Drug Safety
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The widespread practice of using a lower plasma paracetamol (acetaminophen) concentration threshold for the treatment of paracetamol poisoning in patients with chronic alcoholism has been introduced on the basis of anecdotal case reports. In animals, acute alcohol loading inhibits toxic metabolic activation of paracetamol whilst chronic alcohol administration results in cytochrome P450 (CYP) 2E1 induction with increased toxic metabolic activation of paracetamol by CYP2E1 and increased hepatotoxicity. However, due to species differences in CYP expression, activity and induction, it is not possible extrapolate the results of these animal studies to clinical situations in humans. ⋯ Whilst it is possible that chronic exposure to excessive amounts of alcohol does predispose patients with paracetamol overdose to hepatotoxicity, a critical review of the literature reveals that the evidence to date does not support this. A prospective, controlled study is required. On the basis of the scientific evidence to date, use of the 100 line for patients with chronic alcoholism, in countries where the 200 line represents the standard treatment line, is unjustified.
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Comparative Study
Cardiac and CNS toxicity of levobupivacaine: strengths of evidence for advantage over bupivacaine.
Bupivacaine is currently the most widely used long-acting local anaesthetic. Its uses include surgery and obstetrics; however, it has been associated with potentially fatal cardiotoxicity, particularly when given intravascularly by accident. Levobupivacaine, a single enantiomer of bupivacaine, has recently been introduced as a new long-acting local anaesthetic with a potentially reduced toxicity compared with bupivacaine. ⋯ This may be due to a lack of perceived safety benefit and/or consideration of the additional costs that are associated with switching to levobupivacaine, which is approximately 57% more expensive than bupivacaine. If the price of levobupivacaine were closer to bupivacaine then the argument to switch to levobupivacaine would undoubtedly be much stronger. With the continued clinical use of levobupivacaine the database available to make comparisons will increase and this may allow cost-benefit arguments to be made more forcefully for levobupivacaine in the future.
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The mercury-based vaccine preservative thiomersal has come under scrutiny in recent months because of its presence in certain vaccines that provide the foundation of childhood immunisation schedules. Over the past decade new vaccines have been added to the recommended childhood schedule, and the relatively smaller bodyweight of infants has led to concern that the cumulative exposure of mercury from infant vaccines may exceed certain guidelines for the human consumption of mercury. In the US, government agencies and professional societies have recently recommended that thiomersal be removed altogether from vaccines. ⋯ This apparent divergence of opinion has left healthcare professionals and the public with uncertainty about the potential health effects from low level exposure to thiomersal as well as the necessity of removing thiomersal from vaccines. At present, scientific investigation has not found conclusive evidence of harm from thiomersal in vaccines. As a precautionary measure, efforts are under way to remove or replace thiomersal from vaccines and providers should anticipate the availability of more vaccine products that are thiomersal-free over the coming years.
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Adverse events and medical errors affecting patient care are recognised internationally as major problems in medicine. The failure of health care professionals and health institutes to address this problem has threatened to undermine public confidence in the health care system as a whole. Less focus has been directed at the ethical issues raised by negative outcomes of care, specifically the issue of disclosure. ⋯ Healthcare institutions should provide training for the clinicians in this area, if necessary. As a general rule, patients should be informed of unexpected adverse incidents as soon as possible. Medical staff should be rewarded for adverse event reporting and protected from institutional retaliation on account of errors made in health care.
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The complications of failure, neural injury and local anaesthetic toxicity are common to all regional anaesthesia techniques, and individual techniques are associated with specific complications. All potential candidates for regional anaesthesia should be thoroughly evaluated and informed of potential complications. If there is significant risk of injury, then these techniques should be avoided. ⋯ Prompt diagnosis, immediate cardiopulmonary resuscitation and aggressive vasopressor therapy with epinephrine (adrenaline) are required. New complications of regional anaesthesia emerge occasionally, e.g. cauda equina syndrome with chloroprocaine, microspinal catheters and 5% hyperbaric lidocaine, and epidural haematoma formation in association with low molecular weight heparin. Even so, after 100 years of experience, most discerning physicians appreciate the benefits of regional anaesthesia.