Objective: To determine whether anecdotal reports of suspected adverse drug reactions are valuable early warning signals. Design: Systematic literature survey. Data sources: We evaluated all case reports of adverse drug reactions published in 1997 in five medical journals. Reports were excluded if the adverse reaction had previously been described in earlier publications and was already listed in the product information of the drug reference source (the British National Formulary (BNF) or the Medicines Compendium). We used the Web of Knowledge Citation Index and Medline for 2003 to identify follow-up studies. Main outcome measures: Primary: the number of suspected adverse reactions subjected to formal validation studies and the findings of these studies. Secondary: the number of instances in which the warning from the case report was incorporated into the product information. Results: We evaluated 63 suspected adverse reactions and found that most (52/63, 83%) had not yet been subjected to further detailed evaluation. Data from controlled studies that supported the postulated link between the drug and the adverse event were available in only three cases. Of the 48 agents listed in the drug reference sources, details of the suspected reaction were subsequently added to the Medicines Compendium in 15 instances, and to the BNF in seven instances. In each case, only one reaction had been confirmed. Conclusions: Published case reports of suspected adverse reactions are of limited value as suspicions are seldom subjected to confirmatory investigation. Furthermore, these alerts are not incorporated into drug reference sources in a systematic manner.
\n \n\n \n \nWe have studied the in vivo response of the Na+/H+ antiporter in skeletal muscle to beta 2-adrenoceptor stimulation with isoprenaline and the effect of blocking L-type calcium channels with nifedipine. Na+/H+ antiporter activity in skeletal muscle in vivo increased after beta 2-adrenoceptor stimulation with isoprenaline; nifedipine attenuated that effect. This suggests that opening of L-type calcium channels is necessary for full activation of the Na+/H+ antiporter in skeletal muscle. Bleeding also increased Na/H+ antiporter activity, which we believe could be explained by an increase in sympathetic nervous system activity as a result of hypotension. This may be one of the mechanisms by which animals under stress prepare their skeletal muscle for exercise as part of the 'fright and flight' reaction.
\n \n\n \n \n\u00a9 2016 The Author(s). Inhibition of the H+/K+-adenosine triphosphatase (the proton pump) is the final common mechanistic pathway in reducing gastric acid secretion pharmacologically. Proton pump inhibitors are widely used in upper gastrointestinal diseases, including gastric and duodenal ulcers, eradication of Helicobacter pylori in combination with antibiotics, gastroesophageal reflux disease, Zollinger-Ellison syndrome, eosinophilic esophagitis, and prevention of non-steroidal anti-inflammatory drug-induced peptic ulceration. Reviewing their benefits and harms in BMC Medicine, Scarpignato et al. report effectiveness in these conditions, and harms that are generally mild and uncommon (1-3 %). Serious adverse reactions, such as tubulointerstitial nephritis, are rare. However, the risks of gastric and pancreatic cancer are unclear. Drug-drug interactions can occur through effects on P glycoprotein and cytochrome P450 (CYP) isoenzymes. Several questions remain. Do all proton pump inhibitors carry the same risks of serious adverse reactions? Which individuals are most susceptible? What are the time courses of individual reactions? What monitoring strategies are best? New drugs for the same indications continue to emerge, including potassium-competitive acid blockers, inhibitors of transient lower esophageal sphincter relaxation, serotonergic agents/prokinetics, mucosal protectants, histamine H3 receptor agonists, anti-gastrin agents, and esophageal pain modulators. Their benefit to harm balance remains to be discovered. Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0718-z
\n \n\n \n \nWe have adapted an established technique for perfusing the isolated, working rat heart to the guinea-pig heart and characterized its biochemical and haemodynamic performance. After 20 min of anoxia the heart recovers about 50% of its pre-anoxic performance ('post-anoxic cardiac failure') and after 90 min of continuous work total cardiac output falls to 50% of its initial, stable value ('spontaneous cardiac failure'). We have studied the effects of digoxin (10-7 M and 2 \u00d7 10-7 M) and dopamine (10-5 M) on these two forms of cardiac failure and shown that digoxin improves the haemodynamic performance of the heart without altering its metabolism and therefore increases its efficiency. In contrast dopamine improves the haemodynamic performance of the heart at the expense of increased aerobic and anaerobic metabolism. The preparation is of value in studying the effects of cardioactive drugs on hearts subjected to constant pre-load and after-load. \u00a9 1982.
\n \n\n \n \nThere is a multiplicity of potassium channels in nervous tissue. These have been characterized on the basis of their electrophysiological actions but more information is required on their structures and on the functions of the different subtypes of channel in different parts of the nervous system. We currently also lack drugs which are specific in opening or closing individual subtypes of channel. However, when more is known about the structure and function of these channels and when more specific modulators of their activity are available, it is likely that the use of such compounds may be of great value in the treatment of a variety of conditions affecting the nervous system, including epilepsy, the damage due to cerebral anoxia, neurodegenerative disorders and demyelinating disorders.
\n \n\n \n \nWe define an adverse drug reaction as \"an appreciably harmful or unpleasant reaction, resulting from an intervention related to the use of a medicinal product, which predicts hazard from future administration and warrants prevention or specific treatment, or alteration of the dosage regimen, or withdrawal of the product.\" Such reactions are currently reported by use of WHO's Adverse Reaction Terminology, which will eventually become a subset of the International Classification of Diseases. Adverse drug reactions are classified into six types (with mnemonics): dose-related (Augmented), non-dose-related (Bizarre), dose-related and time-related (Chronic), time-related (Delayed), withdrawal (End of use), and failure of therapy (Failure). Timing, the pattern of illness, the results of investigations, and rechallenge can help attribute causality to a suspected adverse drug reaction. Management includes withdrawal of the drug if possible and specific treatment of its effects. Suspected adverse drug reactions should be reported. Surveillance methods can detect reactions and prove associations.
\n \n\n \n \nThe BM1A EB-virus transformed human lymphocyte cell line contains approximately 950 000 Na+/K+-ATPase sites per cell. The turnover number of each site is approx. 2240 molecules of rubidium per min. When cells are exposed to a low extracellular concentration of potassium the intracellular concentration of sodium rises, and the cells respond in the short term by increasing the Vmax of 86Rb+ uptake. In the longer term the cells respond by increasing both the Vmax of 86Rb+ uptake and the Bmax of [3H]ouabain binding. The suggestion that increases in the intracellular concentration of sodium is responsible for these changes is supported by the finding that monensin, which increases intracellular sodium without affecting intracellular potassium, is capable of inducing both the short- and long-term changes associated with a low external concentration of potassium. \u00a9 1990.
\n \n\n \n \nBackground: Deliberate self-poisoning with yellow oleander seeds is common in Sri Lanka and is associated with severe cardiac toxicity and a mortality rate of about 10%. Specialised treatment with antidigoxin Fab fragments and temporary cardiac pacing is expensive and not widely available. Multiple-dose activated charcoal binds cardiac glycosides in the gut lumen and promotes their elimination. We aimed to assess the efficacy of multiple-dose activated charcoal in the treatment of patients with yellow-oleander poisoning. Methods: On admission, participants received one dose of activated charcoal and were then randomly assigned either 50 g of activated charcoal every 6 h for 3 days or sterile water as placebo. A standard treatment protocol was used in all patients. We monitored cardiac rhythm and did 12-lead electocardiographs as needed. Death was the primary endpoint, and secondary endpoints were life-threatening cardiac arrhythmias, dose of atropine used, need for cardiac pacing, admission to intensive care, and number of days in hospital. Analysis was by intention to treat. Findings: 201 patients received multiple-dose activated charcoal and 200 placebo. There were fewer deaths in the treatment group (five [2.5%] vs 16 [8%]; percentage difference 5.5%; 95% CI 0.6-10.3; p=0.025), and we noted difference in favour of the treatment group for all secondary endpoints, apart from number of days in hospital. The drug was safe and well tolerated. Interpretation: Multiple-dose activated charcoal is effective in reducing deaths and life-threatening cardiac arrhythmias after yellow oleander poisoning and should be considered in all patients. Use of activated charcoal could reduce the cost of treatment.
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