Methadone in Pain Management: A Systematic Review

Adequate analgesia can be challenging, as pharmacological options are not necessarily effective for all types of pain and are associated with adverse effects. Methadone is increasingly being considered in the management of both cancer-related and noncancer-related pain. The purpose of this article is to provide a narrative review of all available randomized controlled trials (RCTs) investigating the effectiveness of methadone in the management of pain, in relation to a comparison drug. The primary outcome was analgesic effectiveness, and the secondary outcomes were side effects and cost. A search of PubMed, Medline, Embase, and Google Scholar databases was conducted to identify eligible RCTs and methodologic quality was assessed. A total of 40 RCTs were included in this review. The majority compared methadone to morphine or fentanyl. Analgesic effectiveness of methadone was demonstrated in different types of pain, including postprocedural, cancer-related, nociceptive, and neuropathic pain. The evidence demonstrates that the use of methadone in postprocedural pain and in cancer-related pain may be dependent on the procedure and cancer type, respectively. Side effects experienced were generally similar to the comparison drug, and lower cost was a benefit to using methadone. Methadone may also be useful as an adjunctive analgesic for adequate pain control, as well as in patients with renal impairment. Additional high-quality, large-scale RCT evidence is needed to establish its role as monotherapy or as an adjunctive medication. Future research should also aim to standardize reported outcomes for measuring analgesic effectiveness to permit for pooled analysis across studies.PerspectiveThis article presents a systematic review, which includes a summary of published RCTs investigating the effectiveness of methadone in the management of pain. This is important for determining its analgesic utility and for identifying gaps in existing knowledge.     

Genetic Contexts of blaNDM-1 in Patients Carrying Multiple NDM-Producing Strains

The carbapenem resistance determinant bla_NDM-1 has been found in various Gram-negative bacteria and upon different plasmid replicon types (Inc). Here, we present four patients within two hospitals in Pakistan harboring between two and four NDM-1-producing Gram-negative bacilli of different species coresident in their stool samples. We characterize the bla_NDM-1 genetic contexts of these 11 NDM-1-producing Gram-negative bacilli in addition to other antimicrobial resistance mechanisms, plasmid replicon profiles, and sequence types (STs) in order to understand the underlying acquisition mechanisms of carbapenem resistance within these bacteria. Two common plasmid types (IncN2 and IncA/C) were identified to carry bla_NDM-1 among the six different bacterial species isolated from the four patients. Two of these strains were novel Citrobacter freundii ST 20 and ST 21. The same IncN2-type bla_NDM-1 genetic context was found in all four patients and within four different species. The IncA/C-type bla_NDM-1 genetic context was found in two different species and in two of the four patients. Combining genetic context characterization with other molecular epidemiology methods, we were able to establish the molecular epidemiological links between genetically unrelated bacterial species by linking their acquisition of an IncN2 or IncA/C plasmid carrying bla_NDM-1 for carbapenem resistance. By combining plasmid characterization and in-depth genetic context assessment, this analysis highlights the importance of plasmids in antimicrobial resistance. It also provides a novel approach for investigating the underlying mechanisms of bla_NDM-1-related spread between bacterial species and genera via plasmids.     

Hypertension in patients with pheochromocytoma

Adrenal-dependent hypertension syndromes are uncommon forms of hypertension. They include primary aldosteronism, pheochromocytoma, Cushing"s syndrome, and congenital adrenal hyperplasia. Pheochromocytomas are the cause of hypertension in 0.1% to 0.2% of hypertensive patients. Excess catecholamine release and other neural and humoral mechanisms contribute to the pathophysiology of hypertension. Patients with pheochromocytomas have a potentially curable cause of endocrine hypertension and, if undetected, pheochromocytomas confer a high risk for morbidity and mortality, especially during surgical procedures and pregnancy. All patients with incidental adrenal tumors, regardless of tumor size, should be biochemically screened for pheochromocytoma (especially before resection or needle biopsy) to avoid precipitation of a lethal hypertensive crisis.