On May 29, the official website of the National Medical Products Administration (NMPA) showed that Naldemedine (generic name: Naldemedine tosylate tablets, trade name: Symproic® ) was approved for marketing for the treatment of opioid-induced constipation (OIC) in adults [ 1] . The approval of this innovative drug will provide patients suffering from OIC with a new treatment option to improve their quality of life (QOL) and promote the overall improvement of the level of supportive care for tumors in China. In January 2025, Chia Tai Tianqing Pharmaceutical Group, a core enterprise of China Biopharmaceutical (1177.HK), signed an agreement with Shionogi to obtain the exclusive marketing rights of Naldemedine in mainland China.

Nadecamide is the world's first approved oral selective peripheral μ-opioid receptor antagonist. By blocking the binding of opioids to μ receptors in the intestine, it directly restores the normal peristaltic rhythm and intestinal fluid secretion function, thus reversing the pathological process of OIC from the root [2] . Currently, nadecamide has been approved for marketing in China (including Hong Kong, Macao and Taiwan), the United States, the European Union, the United Kingdom and Japan, and has been recommended for the treatment of OIC by the American Gastroenterological Association (AGA) guidelines and the European Society for Medical Oncology (ESMO) guidelines [3,4] .
The incidence of pain in patients with advanced cancer can reach 60%-80%, of which about one-third of patients have experienced moderate to severe pain. Opioids are one of the main methods for treating chronic pain in cancer patients, but 60%-90% of patients will experience OIC symptoms [5] , which seriously affects the quality of life and treatment compliance of patients. How to effectively treat OIC and balance analgesia and adverse reactions has become one of the urgent problems to be solved in clinical practice.
Currently, laxatives commonly used in clinical practice to treat OIC may cause gastrointestinal adverse reactions such as nausea, vomiting, diarrhea, and abdominal pain, and they only treat the symptoms, not the root cause. Although opioid receptor antagonists can reduce the gastrointestinal effects of opioids and relieve constipation, they may reduce the analgesic effect of opioids by crossing the blood-brain barrier [6] . Nadimedin selectively acts on intestinal μ-opioid receptors, has no risk of electrolyte disturbance, is suitable for the long-term medication needs of OIC patients, and hardly enters the central nervous system. No effect on the analgesic effect of opioids has been found.
Chia Tai Tianqing Pharmaceutical Group will join hands with Shionogi to further deepen strategic cooperation, steadily promote the launch and promotion of naldemeton-methyl in mainland China, and strive to bring this innovative drug to more OIC patients in China as soon as possible, thus helping to improve the level of supportive care for cancer in my country.
Regarding Nadimeiding

Naldimemidin is an opioid receptor antagonist with binding affinity for μ, δ and κ opioid receptors. In tissues such as the gastrointestinal tract, naledimemidin acts as a peripheral μ opioid receptor antagonist, thereby reducing the constipation-inducing effect of opioids [1] . Naldimemidin is a derivative of naltrexone, which increases molecular weight and polar surface area by introducing a side chain, thereby reducing its ability to cross the blood-brain barrier (BBB). Naldimemidin is also a substrate of the P-glycoprotein (P-gp) efflux transporter. Based on these properties, it is expected that the permeability of naledimemidin to the central nervous system (CNS) at recommended dose levels is negligible, thus reducing the possibility of it interfering with the central analgesic effect of opioids [1] .
Multiple non-clinical and clinical studies have also shown that, after oral administration, naldemeton-methyl can effectively treat OIC by antagonizing the effects of opioids on peripheral intestinal receptors, without reducing the analgesic effect mediated by opioids acting on CNS receptors.

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