What is "naldemedine"

Naldemedine ( INN, USAN; S-297,995) is a peripherally- selective μ-opioid receptor antagonist under development by Shionogi for the treatment of opioid-induced adverse effects including constipation, nausea, and vomiting. Clinical studies have thus far found it to possess statistically significant effectiveness for these indications and to be generally well-tolerated with predominantly mild to moderate gastrointestinal side effects. No effects indicative of central opioid withdrawal or impact on the analgesic or mydriatic effects of co-administered opioids have been observed. As of July 2014, naldemedine is in phase III clinical trials in the United States and Japan.