Alvimopan* (ADL 8-2698) is a novel peripheral opioid antagonist

Area of Science:

• Gastroenterology
• Pharmacology
• Clinical Medicine

Background:

• Opioid antagonists are crucial for managing gastrointestinal side effects of opioid therapy.
• Alvimopan is a novel, peripherally restricted opioid antagonist with high affinity for mu-opioid receptors.
• Its activity is specific to the gastrointestinal tract with low systemic absorption.

Purpose of the Study:

• To evaluate the efficacy and safety of Alvimopan in managing postoperative ileus (POI).
• To assess Alvimopan's effect on opioid-induced bowel dysfunction (OBD) in patients with chronic pain or opioid addiction.
• To determine if Alvimopan compromises opioid analgesia or induces central nervous system withdrawal symptoms.

Main Methods:

• Clinical trials involving opioid-naive surgical patients receiving opioids for acute pain.
• Studies in patients with chronic pain or opioid addiction treated with opioids.
• Administration of oral Alvimopan at varying doses (6.0 mg for POI, 0.5-3.0 mg for OBD).
• Assessment of gastrointestinal transit, pain scores, opioid consumption, and side effects.

Main Results:

• Alvimopan (6.0 mg) shortened time to normal bowel function and hospital stay in POI patients.
• It reduced postoperative nausea, vomiting, and GI side effects without affecting analgesia.
• Lower doses (0.5-3.0 mg) reversed OBD and normalized GI activity in chronic pain patients without compromising analgesia or causing central withdrawal.
• Localized GI side effects were reported at higher doses in some chronic pain patients.

Conclusions:

• Alvimopan is effective in managing POI and OBD.
• It offers a favorable safety profile, improving GI function without compromising central opioid effects.
• Further clinical studies are ongoing to confirm its efficacy and safety in practice.