Used primarily to treat opioid-induced constipation, especially in patients with advanced illness or chronic pain who do not respond well to conventional laxatives. It works peripherally to block opioid receptors in the gut without affecting pain relief in the central nervous system. Commonly administered via subcutaneous injection or oral formulation, it helps restore bowel function quickly, often within hours. Its selective action makes it suitable for long-term management in palliative care and chronic pain settings.