methylnaltrexone + codeine

Methylnaltrexone + codeine is a combination of two drugs with opposing actions on opioid receptors. Methylnaltrexone is a peripherally acting μ-opioid receptor antagonist, primarily used to treat opioid-induced constipation by blocking the effects of opioids like codeine in the gastrointestinal tract without affecting their pain-relieving properties in the central nervous system[1][3][4][5][6]. Codeine is an opioid analgesic that acts as an agonist at μ-opioid receptors to provide pain relief. When used together, this combination could theoretically allow for effective pain management with reduced risk of opioid-induced constipation, though such combinations are not standard clinical practice and may be considered investigational or off-label.

Brand names

Relistor (for methylnaltrexone)

Other names

MNTX (for methylnaltrexone)naltrexone-methyl-bromide (for methylnaltrexone)