Drug-safety alerts issued by regulatory authorities: usefulness of meta-analysis in predicting risks earlier

Seguimiento e impacto de la divulgación de cinco alertas sanitarias de medicamentos en Colombia

Objetivo Realizar la notificación y verificar el seguimiento de cinco alertas sanitarias de medicamentos a un grupo de prestadores de salud en Colombia.Métodos Estudio cuasi-experimental, prospectivo, antes y después, sin grupo control, mediante una intervención en médicos prescriptores de ketoconazol, metoclopramida, nimesulida, diacereina, ranelato de estroncio. Se tomó como población universo a los afiliados al régimen contributivo del Sistema de Salud Colombiano en 13 entidades promotoras de salud (EPS) de Colombia. Se identificaron los pacientes que recibían mensualmente estos medicamentos previamente a la alerta. Se realizó una intervención educativa y posteriormente se midió la proporción de cambio en la dispensación.Resultados Se realizaron en total unas 26 actividades diferentes a 500 médicos prescriptores. De un total de 4 121 954 de personas se identificaron 13 979 pacientes mensuales en 2013 que recibían alguno de los cinco medicamentos y se observó una reducción en 1 470 sujetos al mes (-10,5%) para 2014. El medicamento con el que se consiguió la mayor reducción fue ketoconazol (-31,1% de casos), seguido de ranelato de estroncio (-30,3%) y metoclopramida (-8,6%). Para nimesulida (+0,7%) y diacereina (+16,4%) no se obtuvieron resultados favorables.Conclusiones Se mantienen prescripciones potencialmente riesgosas en pacientes de Colombia. Con intervenciones basadas en farmacovigilancia posterior al reporte de alertas por agencias reguladoras sanitarias, se puede disminuir la proporción de pacientes que utilizan estos medicamentos.

Postmarketing Safety Events Relating to New Drugs Approved in Brazil Between 2003 and 2013: A Retrospective Cohort Study

This study investigated postmarketing safety events (PMSEs) for new drugs approved in Brazil and evaluated whether a range of drug characteristics influenced the time between approval and the first PMSE. This retrospective study included new drugs registered between 2003 and 2013 by the National Health Surveillance Agency (ANVISA), which is responsible for medicines approval in Brazil. PMSEs were defined as any drug safety alert or drug withdrawal from the market. The existence of risk evaluation and mitigation strategies (REMS) by the US Food and Drug Administration (FDA) and Brazil were recorded. A Kaplan-Meier survival curve of the period between the date of ANVISA registration and the PMSE was calculated. We found a statistically significant difference between the time to PMSE for drugs with an FDA REMS compared with those without a REMS, with a log rank value (Mantel Cox) of 0.002. There was no association between the time to PMSE and the other drug characteristics investigated. This study demonstrated that the frequency of PMSEs for new drugs approved by ANVISA was statistically associated with the existence of an FDA REMS. The time between approval and first PMSE was shorter for drugs with an FDA REMS, and this finding may contribute to improved awareness of the risk/benefit balance required to ensure continued safe and effective use of new drugs.

Testing the usefulness of the number needed to treat to be harmed (NNTH) in benefit-risk evaluations: case study with medicines withdrawn from the European market due to safety reasons

OBJECTIVE

To explore the usefulness of number needed to treat to be harmed (NNTH), in benefit-risk assessments, by studying the agreement between NNTH values and withdrawals of medicines from European market due to safety reasons.

METHODS

Medicines with data from longitudinal studies were included. Studies were identified from European Medicines Agency's Reports. Meta-analyses were performed to pool odds ratios (OR) with 95% confidence-intervals (CI). Published control event rates were applied to ORs to calculate NNTHs (95%CI) for selected adverse events.

RESULTS

NNTH (95%CI) decreased from pre- to post-marketing for the eight medicines included: peripheral neuropathy (∞ vs. 12[non-significant; NS] with almitrine; heart valve disease with benfluorex (∞ vs. NNTH ranging from 7[4-13] to 7[5-9]); myopathy (-4096[NS] vs. 797[421-1690]), new-onset diabetes (113[NS] vs. 390[425-778]), bleeding (∞ vs. 517[317-1153]), and infection (∞ vs. 253[164-463]) with niacin-laropiprant; psychiatric disorders (12[7-34] vs. 9[5-24]) with rimonabant; myocardial infarction (MI) [-1305 vs. 270[89-4362]) with rofecoxib; MI (-510 vs. NNTH ranging from 152[55-4003] to 568[344-1350]) with rosiglitazone; cardiovascular events (∞ vs. 245[129-1318]) with sibutramine; and liver injury (∞ vs. 5957[NS]) with ximelagatran.

CONCLUSION

NNTH have potential of use as a supportive tool in benefit-risk re-evaluations of medicines and may help regulators to making decisions on drug safety.

A systematic review and meta-analysis of the association between systemic fluoroquinolones and retinal detachment

PURPOSE

Several pharmacoepidemiologic studies have been carried out evaluating the risk of retinal detachment associated with systemic fluoroquinolones. This meta-analysis aims to investigate such association, in the light of the best scientific evidence available.

METHODS

A literature search was conducted to identify relevant studies evaluating the risk for retinal detachment associated with systemic fluoroquinolones. A meta-analysis was performed to pool rate ratios (RRs). Meta-regressions were conducted aiming to evaluate the influence of time interval between fluoroquinolones use and retinal detachment diagnosis or treatment risk estimates.

RESULTS

Ten observational studies from seven publications were included. Overall, fluoroquinolones were not associated with an increased risk for retinal detachment [RR 1.47 (95% CI 0.95-2.27): p = 0.09; I(2)  = 92.8%]. When the analysis was stratified according to different study designs, the result was statistically significant for retrospective cohort studies [RR 1.87 (95% CI 1.36-2.58); p < 0.001; I(2)  = 0.0%] and for past users of fluoroquinolones, based on data from case-control studies [RR 1.07 (95% CI 1.01-1.12); p = 0.01; I(2)  = 0.0%]. According to meta-regressions, the risk for retinal detachment did not vary due to different time intervals between fluoroquinolones prescription and retinal detachment occurrence. No statistically significant results were identified among studies evaluating only rhegmatogenous retinal detachments, as well as among studies that evaluated patients not requiring a prior ophthalmologist visit to be included.

CONCLUSIONS

In light of the current available evidence, systemic fluoroquinolones do not seem to be associated with retinal detachment.

Gastroesophageal reflux symptoms do not correlate with objective pH testing after peroral endoscopic myotomy

INTRODUCTION

Peroral endoscopic myotomy (POEM) is an emerging treatment for esophageal achalasia. Postoperative reflux has been found in a significant number of patients, but it is unknown whether subjective reports of reflux correlate with objective pH testing. The purpose of this study was to compare the objective rate of reflux with standardized reflux symptom scales after POEM. Our hypothesis was that subjective symptoms would not correlate with objective measurement of reflux.

METHODS AND PROCEDURES

Data on all patients undergoing POEM were collected prospectively between August 2012 and June 2014 and included demographics, objective testing (48-h pH probe, manometry, endoscopy), as well as gastroesophageal reflux disease health-related quality of life (GERD-HRQL), GERD symptom scale (GERSS), and antacid use.

RESULTS

Forty-three patients underwent POEM during the study period. The mean age was 53.5 ± 17.4 years with a BMI of 29.6 ± 8.4 kg/m(2), and 27 (63%) were male. Forty-two patients (98%) completed at least 6 months of follow-up, and 26 (60%) underwent repeat pH measurement. Dysphagia scores improved from 4 (0-5) at baseline to 0 (0-3) (p < 0.001). On follow-up pH testing, 11 (42%) were normal and 15 (58%) had elevated DeMeester scores. Postoperative GERSS or GERD-HRQL scores did not correlate with DeMeester scores on Spearman's rank-order tests (r = 0.02, p = 0.93 and r = 0.04, p = 0.50, respectively). Postoperative PPI use was not significantly associated with normal or abnormal pH testing: 5 of 7 (71%) patients who were taking PPIs postoperatively had abnormal DeMeester scores compared to 9 of 18 (50%) of patients who were not taking PPIs (p = 0.332).

CONCLUSIONS

Peroral endoscopic myotomy provides excellent dysphagia relief for patients with achalasia, but is associated with a high rate of reflux on pH testing postoperatively. Subjective symptoms are not a reliable indicator of postoperative reflux. Routine pH testing should be considered in all patients following POEM.