Drug Therapy For IBS Essay Jordan is a 35-year-old woman who presents with intermittent diarrhea with cramping that is relieved by defecation. The diarrhea is not bloody or accompanied by nausea and vomiting. Review of past medical history includes some childhood “stomach issues”, HTN, and a recent cholecystectomy. She works in the environmental department of a large hotel. . She denies alcohol and cigarette.Drug Therapy For IBS Essay

Drug Therapy For IBS Essay Jordan is a 35-year-old woman who presents with intermittent diarrhea with cramping that is relieved by defecation. The diarrhea is not bloody or accompanied by nausea and vomiting. Review of past medical history includes some childhood “stomach issues”, HTN, and a recent cholecystectomy. She works in the environmental department of a large hotel. . She denies alcohol and cigarette.Drug Therapy For IBS Essay

Tricyclic Antidepressants (TCA)
As with the antispasmodics, the reviews assessing the
efficacy of TCA use for relieving IBS-related abdominal
pain have lead to inconsistent conclusions.8, 11, 12, 14 A
physiological study showed that a TCA (imipramine)
prolonged intestinal transit time.23 The anticholinergic
properties of TCAs, along with this finding, support the
use of these agents for treating diarrhea. Therefore,
patients suffering from IBS-related abdominal pain may
benefit from a TCA when a diarrhea component is also
present, or when indicated for a co-morbid mental health
disorder. Avoid using in patients with constipation, as
TCAs may provoke or aggravate constipation.2, 10, 12
Selective Serotonin Reuptake Inhibitor (SSRI)
No systematic reviews or meta-analysis, for this
indication, have been conducted with the SSRIs, largely
due to the small number of trials involving these agents.
Although the clinical significance has yet to be
determined, the above mentioned physiological study also
showed that a SSRI (paroxetine) accelerated intestinal
transit time – thus suggesting that SSRIs would be more
suited for treating constipation. 23 A study involving
fluoxetine in IBS patients suffering from pain and
constipation (ROME II criteria) strengthened this notion.
In this trial, 44 patients (61% , mean age 34.9 [±10
years]) were randomized to fluoxetine 20mg po OD x 12
weeks or placebo, in a tertiary setting. By week 4,
abdominal discomfort, bloating, hard stool consistency,
frequency of bowel movements <3 times a week and
change in bowel habit were all significantly improved in
the fluoxetine group (p<0.05 for each). This effect
continued to week 12. Four weeks after the study
medications were discontinued, all of the above endpoints
– except change in bowel habit, were still significantly
less in the fluoxetine group.Drug Therapy For IBS Essay
In other words, in patients suffering from IBS-related
abdominal pain and constipation may benefit from a
SSRI. The SSRIs have also been investigated in patients
suffering from diarrhea-predominate IBS. However, until
additional evidence is available, reserve this class of
antidepressants for co-morbid mental health disorders in
these patients.
Only three SSRI antidepressants have been studied in IBS
patients to date – fluoxetine PROZAC, paroxetine
PAXIL and citalopram CELEXA.
22, 24, 25 {For studied
doses in IBS, see Comparison Chart.}
Abdominal Bloating
Alleviating constipation, if present, may help reduce
bloating. If using fiber supplementation to treat
constipation, use cautiously as fibre may worsen
bloating.5
Fluoxetine has been shown to relieve
constipation, abdominal pain and bloating in patients
suffering from constipation-predominant IBS and
associated pain.24 Otherwise, medications are not useful
for bloating.
Herbal Medications, Probiotics & Alternatives
A Cochrane review assessed the effectiveness and safety
of Chinese herbal medicines in IBS patients, but
concluded that there is limited evidence to suggest using
herbal agents at this time.26 Currently, there is
insufficient data to recommend any probiotics for IBS.
Hypnosis, yoga, meditation, tai chi & acupuncture has no
or limited evidence, but anecdotal cases of success.
Cognitive behavioral therapy, standard psychotherapy and
hypnotherapy 32 may help selected IBS patients.
Agents on the Horizon
Asimadoline (a peripheral kappa-opioid agonist),
cilansetron (competitive type 3 serotonin 5-HT3 receptor
antagonist), renzapride (a novel benzamide related to
cisapride) & talnetant (a neurokinin-3 receptor-specific
antagonists) are four examples of potentially promising
agents for IBS.Drug Therapy For IBS Essay

The etiology of IBS has not yet been identified. Examination of the large and small bowels has revealed altered GI motility. This delays meal transit in patients who report constipation but accelerates transport in patients who report diarrhea. Patients with IBS also have visceral hyperalgesia. Microscopically, some bacterial overgrowth and microscopic inflammation has been identified in patients who have IBS.8

In addition, IBS is associated with psychopathology. Patients with IBS tend to have a higher incidence of anxiety disorder, catastrophizing, major depression, panic disorder, and somatoform disorders than the general population.1,9 A major concern i