From: The effect of opioids on gastrointestinal function in the ICU
Opioids antagonists | Mechanism of action | Administration | Recommended dose | Approved indication | Side effects | Contraindications |
---|---|---|---|---|---|---|
Methylnaltrexone | PAMORA | Subcutaneous injection Oral | 8 mg (BW 38–62 kg) 12 mg (BW 63–114 kg) 0.15 mg/kg for patients with weights outside of these ranges | OIC patients, lower GI paralysis, insufficient response to laxatives | GI Perforation abdominal pain, nausea, diarrhea, flatulence | Known or suspected mechanical GI obstruction, perforation |
Alvimopan | PAMORA | Oral | 12 mg BID (limited to 15 doses) | Postoperative ileus, partial bowel resection, primary anastomosis | MI, anemia, dyspepsia, hypokalemia, back pain, urinary retention | Opiate use > 1 week |
Naloxegol | Antagonist of DOR, KOR and MOR | Oral | 12.5–25 mg OD | OIC in non-cancer and chronic pain patients, inadequate response to laxative therapy | Nausea, vomiting, diarrhea, abdominal pain, and bowel obstruction, flatulence, MI and QT prolongation less than Alvimopan | Patients with known or suspected GI obstruction are at increased risk of perforation |
Naloxone | Opioid receptor antagonist mediated both peripheral and central | Oral | 3–12 mg TID | Constipation, lower GI paralysis | Symptoms of opioid withdrawal, reversal of analgesic | Hypersensitivity to the drug |
Naldemedine | Peripherally acting DOR, KOR and MOR antagonist | Oral | 0.2Â mg OD | OIC patients | Abdominal pain, diarrhea, nausea, gastroenteritis | Suspected or known GI perforation, obstruction and severe hepatic disease |