Methylnaltrexone-Associated Bowel Perforation in Postoperative Opioid-Induced Constipation and Ogilvie Syndrome: A Case Report

Naldemedine-induced perforation of a diverticulum in the sigmoid colon of a patient with opioid-related constipation: a case report

BACKGROUND

Naldemedine is an orally available peripherally acting μ-opioid receptor antagonist approved to treat opioid-induced constipation (OIC). It is contraindicated for patients with known or suspected gastrointestinal obstruction to protect against naldemedine-induced perforation. Here, we report a clinical case of suspected perforation of a diverticulum in the sigmoid colon associated with naldemedine.

CASE PRESENTATION

The patient was a 65-year-old man with a history of oral cancer who had been prescribed oxycodone (20 mg/day) for cancer pain. On day 0, the patient started naldemedine 0.2 mg once daily before bedtime for OIC. The dose of oxycodone was increased for pain control up to 60 mg/day. On day 35 of naldemedine treatment, the patient developed fever and abdominal pain, and his frequency of defecation had decreased. Initial laboratory results showed a C-reactive protein (CRP) level of 28.5 mg/dL and white blood cell (WBC) count of 13,500/µL. On day 37, the patient still had tenderness in his lower abdomen. Abdominal computed tomography revealed free air in the abdominal cavity suggesting an intestinal perforation. A Hartmann procedure was performed. Histopathological findings showed numerous diverticula in the sigmoid colon, some of which were perforated.

CONCLUSIONS

These results suggest that the effects of OIC may have compressed the intestinal tract, which was followed by naldemedine-activation of peristalsis, which led to the onset of intestinal perforation. In patients with pre-existing diverticular disease, we should monitor for increased WBC counts and CRP levels after the initiation of treatment with naldemedine, and consider performing appropriate tests early in the event of abdominal complaints.

The Efficacy and Safety of Methylnaltrexone for the Treatment of Postoperative Ileus

BACKGROUND

Postoperative ileus (POI) is a surgical complication resulting in increased morbidity and length of stay (LOS). Usual care for POI includes bowel rest and gastric decompression. It has been questioned if methylnaltrexone (MNTX), a peripheral opioid antagonist, could be used as treatment for POI. The purpose of this study was to determine if MNTX is effective and safe for POI treatment.

METHODS

This single-center, retrospective cohort study included patients ⩾ 18 years with a POI. Patients with acute colonic pseudo-obstruction, small bowel obstruction, and gastrointestinal malignancy were excluded. The intervention was MNTX administration. The primary outcome was time to ileus resolution. Secondary outcomes included LOS, duration of nasogastric tube, total parenteral nutrition requirement, and incidence of gastrointestinal perforations.

RESULTS

110 patients were included in the analysis; 28 received MNTX. Time to ileus resolution was 9.9 days for the MNTX group and 11.4 days for the control group (P = .38). Duration of gastric decompression was 4.6 days for the MNTX group and 4.2 days for the control group (P = .71). Length of stay was 19.9 days for the MNTX group and 19.7 days for the control group (P = .96). The percentage of TPN requirement was 17.9% in the MNTX group and 22.0% in the control group (P = .65). No gastrointestinal perforations were observed in either group.

CONCLUSION

For the treatment of POI, MNTX did not significantly reduce time to resolution of ileus, LOS, duration of gastric decompression, or TPN requirements. However, no gastrointestinal perforations were seen, indicating that MNTX may be safely used in these patients.

Efficacy and Safety of Peripherally Acting μ-Opioid Receptor Antagonist (PAMORAs) for the Management of Patients With Opioid-Induced Constipation: A Systematic Review

In treating chronic and acute pain, opioids are widely used. Although they do provide analgesia, their usage does come with adverse events (AEs). One of the most burdensome is opioid-induced bowel dysfunction, and more specifically opioid-induced constipation (OIC). The pathogenesis of these AEs is well known as the consequence of the action of opioids on m-receptors in the enteric nervous system. In recent years, medicines counteracting this specific action at the receptors have been registered for clinical use: the peripherally acting μ-opioid receptor antagonists (PAMORAs). The knowledge of their comparative efficacy and tolerability is very important for physicians and patients in opioid therapy. This systematic review of the existing literature on PAMORAs aimed to study the relative clinical advantages and disadvantages. The most important data banks, including "PubMed," "Embase," "CT.gov," "ICTRP" and "CINAHL" were used to find the published material on PAMORAs. The selected publications were examined to systematically analyze the efficacy and safety of the four existing PAMORAs. All of the medications are superior to placebo in reducing OIC. There are few published data on alvimopan used to treat OIC, and it is only indicated for the treatment of post-abdominal surgery ileus. Methylnaltrexone is studied mainly in its subcutaneous (SC) formulation. When used in its oral formulation, it seems more rapid than naloxegol and placebo in the reduction of OIC. Naldemedine is able to produce more spontaneous bowel movements (SBMs) when compared to alvimopan and naloxegol. Tolerability was found to be similar for all of them. In particular, they affect the gastrointestinal tract (GI), with flatulence and diarrhea, especially at high dosages. For some of them, nasopharyngitis and abdominal pain were observed as treatment adverse effects (TEAs). Several cardiovascular TEAs were reported after methylnaltrexone use, but it is not clear whether they were consequences of the drug or related to the general conditions of the patients. Considering the existing data, naloxegol and naldemedine seem to be the best choices, with a higher number of spontaneous bowel movements following naldemedine administration.

Efficacy and Safety of Methylnaltrexone for the Treatment of Opioid-Induced Constipation: A Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Opioid-induced constipation (OIC) is a distressing side effect during opioid analgesia and is mainly mediated by gastrointestinal μ-opioid receptors. Methylnaltrexone, a peripheral μ-opioid receptor antagonist with restricted ability to cross the blood-brain barrier, may alleviate OIC without reversing analgesia. We performed a meta-analysis to assess the efficacy and safety of methylnaltrexone for the treatment of OIC.

METHODS

This meta-analysis was registered in PROSPERO (CRD42020187290). We searched PubMed, Embase, and Cochrane Library for randomized controlled trials that compared methylnaltrexone with placebo for the treatment of OIC. Relative risks (RR) and 95% confidence interval (CI) were pooled using a random-effects model. We used the GRADE approach to assess the certainty of the evidence.

RESULTS

Eight trials with 2034 participants were included. Compared with placebo, methylnaltrexone significantly increased rescue-free bowel movement (RFBM) within 4 h after the first dose (eight trials; 1833 participants; RR 3.74, 95% CI 3.02-4.62; high-certainty evidence), RFBM within 24 h after the first dose (two trials; 614 participants; RR 1.98, 95% CI 1.52-2.58; moderate-certainty evidence), and RFBM ≥ 3 times per week (three trials; 1,396 participants; RR 1.33, 95% CI 1.17-1.52; moderate-certainty evidence) and decreased need to take rescue laxatives (three trials; 807 participants; RR 0.73, 95% CI 0.63-0.85; moderate-certainty evidence). For safety outcomes, there was no difference in any adverse events between the two groups (eight trials; 2034 participants; RR 1.11, 95% CI 0.99-1.23; moderate-certainty evidence), including diarrhea, nausea, vomiting, and flatulence; but for the most commonly reported adverse events, the abdominal pain was higher in methylnaltrexone group than that in placebo group (six trials; 1813 participants; RR 2.30, 95% CI 1.29-4.08; moderate-certainty evidence).

CONCLUSION

Methylnaltrexone is an effective and safe drug for the treatment of OIC, but the safety of abdominal pain should be considered.

The efficacy of docusate sodium and senna glycoside for the treatment of constipation after rotator cuff repair: A randomized controlled study

BACKGROUND

Although stool softeners and laxatives are commonly prescribed for postoperative constipation, it is unclear if they are effective during the postoperative period. The data gained from this study will be beneficial for advanced practitioners when examining for postoperative constipation concerns.

PURPOSE

This study aimed to investigate the efficacy of docusate sodium and senna glycoside in the prevention and treatment of constipation following rotator cuff repair (RCR).

METHODS

Patients (n = 107) were randomized to receive docusate sodium, senna glycoside, or nothing (control) in addition to a standardized postoperative protocol. Patients maintained a daily bowel-movement log for postoperative days 0-10. Constipation symptoms and quality of life were assessed preoperatively and at 2 and 6 weeks postoperatively using the Patient Assessment of Constipation Symptoms (PAC-SYM) and Patient Assessment of Constipation Quality of Life (PAC-QOL) questionnaires.

RESULTS

Sixty-seven percent of patients experienced constipation. There was no difference in the prevalence of constipation in the docusate, senna, and control groups (71.4%, 66.7%, and 64.3%, respectively; p = .88). Neither PAC-SYM nor PAC-QOL scores significantly differed between the 3 groups at any time point during 6-week follow-up (p > .05).

IMPLICATIONS FOR PRACTICE

The majority (67%) of patients experience postoperative constipation following RCR. Although docustate sodium and senna glycoside are common first-line agents for the treatment of constipation, they are ineffective during the postoperative period. Providers need to explore other treatment modalities for postoperative constipation pain.