Used primarily to treat opioid-induced constipation, especially in patients with chronic pain or those receiving palliative care. It works by blocking the effects of opioids in the gastrointestinal tract without affecting pain relief in the central nervous system. This selective action helps restore normal bowel function. Commonly administered as an injectable or oral formulation in clinical settings where long-term opioid use leads to severe constipation unresponsive to conventional laxatives.