examined 18 randomized controlled trials of which only three included

Examined 18 randomized controlled trials of which

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examined 18 randomized controlled trials, of which only three included dicyclomine and hyoscyamine, but concluded the trials were of suboptimal quality based on study design with inadequate duration of treatment. With only one of those previously mentioned three studies demonstrating a statistically significant improvement in global IBS symptoms and abdominal pain [88] and more frequent anticholinergic side effects versus placebo (69% vs 16%), it is easy to understand why insufficient data ex - ist about antispasmodics. Even though the antispasmodic medications have not demonstrated an overwhelming statistically significant advantage [84] , it is common practice in the United States to utilize these agents. The anticho- linergic effects, including constipation, dry mouth, visual disturbances, and urinary retention, can lead to discon- tinuation of these medications. These medications can be given as an oral formulation or a sublingual tablet, and be dosed on an as-needed or regular basis. Many patients benefit by taking the medication before meals. If known exacerbating factors such as a particular diet or stress are anticipated, these medications can be given as a pro- phylactic measure. It has also been noted that medicines such as dicyclomine can lose effectiveness with chronic use; therefore, it may be best employed on an as-needed basis [7] . Given the potential side effect of constipation, these medications should be used cautiously in IBS with constipation predominating [43] . EFFECTIVENESS OF ANTIDEPRESSANT AGENTS IN THE MANAGEMENT OF IRRITABLE BOWEL SYNDROME Tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs) are more effective than pla - cebo at relieving global IBS symptoms, and appear to re- duce abdominal pain. There are limited data on the safety and tolerability of these agents in patients with IBS. Nine trials were identified that tested TCAs in various doses for IBS. TCAs clearly were superior to placebo (NNT = 4, 95%CI: 3-6) [43] . There is no convincing evidence that the dose needed has to be in the antidepressant range, and most trials tested low-dose TCAs. In two of the trials, ab- dominal pain was the primary endpoint and a significant benefit was observed. Five trials that assessed SSRIs also showed a benefit in IBS over placebo (NNT = 3.5) [43] . Theoretically, SSRIs should be of most benefit for IBS-C, whereas TCAs should be of greatest benefit for IBS-D because of their differential effects on intestinal transit time, but there is a lack of available data from the clinical trials to assess this clinical impression. The safety of us- ing antidepressants in IBS remains poorly documented, although data suggest that the SSRIs are tolerated bet - ter than the TCAs. No data on the efficacy of SSRIs or other new antidepressant drug classes are available in the literature [43] .
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