FDA approved Ironwood Pharmaceuticals’ capsule drug Linzess (linaclotide) to treat chronic idiopathic constipation and irritable bowel syndrome with constipation (IBS-C) in adults.
Linzess is taken once daily on an empty stomach, at least 30 minutes before the first meal of the day. Linzess is designed to help relieve constipation by making bowel movements occur more often, while for IBS-C it may also help ease abdominal pain.
Approval for IBS-C was based on two double-blind studies in which a total 1,604 patients were randomly assigned to take 290 mcg of Linzess or a placebo for at least 12 weeks. Results showed Linzess was more effective in reducing abdominal pain and increasing the number of complete spontaneous bowel movements compared with placebo.
Approval for chronic idiopathic constipation also was based on two double-blind studies in which a total 1,272 patients were randomly assigned to take Linzess at doses of 145 mcg or 290 mcg or a placebo for 12 weeks. Patients taking Linzess experienced more complete spontaneous bowel movements than those taking placebo. The 290 mcg dose is not approved for chronic constipation because studies indicated it was no more effective than the 145 mcg dose.
Linzess was approved with a Boxed Warning to patients and health care professionals that the drug should not be used in patients 16 years of age and younger. Diarrhea was the most common side effect reported during the clinical studies.