S 297995

Naldemedine (S-297995) is an orally active, peripherally acting µ-opioid receptor antagonist. Naldemedine shows potent binding affinities (IC50s = 1.15, 1.11, and 1.5 nM, repectively) and antagonist activities (IC50s= 25.57, 7.09, 16.1 nM, repectively) for recombinant human μ-, δ-, and κ- opioid receptors. Naldemedine tempers opioid-induced constipation (OIC) without compromising opioid analgesia[1].

Signaling Pathways >> GPCR/G Protein >> Opioid Receptor

Signaling Pathways >> Neuronal Signaling >> Opioid Receptor

Research Areas >> Neurological Disease

Naldemedine (S-297995) (0.001-10 mg/kg; p.o.) significantly represses the opioid-induced inhibition of small intestinal transit in rats. In the subcutaneous Morphine-induced inhibition model, the ED50s ± standard error of the mean is 0.03 ± 0.02 mg/kg for Naldemedine. Subcutaneous morphine-inhibited castor oil-induced diarrhea in rats, and pretreatment with Naldemedine 0.03-1 mg/kg significantly reverses this effect[1]. Animal Model: 6-week-old Crlj: WI male rats[1] Dosage: 0.001-10 mg/kg Administration: P.o. Result: Significantly repressed the opioid-induced inhibition of small intestinal transit in rats by subcutaneous morphine (P < 0.05 or P < 0.01 for naldemedine 0.03-10 mg/kg), and oxycodone (P < 0.01 for naldemedine 0.03-3 mg/kg).

[1]. Kanemasa T, et al. Pharmacologic effects of naldemedine, a peripherally acting μ-opioid receptor antagonist, in in vitro and in vivo models of opioid-induced constipation. Neurogastroenterol Motil. 2019;31(5):e13563.