Prescrire international
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Inhaled antimuscarinic drugs have modest symptomatic efficacy in patients with chronic obstructive pulmonary disease (COPD). They also have several atropinic adverse effects, including mydriasis, visual disorders, dry mouth, constipation, micturition difficulties and tachycardia. In March 2008, the US Food and Drug Administration reported an increased frequency of stroke in COPD patients receiving tiotropium in clinical trials. ⋯ A trial published after this metaanalysis, the Uplift study, including 5993 COPD patients followed for 4 years, showed no statistically significant difference in the frequency of cardiovascular death, myocardial infarction or stroke in the inhaled tiotropium group compared with the placebo group. However, these results are not sufficient to dispel the strong suspicion of an increased risk of cardiovascular adverse effects. In practice, the use of an inhaled antimuscarinic drug should be discussed on a case by case basis, weighing the only modest benefits against the worrisome risk of cardiovascular events.
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This review examines whether the use of automated external defibrillators by first-responders improves the survival of adults who suffer cardiopulmonary arrest. We also examined the risks associated with these devices, based on a review of the literature using the standard Prescrire methodology. Automated external defibrillators detect ventricular fibrillation with almost perfect sensitivity and specificity. ⋯ In the United States, about 1 in 5 functioned over a 10-year period, mainly due to electrical or software problems. In summary, automated external defibrillators have a favourable risk-benefit balance, at least in trained hands. Specific training helps first-responders to act purposefully and without delay, and to implement the chain of survival until medical help arrives.