Background: Opioid use, abuse, and adverse consequences, including death, have escalated at an alarming rate since the 1990s. In an attempt to control opioid abuse, numerous regulations and guidelines for responsible opioid prescribing have been developed by various organizations. However, the US opioid epidemic is continuing and drug dose deaths tripled during 1999 to 2015. Recent data show a continuing increase in deaths due to natural and semisynthetic opioids, a decline in methadone deaths, and an explosive increase in the rates of deaths involving other opioids, specifically heroin and illicit synthetic fentanyl. Contrary to scientific evidence of efficacy and negative recommendations, a significant proportion of physicians and patients (92%) believe that opioids reduce pain and a smaller proportion (57%) report better quality of life. In preparation of the current guidelines, we have focused on the means to reduce the abuse and diversion of opioids without jeopardizing access for those patients suffering from non-cancer pain who have an appropriate medical indication for opioid use. Objectives: To provide guidance for the prescription of opioids for the management of chronic non-cancer pain, to develop a consistent philosophy among the many diverse groups with an interest in opioid use as to how appropriately prescribe opioids, to improve the treatment of chronic non-cancer pain and to reduce the likelihood of drug abuse and diversion. These guidelines are intended to provide a systematic and standardized approach to this complex and difficult arena of practice, while recognizing that every clinical situation is unique. Methods: The methodology utilized included the development of objectives and key questions. The methodology also utilized trustworthy standards, appropriate disclosures of conflicts of interest, as well as a panel of experts from various specialties and groups. The literature pertaining to opioid use, abuse, effectiveness, and adverse consequences was reviewed, with a best evidence synthesis of the available literature, and utilized grading for recommendation as described by the Agency for Healthcare Research and Quality (AHRQ).

The opioid epidemic has resulted from myriad causes and will not be solved by any simple solution. Consequent to a staggering increase in opioid-related deaths in the USA, various governmental inputs and stakeholder strategies have been proposed and implemented with varying success. This article summarizes the history of opioid use and explores the causes for the present day epidemic. Recent trends in opioid-related data demonstrate an almost fourfold increase in overdose deaths from 1999 to 2008. Tragically, opioids claimed over 64,000 lives just last year. Some solutions have undergone legislation, including the limitation of numbers of opioids postsurgery, as well as growing national prevalence of enhanced recovery after surgery protocols which focus on reduced postoperative opioid consumption and shortened hospital stays. Stricter prescribing practices and prescription monitoring programs have been instituted in the recent past. Improvement in abuse deterrent strategies which is a major focus of the Food and Drug Administration (FDA) for all opioid preparations will likely play an important role by increasing the safety of these medications. Future potential strategies such as additional legislative policies, public awareness, and physician education are also detailed in this review.

The second-order rate constant, kcat/km, for catalysis of the hydrolysis of 4-nitrophenyl phosphate by alkaline phosphatase decreases with increasing viscosity in the presence of sucrose or arabinose, with a slope of delta[kcat/Km)0/(kcat/Km)]/delta(eta/eta 0) = 1.4 at pH 8.0, 25 degrees C. This is consistent with rate-limiting diffusional encounter of the substrate with active enzyme and indicates that alkaline phosphatase is a "perfect enzyme". However, the reported second-order rate constants of kcat/Km = 6.6 x 10(6) to 4.6 x 10(7) M-1 s-1 are smaller than the diffusional limit; this shows that only approximately 0.1-1% of the diffusional encounters are productive. The first-order rate constant, kcat, for rate-limiting hydrolysis of the phosphoenzyme intermediate at pH = 6 with saturating substrate concentration is independent of viscosity in aqueous sucrose solutions. This shows that sucrose does not destabilize the transition state for phosphoenzyme hydrolysis. However, at pH 8.0 product dissociation is rate limiting and kcat decreases with increasing viscosity in the presence of sucrose, with slopes of delta(k0/kobsd)/delta(eta/eta 0) = 1.2 in 0.04 M Mops buffer, 1.0 in 0.1 M Tris, and 1.2 in 0.67 M Tris buffer. This is consistent with rate-limiting diffusional separation of inorganic phosphate and of Tris phosphate from the enzyme. In contrast, glycerol causes a large decrease in kcat/Km at pH 8.0 and also decreases kcat at pH 6. This shows that glycerol decreases the rate by a solvent effect on the catalytic activity of the enzyme, as well as by increasing the viscosity.

Object Patients with radiculopathy, with or without back pain, often do not respond to conservative care and may be considered for epidural steroid injection therapy or a disc decompression procedure. Plasma disc decompression (PDD) using the Coblation SpineWand device is a percutaneous, minimally invasive interventional procedure. The purpose of this study was to evaluate clinical outcomes with PDD as compared with standard care using fluoroscopy-guided transforaminal epidural steroid injection (TFESI) over the course of 2 years. Methods This was a multicenter randomized controlled clinical study. Ninety patients (18–66 years old) who had sciatica (visual analog scale score ≥50) associated with a single-level lumbar contained disc herniation were enrolled. In all cases, their condition was refractory to initial conservative care and 1 epidural steroid injection had failed. Participants were randomly assigned to receive either PDD (46 patients) or TFESI (44 patients, up to 2 injections). Results The patients in the PDD Group had significantly greater reduction in leg pain scores and significantly improved Oswestry Disability Index and 36-Item Short Form Health Survey ([SF-36], physical function, bodily pain, social function, and physical components summary) scores than those in the TFESI Group. During the 2-year follow-up, 25 (56%) of the patients in the PDD Group and 11 (28%) of those in the TFESI Group remained free from having a secondary procedure following the study procedure (log-rank p = 0.02). A significantly higher percentage of patients in the PDD Group showed minimum clinically important change in scores for leg and back pain and SF-36 scores that exceeded literature-based minimum clinically important changes. Procedure-related adverse events, including injection site pain, increased leg or back pain, weakness, and lightheadedness, were observed in 5 patients in the PDD Group (7 events) and 7 in the TFESI Group (14 events). Conclusions In study patients who had radicular pain associated with a contained lumbar disc herniation, those patients treated with PDD had significantly reduced pain and better quality of life scores than those treated using repeated TFESI. In addition, significantly more PDD patients than TFESI patients avoided having to undergo a secondary procedure during the 2-year study follow-up.