Rifaximin (Xifaxan – Salix), a minimally absorbed oral antibiotic approved previously to treat travelers' diarrhea and to reduce the risk of recurrent hepatic encephalopathy, has now been approved by the FDA for treatment of irritable bowel syndrome with diarrhea (IBS-D). Eluxadoline (Viberzi – Actavis), a mu-opioid receptor agonist, was also recently approved for IBS-D and will be reviewed in a future issue.

Rifaximin (Xifaxan - Salix), a non-absorbed oral antibiotic derived from rifampin (Rifadin, and others), has been approved by the FDA for treatment of travelers' diarrhea caused by noninvasive strains of Escherichia coli in patients 12 years of age or older. It has been available in Europe since 1987.

The FDA has approved rifamycin (Aemcolo – Cosmo/ Aries), a minimally absorbed oral antibiotic, for treatment of adults with travelers' diarrhea (TD) caused by noninvasive strains of Escherichia coli. It is not recommended for treatment of diarrhea that is complicated by fever and/or bloody stools. Topical and injectable formulations of rifamycin have been used in Europe for other indications for many years.

Erlotinib (Tarceva) is the second oral epidermal growth factor receptor (EGFR) inhibitor to become available in the US for treatment of advanced refractory NSCLC. In clinical trials, erlotinib produced a response rate of only 8.9%, but increased median survival from 4.7 to 6.7 months. Patients who had never smoked and those with EGFR-positive tumors survived longer. Erlotinib is generally well tolerated; diarrhea and rash are the most common adverse effects.

The most common cause of travelers' diarrhea, usually a self-limited illness without fever lasting several days, is infection with noninvasive enterotoxigenic (ETEC) or enteroaggregative (EAEC) strains of Escherichia coli. Campylobacter, Shigella, Salmonella, Aeromonas, viruses and parasites are less common.

Irinotecan hydrochloride (Camptosar - Pharmacia & Upjohn; formerly CPT-11) has been approved by the US Food and Drug Administration for treatment of metastatic colorectal cancer refractory to other drugs including fluorouracil (5-FU; Adrucil and others).

A reader asked whether healthcare providers should avoid prescribing the angiotensin receptor blocker (ARB) olmesartan medoxomil (Benicar, and others) because it can cause severe GI adverse effects.In 2013, the FDA warned that olmesartan can cause sprue-like enteropathy, a condition characterized by intestinal villous atrophy, severe chronic diarrhea, and significant unintended weight loss. The warning was based on 23 cases of serious sprue-like enteropathy associated with use of olmesartan, some occurring years after starting the drug. All patients improved after stopping olmesartan; 10 had a...

The oral tyrosine kinase inhibitor neratinib (Nerlynx – Puma Biotechnology) has been approved by the FDA for use in combination with capecitabine (Xeloda, and generics) for treatment of advanced or metastatic human epidermal growth factor receptor 2 (HER2)-positive breast cancer in adults who received ≥2 prior anti-HER2-based regimens for metastatic disease. It was previously approved for use as monotherapy for extended adjuvant treatment of adults with early-stage, HER2-positive breast cancer following adjuvant trastuzumab (Herceptin)-based therapy. HER2 is overexpressed in...

Irritable bowel syndrome (IBS) is a common disorder characterized by recurrent abdominal pain and altered bowel habits, often accompanied by bloating. IBS is classified by its predominant bowel symptom: constipation (IBS-C), diarrhea (IBS-D), mixed type (IBS-M), or unclassified (IBS-U). Since the exact cause of IBS is unknown, the goal of treatment is symptom control. Some over-the-counter (OTC) products and prescription drugs for IBS are listed in Tables 1-4. The safety of these drugs during pregnancy and lactation is described in Table 5 (online only).

Patients who receive pretravel advice can reduce their risk for many travel-related conditions. Vaccines recommended for travelers are reviewed in a separate issue.