The U.S. Food and Drug Administration has approved Amitiza (lubiprostone) for the treatment of Irritable Bowel Syndrome with Constipation (IBS-C) in adult women aged 18 and over. There is currently no prescription drug therapy for IBS-C. With this approval, Amitiza becomes the only FDA-approved medical treatment for IBS-C available in the United States.
Irritable bowel syndrome is a disorder characterized by cramping, abdominal pain, bloating, constipation, and diarrhea. IBS causes a great deal of discomfort and distress to its sufferers. It affects at least twice as many women as men.
"For some people IBS can be quite disabling, making it difficult for them to fully participate in everyday activities," said Julie Beitz, M.D., director of the Office of Drug Evaluation III, Center for Drug Evaluation and Research, FDA. "This drug represents an important step in helping to provide medical relief from their symptoms."
The safety and efficacy of Amitiza was established in two major studies involving 1,154 patients diagnosed with IBS-C. The majority of the patients studied were women (approximately 8 percent were men). Patients enrolled in the studies were experiencing at least mild abdominal discomfort or pain that was associated with at least two of the following additional symptoms: 1) fewer than 3 spontaneous bowel movements per week (that did not result from laxative use); 2) hard stools; or 3) moderate or severe straining with bowel movements. In the studies some patients received Amitiza and others were given a placebo. More patients treated with Amitiza reported that their IBS symptoms were moderately or significantly relieved over a 12 week treatment period than patients who received placebo. The safety of long term treatment was assessed in a study in which all patients were treated with Amitiza for a duration that ranged 9 to 13 months.
The efficacy of Amitiza in men was not conclusively demonstrated for IBS-C.
Amitiza, like most prescription medications, is accompanied by some side effects. Common side effects of Amitiza include nausea, diarrhea, and abdominal pain. Other rare side effects include urinary tract infections, dry mouth, syncope (fainting), peripheral edema (swelling of the extremities), dyspnea (difficulty breathing), and heart palpitations.
Amitiza should be taken twice-a-day in 8 microgram doses with food and water. Patients and their health care professionals should periodically assess the need for continued therapy.
Amitiza is not approved for use in children and men. It is not to be administered to patients suffering from severe diarrhea or patients with known or suspected bowel obstructions. Its safety and efficacy has not been established in patients with renal or hepatic impairment, pregnant, or nursing mothers.
Amitiza is also approved for the treatment of chronic idiopathic constipation (CIC), but the dose for that indication is higher, 24 micrograms twice a day.
Amitiza is manufactured by Sucampo Pharmaceuticals, Bethesda, MD, and will be jointly marketed by Sucampo and Takeda Pharmaceuticals America, Inc., Deerfield, IL. As with all FDA-approved products, the agency will monitor Amitiza throughout its life cycle. Consumers and health care professionals are encouraged to report adverse events to the FDA.
Source: FDA, April 29, 2008