HYDROMORPHONE HYDROCHLORIDE

12.1 Mechanism of Action Hydromorphone is a full opioid agonist and is relatively selective for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of hydromorphone is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia with morphine. Clinically, dosage is titrated to provide adequate analgesia and may be limited by adverse reactions, including respiratory and CNS depression. The precise mechanism of the analgesic action is unknown. However, specific CNS opioid receptors for endogenous compounds with opioid-like activity have been identified throughout the brain and spinal cord and are thought to play a role in the analgesic effects of this drug.

Contraindications

• • including paralytic ileus [see Warnings and Precautions (5.12) ] Hypersensitivity to hydromorphone
• • hydromorphone salts
• • any other components of the product
• • or sulfite-containing medications (e.g.
• • anaphylaxis) [see Warnings and Precautions (5.16)