Pharmacotherapeutic Tx for IBS: Reviewing the Evidence
the MPR take:
Due to the multifactorial pathophysiologies responsible for the symptoms of irritable bowel syndrome (IBS), treatment requires knowledge of the distinct properties of the current approved medications along with the individual patient profile. Because of a lack of adequate diagnostic measures and the heterogeneity of the IBS population, therapy is mainly focused on controlling symptoms rather than reversing underlying putative pathophysiological disturbances. A review in the journal Drugs compared outcomes of published clinical trials on pharmacological agents for IBS and its subtypes IBS with diarrhea (IBS-D), IBS with constipation (IBS-C), mixed IBS (IBS-M), and un-subtyped IBS (IBS-U). While psyllium is commonly used as an initial treatment for IBS-C, it has been shown to improve symptoms in all IBS subtypes. As the availability and formulations of antispasmodics vary, the evidence for their efficacy in treating IBS pain is generally limited or poor. Meta-analyses have found strong support for the use of low-dose antidepressants in treating IBS in general, although specific subtypes have not been studied in these assessments. There is no current consensus on the use of probiotics due to variations in study designs, but they may be beneficial in improving IBS symptoms in a subset of patients. In two studies, melatonin was beneficial in reducing pain scores and other IBS symptoms regardless of its effects on sleep. Promising new treatments for IBS pain include glutamate, pregabalin, and histamine-1 receptor antagonists along with other agents already indicated for use in other gastrointestinal disorders like 5-HT4 receptor antagonists and bile acid modulators.
Treatment of irritable bowel syndrome (IBS) is challenging for both primary care physicians and gastroenterologists because of the heterogeneity of the patient population and the multifactorial pathophysiologies responsible for the symptoms in IBS.