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.

MOVANTIK (naloxegol) is a peripherally-acting mu-opioid receptor antagonist indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic noncancer pain. It is being investigated for the treatment of constipation as a side effect of prescription opioid pain medicines.

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.

Methylnaltrexone bromide, (17s)- (methylnaltrexone bromide), a quaternary amine of the pure narcotic antagonist naltrexone, is a peripherally-acting selective mu-opioid antagonist. Methylnaltrexone antagonizes opioid binding at mu-opioid receptors, half-maximal inhibitory concentration (IC50) of 70 nM. It has a relatively lower affinity for κ-opioid receptors (IC50 575 nM), and it does not interact with δ-receptors or orphanin FQ receptors. Approved by FDA in the United States under the trade name Relistor, methylnaltrexone bromide is indicated for the treatment of opioid-induced constipation in patients with advanced illness who are receiving palliative care, when the response to laxative therapy has not been sufficient. Restricted ability to cross the blood-brain barrier allows methylnaltrexone bromide to function in tissues such as the gastrointestinal tract, decreasing the constipating effects of opioids without impacting opioid-mediated analgesic effects on the central nervous system.

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.

MOVANTIK (naloxegol) is a peripherally-acting mu-opioid receptor antagonist indicated for the treatment of opioid-induced constipation (OIC) in adult patients with chronic noncancer pain. It is being investigated for the treatment of constipation as a side effect of prescription opioid pain medicines.

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.

Methylnaltrexone bromide, (17s)- (methylnaltrexone bromide), a quaternary amine of the pure narcotic antagonist naltrexone, is a peripherally-acting selective mu-opioid antagonist. Methylnaltrexone antagonizes opioid binding at mu-opioid receptors, half-maximal inhibitory concentration (IC50) of 70 nM. It has a relatively lower affinity for κ-opioid receptors (IC50 575 nM), and it does not interact with δ-receptors or orphanin FQ receptors. Approved by FDA in the United States under the trade name Relistor, methylnaltrexone bromide is indicated for the treatment of opioid-induced constipation in patients with advanced illness who are receiving palliative care, when the response to laxative therapy has not been sufficient. Restricted ability to cross the blood-brain barrier allows methylnaltrexone bromide to function in tissues such as the gastrointestinal tract, decreasing the constipating effects of opioids without impacting opioid-mediated analgesic effects on the central nervous system.