Postoperative ileus (POI) and constipation are common secondary effects of opioids and carry significant clinical and economic impacts. μ-Opioid receptors mediate opioid analgesia in the central nervous system (CNS) and gastrointestinal-related effects in the periphery. Peripherally acting μ-opioid receptor antagonists (PAMORAs) block the peripheral effects of opioids in the gastrointestinal tract, while maintaining opioid analgesia in the CNS. While most are not approved for POI or postoperative opioid-induced constipation (OIC), PAMORAs have a potential role in these settings via their selective effects on the μ-opioid receptor. This review will discuss recent clinical trials evaluating the safety and efficacy of PAMORAs, with a focus on alvimopan (Entereg^®) and methylnaltrexone (Relistor^®) in patients with POI or postoperative OIC. We will characterize potential factors that may have impacted the efficacy observed in phase 3 trials and discuss future directions for the management and treatment of POI.

BACKGROUND: Upper tract urothelial carcinoma (UTUC) is a heterogeneous disease that presents a clinical management challenge for the urologic surgeon. We assessed treatment patterns, costs, and survival outcomes among patients with nonmetastatic UTUC. METHODS: We identified 4114 patients diagnosed with nonmetastatic UTUC from 2004 to 2013 in the Survival Epidemiology, and End Results-Medicare population-based database. Patients were stratified into low- or high-risk disease groups. Median total costs from 30 days prior to diagnosis through 365 days after diagnosis were compared between groups. Overall and cancer-specific survival were evaluated using Cox proportional hazards regression. All statistical tests were 2-sided. RESULTS: After risk stratification, 1027 (24.9%) and 3087 (75.0%) patients were classified into low- vs high-risk UTUC groups. Most patients underwent at least 1 surgical intervention (95.1%); 68.4% underwent at least 1 endoscopic intervention. Patients diagnosed with high- vs low-risk UTUC were more likely to undergo nephroureterectomy (83.6% vs 72.0%; P < .001); few patients with low-risk disease were exclusively managed endoscopically (16.9%). At 365 days after diagnosis, costs of care for high- vs low-risk UTUC were statistically significantly higher ($108 520 vs $91 233; median difference $16 704, 95% confidence interval [CI] = $11 619 to $21 778; P < .001). Those with high-risk UTUC had worse cancer-specific and overall survival compared with patients with low-risk UTUC (cancer-specific survival hazard ratio [HR] = 4.14, 95% CI = 3.19 to 5.37; overall survival HR = 1.78, 95% CI = 1.62 to 1.96). CONCLUSIONS: UTUC continues to be managed primarily with nephroureterectomy, regardless of risk stratification, and patients with high-risk UTUC have worse overall and cancer-specific survival. Substantial costs are associated with management of low- and high-risk UTUC, with the latter being more costly up to 1 year from diagnosis.