viernes, 20 de abril de 2012

FDA Puts 16 Drugs on Watch List

http://www.medscape.com/viewarticle/762205?src=mp&spon=18

domingo, 15 de abril de 2012

Aspirin for Preventing Colorectal Cancers and Other Solid Tumors

[Long-term effect of aspirin on colorectal cancer incidence and mortality. Lancetabstract | Effect of daily aspirin on long-term risk of death due to cancer: Lancetabstract]

Supplementation with Niacin or [Omega]-3 Fatty Acids Is Ineffective for Secondary Prevention

 [Niacin in patients with low HDL cholesterol levels receiving intensive statin therapy. NEJMabstract |

 Effects of B vitamins and omega 3 fatty acids on CV diseases. Free full-text BMJ article PDF |

n–3 fatty acids and cardiovascular events after myocardial infarction. Free full-text NEJM article PDF]

Selective and Nonselective NSAIDs and Excess CV Risk

These drugs were risky in myocardial infarction patients and were associated with new-onset atrial fibrillation.
The cardiovascular risks of selective cyclooxygenase (COX)-2–blocking nonsteroidal anti-inflammatory drugs (NSAIDs) are well recognized (JW Gen Med Feb 25 2005). Current guidelines also discourage use of nonselective NSAIDs in patients with known cardiovascular disease (CVD), but some clinicians still prescribe these medications, because they believe that short-term use is unlikely to raise risk significantly. To address this issue, Danish investigators took advantage of that country's highly integrated and digitized medical databases, which accurately capture discharge diagnoses and pharmaceutical prescriptions for the entire country.
In a prospective observational study that involved 84,000 patients with first myocardial infarctions (MIs) between 1997 and 2006, 40% of patients suffered recurrent MIs or death, and 42% received NSAIDs at some time. NSAID use was associated with a significant excess risk for recurrent MI or death (hazard ratio, 1.5–1.7, depending on timing and duration of NSAID use after MI). Not surprisingly, risk was high for two COX-2 blockers, rofecoxib (HR, 1.4–2.3) and celecoxib (HR, 1.3–1.9). But, unexpectedly, risk was even higher for the nonselective NSAID diclofenac (HR, 1.7–3.3). Ibuprofen and other nonselective NSAIDs (except naproxen) also were associated with excess risk. This risk became apparent immediately after use for some NSAIDs and within several weeks for most (JW Cardiol Jun 8 2011).
In a case-control study, more than 32,000 patients with initial diagnoses of atrial fibrillation (AF) or flutter between 1999 and 2008 were compared with nearly 326,000 age- and sex-matched controls without AF or flutter. After adjustment for several confounders, risk for AF or flutter was clearly higher with current use of COX-2 blockers (incidence rate ratio, 1.27) and nonselective NSAIDs (IRR, 1.17). Those rates were even higher for NSAID users who had started the medications within 60 days of AF or flutter onset (JW Gen Med Jul 26 2011).
In neither of these studies were investigators able to capture fully and control for all risk factors that could confound the analyses. Nevertheless, the large size of the studies, the inclusion of essentially all cases in the country (i.e., no selection bias), and the quality of the data provide confidence that the results are accurate. The first study did not include patients with known CVD who had not experienced MIs. Nevertheless, the data seem to support current guidelines that discourage NSAID use in patients with CVD. In particular, the data indicate that even short-term use (e.g., for transient musculoskeletal ailments) leads to excess cardiovascular risk

Fuente: Published in Journal Watch General Medicine December 29, 2011

domingo, 1 de abril de 2012

La FDA añade advertencias a la información para prescribir estatinas

(Artículo original en inglés, heartwire; 28 feb. 2012) Silver Spring, EE UU —El tomar una estatina puede incrementar la glucemia y las concentraciones de glucohemoglobina (HbA1c), según los nuevos cambios en la información para prescribir aprobados por la Food and Drug Administration (FDA) hoy día para toda la clase de estos fármacos [1].
Según lo informó heartwire, estudios recientes [2] sobre las conocidas estatinas mostraron un incremento importante del riesgo de diabetes mellitus asociado al tratamiento con altas dosis de estatinas. El estudio Justification for the Use of Statins in Primary Prevention: An Intervention Trial Evaluating Rosuvastatin (JUPITER) mostró un incremento del 27% en los casos de diabetes mellitus en pacientes que tomaban rosuvastatina en comparación con placebo. Así mismo, el subestudio Pravastatin or Atorvastatin Evaluation and Infection Therapy: Thrombolysis In Myocardial Infarction 22 (PROVE-IT TIMI 22) mostró que la atorvastatina en dosis altas puede empeorar el control de la glucemia.
Los nuevos cambios en la información para prescribir aprobados por la FDA también comprenden la posibilidad de que se presenten efectos secundarios cognitivos por lo general leves y reversibles. Además, la información para prescribir lovastatina se ha actualizado en grado importante para incluir contraindicaciones y limitaciones de la dosis del fármaco en pacientes que toman otros medicamentos que pueden aumentar el riesgo de lesión muscular.
La FDA señala que también es importante eliminar la recomendación de que en los pacientes con estatinas se lleve a cabo la vigilancia periódica sistemática de las enzimas hepáticas, pues este enfoque es ineficaz para detectar y evitar las lesiones hepáticas graves "infrecuentes e imprevisibles" relacionadas con las estatinas. El tratamiento con estatinas debe interrumpirse si el paciente muestra signos de lesión hepática importante, hiperbilirrubinemia o ictericia. La información para prescribir ahora señalará que el tratamiento con estatinas no se debiera reiniciar si no se pueden descartar estos fármacos como una causa de los problemas

Fuente: HeartWire