Antidepressants that inhibit neuronal norepinephrine reuptake are not associated with increased spontaneous reporting of cardiomyopathy.

A recent literature review linked norepinephrinergic stimulation to alterations in cyclic adenosine monophosphate (cAMP)-mediated signaling in cardiac myocytes and suggested that this might contribute to the pathological mechanisms that lead to chamber enlargement and hypocontractility, which are seen in dilated cardiomyopathy. This accompanies a large body of literature linking cardiac sympathetic outflow activation in early heart failure with progressive myocyte deterioration. As the mode of action of a number of antidepressants involves the inhibition of neuronal norepinephrine reuptake to varying degrees, this study was conducted to assess whether such agents might be associated with disproportionate reporting of cardiomyopathy. Limited data exist specifically examining the association between the antidepressant use and the cardiomyopathy. Using a data mining algorithm (DMA), we quantitatively investigated the association between antidepressant agents that predominantly exert their effects through inhibiting neuronal norepinephrine reuptake (rather than serotonin) and cardiomyopathy. We retrospectively applied a Bayesian DMA, the Bayesian Confidence Propagation Neural Network, to the cumulative reports in the Food and Drug Administration Adverse Event Reporting System (through the fourth quarter of 2006) and World Health Organization Vigibase (through the second quarter of 2007) databases. A threshold of the posterior interval 95% lower limit > 0 was used to define a signal of disproportionate reporting with individual or groups of antidepressants and cardiomyopathy-related terms. The analysis suggested that there is no direct relationship between antidepressants with greater norepinephrine reuptake inhibitor activity (affinity for norepinephrine reuptake transporter or selectivity for norepinephrine versus serotonin) and reporting of cardiomyopathy. In contrast, an inverse correlation might exist with a higher number of cases identified with tricyclic antidepressants showing lower norepinephrine reuptake inhibition and the serotonin/norepinephrine reuptake inhibitors as well as with serotonin/ norepinephrine/slight dopamine reuptake inhibitor.

Time-to-signal comparison for drug safety data-mining algorithms vs. traditional signaling criteria.

Data mining may improve identification of signals, but its incremental utility is in question. The objective of this study was to compare associations highlighted by data mining vs. those highlighted through the use of traditional decision rules. In the case of 29 drugs, we used US Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) data to compare three data-mining algorithms (DMAs) with two traditional decision rules: (i) N >or= 3 reports for a designated medical event (DME) and (ii) any event comprising >2% of reports in relation to a drug. Data-mining methods produced 101-324 signals vs. 1,051 for the N >or= 3 rule but yielded a higher proportion of signals having publication support. For the 2% rule, the fraction of signals having publication support was similar to that associated with data mining. Data-mining signals lagged N >or= 3 signaling by 1.5-11.0 months. It may therefore be concluded that data mining identifies fewer signals than the "N >or= 3 DME" rule. The signals appear later with data mining but are more often supported by publications. In the case of the 2% rule, no such difference in publication support was observed.

Decision support methods for the detection of adverse events in post-marketing data.

Spontaneous reporting is a crucial component of post-marketing drug safety surveillance despite its significant limitations. The size and complexity of some spontaneous reporting system databases represent a challenge for drug safety professionals who traditionally have relied heavily on the scientific and clinical acumen of the prepared mind. Computer algorithms that calculate statistical measures of reporting frequency for huge numbers of drug-event combinations are increasingly used to support pharamcovigilance analysts screening large spontaneous reporting system databases. After an overview of pharmacovigilance and spontaneous reporting systems, we discuss the theory and application of contemporary computer algorithms in regular use, those under development, and the practical considerations involved in the implementation of computer algorithms within a comprehensive and holistic drug safety signal detection program.

Cyclosporine neurotoxicity.

A comprehensive search of the published literature was undertaken to identify reports providing patient-specific data relating to adverse neurologic events with cyclosporine. References cited in the articles identified by the search were manually reviewed to ensure that articles were pertinent. Studies and case reports on cyclosporine neurotoxicity in which individualized patient data were provided were included for review and analysis. Information pertaining to all aspects of cyclosporine neurotoxicity, including epidemiology, clinical manifestations, postulated mechanisms, and management implications, was evaluated. Estimates from case series suggest a 0.5-35% frequency of the disorder. Risk factors include supratherapeutic blood concentrations of cyclosporine, and pharmacokinetic and pharmacodynamic drug interactions, hypocholesterolemia, and other metabolic abnormalities. Postulated mechanisms include a vasculopathy based on cyclosporine's effect on endothelial cell synthesis of prostaglandin, and release and uptake of endothelin as well as inhibition of mitochondrial steroid 26-hydroxylase. Reported adverse events involved all levels of the neuraxis. Associated abnormalities include elevated cerebrospinal fluid protein and pleocytosis, various electroencephalogram abnormalities, and characteristic neuroimaging findings. In most patients these events were reversible with dosage reduction or withdrawal of therapy. Many reports described positive rechallenge, and in rare instances the events regressed despite continuing or reintroducing the drug.

Multiple cholesterol emboli syndrome--six cases identified through the spontaneous reporting system.

Six cases of suspected multiple cholesterol emboli syndrome were identified by a review of reports contained in the company's records of adverse event reports. Antecedent risk factors in these reports included cardiac catheterization, thrombolytic therapy, translumbar aortography, renal arteriography, subclavian arteriography, abdominal aortography, and heparinization. Unlike the commonly reported subacute presentation, onset occurred during or immediately after catheterization in 5 of the 6 patients reported. Acute renal failure; hypertension; back, leg, and/or abdominal pain; and livedo reticularis were the events most frequently reported. Angiographers should consider multiple cholesterol embolization when multiple organ system dysfunction occurs during or immediately after intraarterial catheterization.