The ABCs of IBS

I’ve been thinking about irritable bowel syndrome (IBS) lately.

I believe it all started with the memorable advertisement for the drug Xifaxan by Valeant Pharmaceuticals. In the ads, an intestinal-shaped character dubbed “gut guy” urgently runs to the bathroom and then panics when he sees a long line. Some of your IBS patients can probably relate.

IBS treatments actually have a pretty interesting history. First, there were no specific treatments, and then new treatments were approved and either removed from the market or restricted. Alosetron (Lotronex) was approved in 2000 for IBS with diarrhea (IBS-D), voluntarily withdrawn from the market by the manufacturer, and then made available under a prescribing program. Tegaserod (Zelnorm) was approved in 2002 for IBS with constipation (IBS-C) and then later removed from the market. I can only imagine the frustration of an IBS patient at the time of this upheaval.

Today, we have a variety of FDA-approved treatments for IBS, both IBS-C and IBS-D (see table).

According to the 2014 American Gastroenterological Association Guideline on the Pharmacological Management of IBS, the suggested treatment options for IBS-C are linaclotide (Linzess), lubiprostone (Amitiza) and polyethylene glycol (PEG) laxatives. For IBS-D, the guideline suggested rifaximin (Xifaxan), Lotronex, loperamide, tricyclic antidepressants, selective serotonin reuptake inhibitors, and antispasmodics.

The 2014 American College of Gastroenterology monograph on the management of irritable bowel syndrome and chronic idiopathic constipation reviewed a variety of therapeutic options, both prescription and OTC.

This review found that the vast majority of treatment options are either ineffective or have insufficient evidence of efficacy. While many treatments are available, the only recommended therapies that had “strong evidence” of advantage over placebo of at least “moderate” quality of evidence are Linzess and Amitiza.

I hope that this review will assist you in your conversations with your patients. IBS can be an embarrassing, difficult-to-treat condition. Listening to your IBS patients with empathy and concern will go a long way toward helping them improve their health.

Drug

FDA Indication(s)

Contraindication(s)

CONSTIPATION

Lubiprostone (Amitiza)

• Irritable bowel syndrome with constipation (IBS-C)
• Chronic idiopathic constipation (CIC)
• Opioid-induced constipation

• Known or suspected mechanical gastrointestinal obstruction

Linaclotide (Linzess)

• IBS-C
• CIC

• Pediatric patients aged <6 years
• Known or suspected mechanical gastrointestinal obstruction

DIARRHEA

Alosetron (Lotronex)

Lotronex is indicated only for women with severe diarrhea-predominant IBS who:

• Have chronic IBS symptoms (generally lasting 6 months or longer)
• Had anatomic or biochemical abnormalities of the gastrointestinal tract excluded
• Did not respond adequately to conventional therapy

Severe IBS includes diarrhea and 1 or more of the following:

• Frequent and severe abdominal pain/discomfort
• Frequent bowel urgency or fecal incontinence
• Disability or restriction of daily activities due to IBS

• Chronic or severe constipation or sequelae from constipation
• Intestinal obstruction, stricture, toxic megacolon, gastrointestinal perforation, and/or adhesions
• Ischemic colitis
• Impaired intestinal circulation, thrombophlebitis, or hypercoagulable state
• Crohn’s disease or ulcerative colitis
• Diverticulitis
• Severe hepatic impairment

Eluxadoline (Viberzi)

• IBS-Diarrhea (IBS-D)

• Known or suspected biliary duct obstruction; or sphincter of Oddi disease or dysfunction
• Alcoholism, alcohol abuse, or alcohol addiction, or a patient who drinks more than 3 alcoholic beverages per day
• History of pancreatitis, or structural diseases of the pancreas, including known or suspected pancreatic duct obstruction
• Severe hepatic impairment (Child-Pugh Class C)
• History of chronic or severe constipation or sequelae from constipation, or known or suspected mechanical gastrointestinal obstruction

Rifaximin (Xifaxan)

• IBS-D
• Travelers’ diarrhea
• Hepatic encephalopathy

• Hypersensitivity

References

1. Ford AC, Moayyedi P, Lacy BE, et al. American College of Gastroenterology monograph on the management of irritable bowel syndrome and chronic idiopathic constipation. Am J Gastroenterol. 2014;109 Suppl 1:S2-26.

2. Weinberg DS, Smalley W, Heidelbaugh JJ, Sultan S. American Gastroenterological

Association Institute Guideline on the pharmacological management of irritable bowel

syndrome. Gastroenterology. 2014;147(5):1146-8.

3. Amitiza [package insert]. Deerfield, IL: Takeda Pharmaceuticals America, Inc.; April 2013.

4. Linzess [package insert]. Cincinnati, OH: Forest Pharmaceuticals, Inc.; November 2015.

5. Lotronex [package insert]. San Diego, CA: Prometheus Laboratories Inc.; August 2015.

6. Viberzi [package insert]. Parsippany, NJ: Actavis Pharma, Inc; May 2015.

7. Xifaxan [package insert]. Bridgewater, NJ: Salix Pharmaceuticals; November 2015.