The prescribing information for Amitiza (lubiprostone capsules; Sucampo and Takeda), Movantik (naloxegol tablets; AstraZeneca), Relistor Tablets (methylnaltrexone bromide; Valeant), Relistor Injection (methylnaltrexone bromide; Valeant), and Symproic (naldemedine tablets; Shionogi and Purdue) has been updated to provide clarification of the opioid-induced constipation (OIC) indication.1
Specifically, the labeling now states that these agents are indicated for the treatment of OIC in adult patients with chronic non-cancer pain, including patients with chronic pain related to prior cancer or its treatment who do not require frequent (eg, weekly) opioid dosage escalation. In addition, the Relistor Injection indication now states that OIC treatment is indicated for patients with advanced illness or pain caused by active cancer who require opioid dosage escalation for palliative care.
Amitiza is a locally acting chloride channel activator that enhances a chloride-rich intestinal fluid secretion without altering sodium and potassium concentrations in the serum. Lubiprostone, via activation of the apical CIC-2 channels in intestinal epithelial cells, bypasses the antisecretory action of opiates that results from suppression of secretomotor neuron excitability.
Movantik is an antagonist of opioid binding at the mu-opioid receptor. When administered at the recommended dose levels, naloxegol functions as a peripherally acting mu-opioid receptor antagonist in tissues such as the gastrointestinal (GI) tract, thereby decreasing the constipating effects of opioids.
Relistor functions as a peripherally-acting mu-opioid receptor antagonist in tissues such as the GI tract, thereby decreasing the constipating effects of the opioids without impacting opioid-mediated analgesic effects on the central nervous system.
Symproic is an opioid antagonist with binding affinities for mu-, delta-, and kappa-opioid receptors. Naldemedine functions as a peripherally acting mu-opiod receptor antagonist in tissues such as the GI tract, thereby decreasing the constipating effects of opioids. Symproic has been scheduled as a CII controlled substance due to its structural relation to naltrexone, however the U.S. Drug Enforcement Administration (DEA) recently proposed to deschedule naldemedine.
- FDA Approved Drug Products. US Food and Drug Administration. Updated August 2017. Available at: https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=reportsSearch.process. Accessed on August 14, 2017.
This article originally appeared on MPR