agents are acting directly
the cyclic AMP production, and they also activate the
type 2 chloride channel. And for this reason
they are placed in the same drug category.