On Nov. 27, the Pediatric Advisory Committee of the FDA recommended changing the label of the two neuraminidase inhibitors, oseltamivir (Tamiflu) and zanamivir (Relenza), to reflect the potential for neuropsychiatric effects (mostly in children). Last year, Roche revised the oseltamivir label to add warnings of potential confusion and self-injury with the product. According to the FDA, about five patients died as a result of these neuropsychiatric effects, and nearly 600 cases of psychiatric problems were reported.
On Nov. 14, the FDA added to the black box label of rosiglitazone (Avandia) regarding an increased risk of myocardial infarction. The warning states that a recent meta-analysis of 42 clinical studies (mean duration six months, n=14,237) mostly comparing rosiglitazone with placebo, showed it to be associated with an increased risk of myocardial ischemic events. Further, three other studies (mean duration 41 months; n=14,067), comparing rosiglitazone with other oral antidiabetic agents or placebo, have not confirmed or excluded this risk. The available data on the risk of myocardial ischemia are currently inconclusive.
The FDA has asked that GlaxoSmithKline conduct extensive long-term, post-marketing trials to determine rosiglitazone’s cardiovascular safety. A study of this type, is a direct result of the new PDUFA legislation. The trial is expected to begin after July and end by 2014. Updates to the warnings, precautions, and indications sections were also added to the label. For example, rosiglitazone is not recommended for heart disease patients who are taking nitrates, nor is it recommended in combination with insulin.
Finally, the FDA is evaluating postmarketing adverse event reports for varenicline (Chantix) describing suicidal ideation, suicide, and aggressive and erratic behavior in patients taking it for smoking cessation. While the review proceeds, physicians are advised to evaluate patients for behavior and mood disorders, as well as drowsiness. In patients taking varenicline, caution is advised while driving or operating machinery until the patient’s response to it is known. TH
Michele B. Kaufman is a freelance medical writer based in New York City.
References
- Moore TJ, Cohen MJ, Furberg CD. Serious adverse drug events reported to the Food and Drug Administration, 1998-2005. Arch Intern Med. 2007;167:1752-1759.
- Wechsler J. No shortage of recommendations for PDUFA IV as Congress and professional organizations weigh in on drug safety. Formulary 2007;42:264-265.
- Yahav D, Paul M, Fraser A, Sarid N, Leibovici L. Efficacy and safety of cefepime: a systematic review and meta-analysis. Lancet Infect Dis. 2007 May;7(5):338-348.