Effect of Ultra-low-dose Naloxone on Ileus after Cesarean Section: A Randomized Clinical Trial

Postoperative ileus commonly occurs after abdominal surgeries, often leading to longer hospital stays. While intravenous opioids are effective for pain management, they can extend ileus duration. Ultra-low-dose naloxone presents a promising strategy to improve pain control and minimize side effects. This study examines how ultra-low-dose naloxone impacts ileus after cesarean section.

Seventy participants were randomly divided into two groups: 35 patients in the intervention group received a patient-controlled analgesia (PCA) pump with 30 mg of morphine, 0.25 μg/kg/h of naloxone, and saline, whereas 35 patients in the control group received morphine and saline only. Patients assessed their pain, nausea, and pruritus using a 0-10-point Visual Analog Scale upon arrival at the recovery room and then at 30 min, 60 min, 90 min, 120 min, 6 h, 12 h, and 24 h after surgery. We recorded the duration of ileus, time to tolerate liquids and solids, discharge timing, and analgesic consumption.

The control group (n = 35) experienced longer ileus duration (P < 0.001), greater pain severity (P = 0.02), and higher levels of nausea (P = 0.04) and pruritus (P = 0.02) compared to the intervention group (n = 34). Liquid tolerance time was also significantly longer in the control group (P = 0.006). There were no significant differences between the groups in solids tolerance time, opioid use, or hospital stay.

Ultra-low-dose naloxone can effectively reduce postoperative ileus, improve opioid analgesia, and decrease side effects such as pruritus and nausea.