The Management of Opioid-Induced Constipation in Cancer and Advanced Illness: A Meta-Analysis

CONTEXT

Constipation is a common problem among patients with cancer. By some accounts, about 60% of cancer patients experience constipation. There is limited empirical evidence of the clinical effectiveness of pharmacologic agents in opioid-induced constipation in advanced diseases.

OBJECTIVES

We sought to quantitatively summarize the therapeutic effectiveness of the pharmacologic means of managing opioid-induced constipation.

METHODS

Randomized control trials (RCTs) identified from medical literature databases that reported quantitative measures of the effect of pharmacotherapeutic agents to treat opioid induced constipation in patients with cancers and other advanced illnesses were included in this study. A conventional random effects meta-analysis was conducted including >3 trials with the same exposure and outcome assessed, and a network-meta-analysis was conducted for all placebo-controlled trials.

RESULTS

Eighteen studies that examined the effect of various pharmacotherapeutic agents were included. The medications were Methylnatrexone (N = 5), Naldemedine (N = 5), other conventional agents (N = 4) and herbal medicines (N = 4). In conventional meta-analysis, methylnaltrexone increased the proportion achieving rescue-free laxation by 2.68 fold (95% CI: 1.34, 5.37; P = 0.0054) within 4 hours of the administration compared to placebo. In network meta-analysis, the pooled RR of the pharmacotherapeutic agents on rescue-free bowel movements as 2.26 (95% CI: 1.52, 3.36) for methylnaltrexone, 1.58 (95% CI: 0.94, 2.66) for naldemedine, and 0.74 (95% CI: 0.45, 1.23) for polyethylene glycol, compared to placebo.

CONCLUSION

Methylnatrexone and Naldemedine have currently shown promise in randomized trials concerning opioid-induced constipation in cancer and advanced illness. It is imperative that future research ascertain not just the relative therapeutic efficacy but also the cost-benefit analyses of these newer regimens with more commonly used and accessible laxatives.

STAGED VERSUS SIMULTANEOUS APPROACH IN COMPLEX BILATERAL TOTAL KNEE REPLACEMENT: EXPERIENCE FROM TERTIARY INSTITUTION IN NIGERIA

Background

Bilateral end-stage knee osteoarthritis is a common presentation. The decision facing both patient and surgeon is whether to undertake the replacement of both knees in one sitting i.e. simultaneous bilateral total knee replacement (SMTKR) or to undertake this as a staged bilateral total knee replacement (STTKR). The decision is made harder by the presence of severe coronal and sagittal plane deformities and associated bone loss. We present our results of treating such patients with a focus on a trilogy of cost, complication and functional outcome following SMTKR.

Methodology

A retrospective review of 31 patients who presented with bilateral knee arthritis. 19 underwent SMTKR and 12 underwent STTKR. Data on the trilogy of complication, cost and functional outcome were collected and analysed.

Results

Our cohort of patients was overwhelmingly female in both groups at overall F/M = 30/1. Patients in the SMTKR group were slightly younger at a mean of 65 years compared to 69 years in the STTKR group. Mean Oxford Knee Score (OKS) improved significantly in all groups, mean of 54 in SMTKR and 56 in the STTKR groups. There was one fatality in the STTKR from upper GI bleeding and 1 revision for bone graft failure. The overall cost is less with SMTKR.

Summary

SMTKR is a safe and effective undertaking in properly selected patients with bilateral end-stage knee arthritis with severe deformities. Significant experience is however needed to successfully tackle complex deformities and such procedures should be undertaken by experienced arthroplasty surgeons.