Constella (linaclotide) is a new drug approved for symptomatic treatment of adults with moderate to severe irritable bowel syndrome with constipation. The mechanism of action is an increased secretion in the bowel, a possible analgesic effect and a faster colonic transit time. The systemic absorption is minimal and the adverse events are therefore practically limited to mild to moderate diarrhea, which is seen in 20 % of the treated patients. During the studies, about 5 % stopped treatment with linaclotide because of diarrhea. Altogether, 33-55 % of the patients had a clinically relevant response to the treatment with linaclotide, however, a considerable effect was also seen in 14-42 % of the patients in the placebo group. Half of the patients did not respond sufficiently to the treatment. Patients were included in the clinical studies based on the Rome II criteria for irritable bowel syndrome. These are, presumably, more restrictive than the diagnostic threshold for colon irritable in general practice. The indication should be reassessed after four weeks of treatment with Constella.
It is the opinion of IRF that the primary treatment of irritable bowel syndrome should remain non-pharmacological focusing on a high fiber diet, good bowel habits and psycho-social factors. Constella may be an option for some patients, however, the high placebo effect, non-response rate and price should be kept in mind.
Constella was marketed April 29th 2013. It is currently possible to apply for single reimbursement.