Relistor Oral Tablets for Opioid-Induced Constipation
The Relistor oral tablets are now available in the U.S. market. The injection formulation of Relistor has been approved and available in the market since 2008. The oral formulation of Relistor was approved by FDA this July for the treatment of opioid-induced constipation (OIC) in adults with chronic non-cancer pain.
Relistor is a peripherally-acting, selective mu-opioid receptor antagonist with restricted central nervous system penetration. The FDA approval on this oral formulation was based on a randomized, double-blind, phase 3 trial where once-daily dosing of 450 mg Relistor was compared to placebo in adults with chronic non-cancer pain. Overall, the efficacy of the treatment was similar to that reported in clinical studies of subcutaneous injection of Relistor and the overall safety profile was also similar to that in patients taking placebo. As Relistor subcutaneous injection, the oral tablet is contraindicated in patients with known or suspected gastrointestinal obstruction and patients at increased risk of recurrent obstruction, due to the potential for gastrointestinal perforation.
The recommended dose for oral Relistor is 450 mg once daily by taking three 150-mg tablets. The dose needs to be adjusted to 150 mg once daily in patients with renal impairment (creatinine clearance less than 60 ml/minute) and moderate or severe hepatic function impairment. The tablets should be taken with water on an empty stomach at least 30 minutes before the first meal of the day as food may impact the absorption.
Relistor is not a first-line drug for treatment of constipation in hospice patients; however, it may be appropriate for the patient with severe opioid induced constipation who has not responded to traditional laxative therapy such as senna, bisacodyl or osmotic laxatives. The approximate cost for the oral formulation for a 2-week supply is $840, which is less expensive than the injection ($1680).
Relistor® [package insert]. Bridgewater, NJ: Valeant Pharmaceuticals North America LLC; 2016