Indacaterol-induced severe constipation and abdominal pain: is there a role for colonic β3-adrenoceptors?

Indacaterol is an ultra-long-acting β2-adrenoceptor agonist that is indicated for the maintenance treatment of chronic obstructive pulmonary disease. We present a patient with severe chronic constipation and abdominal pain most probably induced by this medicament. Symptoms rapidly disappeared within 2 days after the drug withdrawal. As far as we know, no reports describing severe chronic constipation associated with indacaterol have been published. The Naranjo algorithm score and the Edwards and Aronson scale for causality assessment of suspected adverse drug reactions indicated a probable relationship between indacaterol use and constipation. Indacaterol-induced constipation is an unusual event that could be accounted for the high intrinsic activity of the drug on colonic β3-adrenoreceptors, resulting in an inhibitory control of smooth muscle function and intestinal secretion. Clinicians should monitor such a possibility when prescribing this drug and maybe avoid its use in patients with a history of difficult bowel evacuation.