Drug Safety
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The traditional view of opioids held that the individual opioid agonists shared the same mechanism of action, differing only in their potency and pharmacokinetic properties. However, recent advances in opioid receptor pharmacology have made this view obsolete. Distinguishing features of the synthetic opioid agonists are related, at least in part, to variation in affinity and intrinsic efficacy at multiple opioid receptors. ⋯ The systemic absorption of morphine after intrathecal or epidural administration is very slow, resulting in long duration of analgesia and low plasma concentrations, while lipid-soluble opioids are rapidly absorbed into the circulation and redistributed to the brain. The serotonin syndrome may result from coadministration of pethidine, dextromethorphan, pentazocine or tramadol with monoamine oxidase inhibitors (MAOIs) or selective serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors (SSRIs). There are clinically important interactions between opioids and hypnosedatives, resulting in synergistic effects on sedation, breathing and blood pressure.
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Review Comparative Study
Comparative tolerability profile of hypertensive crisis treatments.
Hypertensive crisis is defined as a severe elevation in BP and is classified as either urgency or emergency. In hypertensive urgency there is no end-organ injury and no evidence that acute BP lowering is beneficial. Indeed, rapid uncontrolled pressure reduction may be harmful. ⋯ There are few, if any, comparative or randomised trials providing definitive conclusions about the efficacy and safety of comparative agents. Some investigators recommend decreasing the diastolic BP to no less than 100 to 110 mm Hg. A reasonable approach for most patients with hypertensive emergencies is to lower the mean arterial pressure by 25% over the initial 2 to 4 hours with the most specific antihypertensive regimen.
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Nausea and vomiting are both common in early pregnancy. Most cases are mild and do not require treatment. However, persistent vomiting and severe nausea can progress to hyperemesis if the woman is unable to maintain adequate hydration, and fluid and electrolyte as well as nutritional status are jeopardised. ⋯ If inadequately or inappropriately treated, it may cause Wernicke's encephalopathy, central pontine myelinolysis and death. In extreme cases, women may request, or their obstetricians recommend, termination of the pregnancy. There are uncontrolled data supporting a beneficial effect of corticosteroids in these women, and a randomised placebo-controlled trial is currently in progress.
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Paroxysmal supraventricular tachycardia caused by atrioventricular re-entry is the most frequent arrhythmia in children of all age groups. It represents the most frequent clinical situation where antiarrhythmic drug therapy has to be considered in a child. Acute termination of an episode of tachycardia in all paediatric age groups is nowadays best achieved with an intravenous bolus injection of adenosine. ⋯ However, in infants and smaller children, ablation is used as a last resort. Rare forms of paediatric supraventricular tachycardia (other than atrioventricular re-entry through the atrioventricular node or accessory pathways) are occasionally difficult to treat and present special problems. For each of these arrhythmias, a specially tailored individual therapeutic approach is needed.
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Meta Analysis
A meta-analysis to assess the incidence of adverse effects associated with the transdermal nicotine patch.
To estimate the frequency of adverse effects associated with the use of the transdermal nicotine patch, we abstracted and analysed data from 47 reports of 35 clinical trials. The meta-analysis presented here represents a synthesis of data from 41 groups of nicotine patch recipients totalling 5501 patients, and 33 groups of placebo recipients totalling 3752 patients. Smoking abstinence was the primary outcome in 32 of the trials, and relief of colitis symptoms was the primary outcome in 2 of the trials; 1 study of contact sensitisation was included in the skin irritation analysis. ⋯ The incidence of nausea or vomiting appeared to be lowest when the patch dose was tapered. The results of this meta-analysis indicate that very large studies would be needed to assess the effect of the patch, if any, on serious, rare outcomes. These results also suggest that the rate of minor adverse effects might be lowered by modifying patch-use protocols.