Naldemedine (Symproic®) is an orally active µ-opioid receptor antagonist being developed by Shionogi & Co., Ltd. that has been approved in the USA and Japan for the treatment of opioid-induced constipation. The drug inhibits peripheral µ-opioid receptors such as those present in the gastrointestinal tract and has minimal or no effect on central opioid activity. This article summarizes the milestones in the development of naldemedine leading to its first global approval in the USA for the treatment of opioid-induced constipation in patients with chronic non-cancer pain.