Torsade de pointes caused by polypharmacy and substance abuse in a patient with human immunodeficiency virus

Drug-induced QT prolongation is a potentially dangerous adverse effect of some medication combinations. When QT prolongation progresses to torsade de pointes, life-threatening or fatal outcomes may result. A 57-year-old man with a history of human immunodeficiency syndrome on abacavir, nevirapine, tenofovir, voriconazole, and methadone presented to the emergency department with a chief complaint of new-onset seizures. The physical exam was unremarkable. The electrocardiogram demonstrated sinus bradycardia and a prolonged QTc interval of 690 ms. In the emergency department, he had several episodes of torsade de pointes (TdP) and ventricular tachycardia that resolved spontaneously. These episodes were accompanied by an alteration in mentation and generalized twitching. Magnesium and amiodarone were effective in terminating the dysrhythmia. The patient had multiple risk factors for prolonged QT syndrome including human immunodeficiency virus infection, methadone therapy, and polypharmacy leading to potential drug interactions. Physicians must be aware of multidrug interactions potentiating QT prolongation and leading to torsade de pointes

Dose patterns in commercially insured subjects chronically exposed to opioids: a large cohort study in the United States

<p>Abstract</p> <p>Background</p> <p>Little data exist on how opioid doses vary with the length of exposure among chronic opioid users.</p> <p>Methods</p> <p>To characterize the change in the dosage of opioids over time, a retrospective cohort study using the PharMetrics database for the years 1999 through 2008 was conducted. Individuals exposed to opioids in 2000 who had 2 opioid dispensings at least 6 months apart and were opioid naive (did not receive any opioid 6 month before their exposure in 2000) were included. The date of the first dispensing in 2000 was defined as the index date and the dispensing had to be for a strong and full agonist opioid. All opioid doses were converted to oral morphine equivalent doses. Exposure was classified as continuous or intermittent. Mean, median, interquartile range, and 95^thpercentile of opioid dose over 6-month periods, as well as the percentage of subjects who ever received a high or very high opioid dose, were calculated.</p> <p>Results</p> <p>Among the 48,986 subjects, the mean age was 44.5 years and 54.5% were women. Intermittent exposure was observed in 99% of subjects; continuous exposure was observed in 1% of subjects. The mean duration of exposure for the subjects who were continuously exposed to opioids was 477 days. In subjects with no cancer diagnosis who were continuously exposed to opioids, the mean, 25^th, 50^th, and 75^thpercentile of dose was stable during the first 2 years of use, but the 95^thpercentile increased. Seven percent of them were exposed to doses of 180 mg or more of morphine at some point.</p> <p>Conclusions</p> <p>Dose escalation is uncommon in subjects with intermittent exposure to opioids. For subjects with continuous exposure to opioids who have cancer, doses rise substantially with time. For those without cancer, doses remain relatively stable for the first 2 years of use, but subsequently increase. Seven percent of subjects with no cancer diagnosis will be exposed to daily doses of 180 mg or more of morphine equivalent at some point.</p

Adsorption of hydroxamate siderophores and EDTA on goethite in the presence of the surfactant sodium dodecyl sulfate

Siderophore-promoted iron acquisition by microorganisms usually occurs in the presence of other organic molecules, including biosurfactants. We have investigated the influence of the anionic surfactant sodium dodecyl sulfate (SDS) on the adsorption of the siderophores DFOB (cationic) and DFOD (neutral) and the ligand EDTA (anionic) onto goethite (α-FeOOH) at pH 6. We also studied the adsorption of the corresponding 1:1 Fe(III)-ligand complexes, which are products of the dissolution process. Adsorption of the two free siderophores increased in a similar fashion with increasing SDS concentration, despite their difference in molecule charge. In contrast, SDS had little effect on the adsorption of EDTA. Adsorption of the Fe-DFOB and Fe-DFOD complexes also increased with increasing SDS concentrations, while adsorption of Fe-EDTA decreased. Our results suggest that hydrophobic interactions between adsorbed surfactants and siderophores are more important than electrostatic interactions. However, for strongly hydrophilic molecules, such as EDTA and its iron complex, the influence of SDS on their adsorption seems to depend on their tendency to form inner-sphere or outer-sphere surface complexes. Our results demonstrate that surfactants have a strong influence on the adsorption of siderophores to Fe oxides, which has important implications for siderophore-promoted dissolution of iron oxides and biological iron acquisition

Probing of Exosites Leads to Novel Inhibitor Scaffolds of HCV NS3/4A Proteinase

Hepatitis C is a treatment-resistant disease affecting millions of people worldwide. The hepatitis C virus (HCV) genome is a single-stranded RNA molecule. After infection of the host cell, viral RNA is translated into a polyprotein that is cleaved by host and viral proteinases into functional, structural and non-structural, viral proteins. Cleavage of the polyprotein involves the viral NS3/4A proteinase, a proven drug target. HCV mutates as it replicates and, as a result, multiple emerging quasispecies become rapidly resistant to anti-virals, including NS3/4A inhibitors.To circumvent drug resistance and complement the existing anti-virals, NS3/4A inhibitors, which are additional and distinct from the FDA-approved telaprevir and boceprevir α-ketoamide inhibitors, are required. To test potential new avenues for inhibitor development, we have probed several distinct exosites of NS3/4A which are either outside of or partially overlapping with the active site groove of the proteinase. For this purpose, we employed virtual ligand screening using the 275,000 compound library of the Developmental Therapeutics Program (NCI/NIH) and the X-ray crystal structure of NS3/4A as a ligand source and a target, respectively. As a result, we identified several novel, previously uncharacterized, nanomolar range inhibitory scaffolds, which suppressed of the NS3/4A activity in vitro and replication of a sub-genomic HCV RNA replicon with a luciferase reporter in human hepatocarcinoma cells. The binding sites of these novel inhibitors do not significantly overlap with those of α-ketoamides. As a result, the most common resistant mutations, including V36M, R155K, A156T, D168A and V170A, did not considerably diminish the inhibitory potency of certain novel inhibitor scaffolds we identified.Overall, the further optimization of both the in silico strategy and software platform we developed and lead compounds we identified may lead to advances in novel anti-virals

Accommodating Dynamic Oceanographic Processes and Pelagic Biodiversity in Marine Conservation Planning

Pelagic ecosystems support a significant and vital component of the ocean's productivity and biodiversity. They are also heavily exploited and, as a result, are the focus of numerous spatial planning initiatives. Over the past decade, there has been increasing enthusiasm for protected areas as a tool for pelagic conservation, however, few have been implemented. Here we demonstrate an approach to plan protected areas that address the physical and biological dynamics typical of the pelagic realm. Specifically, we provide an example of an approach to planning protected areas that integrates pelagic and benthic conservation in the southern Benguela and Agulhas Bank ecosystems off South Africa. Our aim was to represent species of importance to fisheries and species of conservation concern within protected areas. In addition to representation, we ensured that protected areas were designed to consider pelagic dynamics, characterized from time-series data on key oceanographic processes, together with data on the abundance of small pelagic fishes. We found that, to have the highest likelihood of reaching conservation targets, protected area selection should be based on time-specific data rather than data averaged across time. More generally, we argue that innovative methods are needed to conserve ephemeral and dynamic pelagic biodiversity

Effect of electroacupuncture on opioid consumption in patients with chronic musculoskeletal pain: protocol of a randomised controlled trial

This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The electronic version of this article is the complete one and can be found online at: http://www.trialsjournal.com/content/13/1/169BACKGROUND Chronic musculoskeletal pain is common and has been increasingly managed by opioid medications, of which the long-term efficacy is unknown. Furthermore, there is evidence that long-term use of opioids is associated with reduced pain control, declining physical function and quality of life, and could hinder the goals of integrated pain management. Electroacupuncture (EA) has been shown to be effective in reducing postoperative opioid consumption. Limited evidence suggests that acupuncture could assist patients with chronic pain to reduce their requirements for opioids. The proposed research aims to assess if EA is an effective adjunct therapy to standard pain and medication management in reducing opioids use by patients with chronic musculoskeletal pain. METHODS In this multicentre, randomised, sham-acupuncture controlled, three-arm clinical trial, 316 patients regularly taking opioids for pain control and meeting the defined selection criteria will be recruited from pain management centres and clinics of primary care providers in Victoria, Australia. After a four-week run-in period, the participants are randomly assigned to one of three treatment groups to receive EA, sham EA or no-EA with a ratio of 2:1:1. All participants receive routine pain medication management delivered and supervised by the trial medical doctors. Twelve sessions of semi-structured EA or sham EA treatment are delivered over 10 weeks. Upon completion of the acupuncture treatment period, there is a 12-week follow-up. In total, participants are involved in the trial for 26 weeks. Outcome measures of opioid and non-opioid medication consumption, pain scores and opioid-related adverse events are documented throughout the study. Quality of life, depression, function, and attitude to pain medications are also assessed. DISCUSSION This randomised controlled trial will determine whether EA is of significant clinical value in assisting the management of debilitating chronic pain by reducing opioids consumption and their associated adverse events, as well as improving the quality of life for those with chronic pain. Such an outcome will provide the rationale for including EA into multidisciplinary programmes for effective management of chronic musculoskeletal pain. TRIAL REGISTRATION Australian New Zealand Clinical Trial Registry (ACTRN12609000676213) http://www.anzctr.org.au/trial_view.aspx?ID=308008Charlie CL Xue, Robert D Helme, Stephen Gibson, Malcolm Hogg, Carolyn Arnold, Andrew A Somogyi, Cliff Da Costa, Yanyi Wang, Shao-chen Lu and Zhen Zhen