Naldemedine (Symproic) is an opioid antagonist indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic non-cancer pain. Naldemedine is an opioid antagonist with binding affinities for mu-, delta-, and kappa-opioid receptors. Naldemedine functions as a peripherally-acting mu-opioid receptor antagonist in tissues such as the gastrointestinal tract, thereby decreasing the constipating effects of opioids. Naldemedine is a derivative of naltrexone to which a side chain has been added that increases the molecular weight and the polar surface area, thereby reducing its ability to cross the blood-brain barrier (BBB). Naldemedine is also a substrate of the P-glycoprotein (P-gp) efflux transporter. Based on these properties, the CNS penetration of naldemedine is expected to be negligible at the recommended dose levels, limiting the potential for interference with centrally-mediated opioid analgesia. Naldemedine was approved in 2017 in both the US and Japan for the treatment of Opioid-induced Constipation.

Eluxadoline, an orally active mixed μ opioid receptor (μOR) agonist δ opioid receptor (δOR) antagonist. Eluxadoline normalizes gastrointestinal (GI) transit and defecation under conditions of novel environment stress or post-inflammatory altered GI function. Allergan (previously Actavis) is developing eluxadoline for the treatment of diarrhoea-predominant irritable bowel syndrome. The agent was originated by Janssen Pharmaceutica. Eluxadoline has been launched in the US under trade name VIBERZI (eluxadoline) tablets, while is at the preregistration stage in the EU.

Tapentadol is the first US FDA-approved centrally acting analgesic having both μ-opioid receptor agonist and noradrenaline (norepinephrine) reuptake inhibition activity with minimal serotonin reuptake inhibition. Tapentadol is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate, neuropathic pain associated with diabetic peripheral neuropathy (DPN) severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.

Tapentadol is the first US FDA-approved centrally acting analgesic having both μ-opioid receptor agonist and noradrenaline (norepinephrine) reuptake inhibition activity with minimal serotonin reuptake inhibition. Tapentadol is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate, neuropathic pain associated with diabetic peripheral neuropathy (DPN) severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.

Tapentadol is the first US FDA-approved centrally acting analgesic having both μ-opioid receptor agonist and noradrenaline (norepinephrine) reuptake inhibition activity with minimal serotonin reuptake inhibition. Tapentadol is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate, neuropathic pain associated with diabetic peripheral neuropathy (DPN) severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.

Tapentadol is the first US FDA-approved centrally acting analgesic having both μ-opioid receptor agonist and noradrenaline (norepinephrine) reuptake inhibition activity with minimal serotonin reuptake inhibition. Tapentadol is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate, neuropathic pain associated with diabetic peripheral neuropathy (DPN) severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.

Tapentadol is the first US FDA-approved centrally acting analgesic having both μ-opioid receptor agonist and noradrenaline (norepinephrine) reuptake inhibition activity with minimal serotonin reuptake inhibition. Tapentadol is indicated for the management of pain severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate, neuropathic pain associated with diabetic peripheral neuropathy (DPN) severe enough to require daily, around-the-clock, long-term opioid treatment and for which alternative treatment options are inadequate.

Alvimopan (LY246736, ADL 8-2698, trade name Entereg) is a potent, peripherally selective mu-opioid receptor antagonist. Alvimopan was developed by Adolor Corporation (now Cubist Pharmaceuticals) and GlaxoSmithKline for the treatment of postoperative ileus. Postoperative ileus is the impairment of gastrointestinal motility after intra-abdominal surgery or other non-abdominal surgeries. This may potentially delay gastrointestinal recovery and hospital discharge until its resolution. Morphine and other mu-opioid receptor agonists are universally used for the treatment of acute postsurgical pain; however, they are known to have an inhibitory effect on gastrointestinal motility and may prolong the duration of postoperative ileus. Following oral administration, alvimopan antagonizes the peripheral effects of opioids on gastrointestinal motility and secretion by competitively binding to gastrointestinal tract mu-opioid receptors.

Methylnaltrexone, is a peripherally acting μ-opioid receptor antagonist that acts on the gastrointestinal tract to inhibit the opioid-induced decrease in gastric motility and transit time. It is used to treat opiate-induced constipation in adults with chronic non-cancer pain and in adults with advanced illness who are receiving palliative care.

Alvimopan (LY246736, ADL 8-2698, trade name Entereg) is a potent, peripherally selective mu-opioid receptor antagonist. Alvimopan was developed by Adolor Corporation (now Cubist Pharmaceuticals) and GlaxoSmithKline for the treatment of postoperative ileus. Postoperative ileus is the impairment of gastrointestinal motility after intra-abdominal surgery or other non-abdominal surgeries. This may potentially delay gastrointestinal recovery and hospital discharge until its resolution. Morphine and other mu-opioid receptor agonists are universally used for the treatment of acute postsurgical pain; however, they are known to have an inhibitory effect on gastrointestinal motility and may prolong the duration of postoperative ileus. Following oral administration, alvimopan antagonizes the peripheral effects of opioids on gastrointestinal motility and secretion by competitively binding to gastrointestinal tract mu-opioid receptors.