News Briefs

Falsely elevated glucose readings, warns FDA

The FDA has notified pharmacists, physicians, nurses, medical technologists, pharmacists, and other health care professionals of the potential for life-threatening falsely elevated glucose readings in patients who have received parenteral products containing maltose or galactose, or oral xylose, and are subsequently tested using glucose dehydrogenase pyrroloquinoline quinone (GDH-PQQ) based glucose monitoring systems. There have been reports of the inappropriate administration of insulin and consequent life-threatening/fatal hypoglycemia in response to erroneous test results obtained from patients receiving parenteral products containing maltose. Cases of true hypoglycemia can go untreated if the hypoglycemic state is masked by false elevation of glucose readings.

For more information, see www.fda.gov/medwatch/safety/2005/safety05.htm#maltose. A preliminary listing of U.S. products that may cause glucose test interference is provided.

FDA warning: Adverse events with rFVIIa

Novo Nordisk and the FDA have notified health care professionals of revisions to the Warnings and Adverse Reactions sections of the prescribing information for recombinant human coagulation Factor VIIa (rFVIIa) (NovoSeven). The revisions provide updated safety information on thrombotic and thromboembolic adverse events, based on clinical studies in nonhemophilia patients and on post-marketing safety surveillance. A clinical study in elderly, nonhemophiliac, intracerebral hemorrhage patients indicated a potential increased risk of arterial thromboembolic adverse events with use of rFVIIa, including myocardial ischemia, myocardial infarction, cerebral ischemia and/or infarction.

For more information, see www.fda.gov/medwatch/safety/2005/safety05.htm#NovoSeven.

ASHP provides reference to Consumer Reports guide

The American Society of Health-System Pharmacists has provided a drug reference guide to the Consumer Reports Medical Guide, a subscription-based on-line tool designed to provide "independent, trustworthy information on best treatments and prescription drugs."

This searchable Drug Reports is supported by Patient’s Guides to 900 name-brand and generic medicines, including the top 200 most-prescribed medications. The reports contain comparative, unbiased, evaluative information about drug safety and efficacy that is developed independently by pharmacists and other medication experts and based on a foundation of clinical evidence, according to Consumer Reports.

www.ConsumerReportsMedicalGuide.org includes 60 of the most common and serious medical conditions, including asthma in children, diabetes, high blood pressure, and obesity, and expected to add more conditions soon. The information has sections explaining how each condition is diagnosed, what symptoms manifest, rate of occurrence, what to expect, what treatments are available, and specific questions to ask a doctor.

Recent topics on the web site include "needless surgeries" that can be avoided, and depression in children.

FDA approves updated labeling for Lexiva

GlaxoSmithKline (GSK) and Vertex Pharmaceuticals have announced that the FDA has approved GSK’s application to add clinical data to the prescribing information for fosamprenavir calcium (Lexiva), an HIV protease inhibitor (PI).

The newly added information shows that simultaneous administration of fosamprenavir calcium in combination with esomeprazole (Nexium) does not result in lowering of blood levels for fosamprenavir calcium. This update is based on a study showing that blood levels of fosamprenavir calcium remained unchanged when patients took fosamprenavir calcium and 20 mg once-daily esomeprazole simultaneously. Drug interactions that result in lower PI blood levels may increase the risk for virologic failure in patients treated with HIV protease inhibitors.

Fosamprenavir calcium is indicated for the treatment of HIV infection in adults in combination with other antiretroviral medications. The companies say the following points should be considered when initiating therapy with fosamprenavir calcium plus ritonavir (RTV) (Lexiva/r) in PI-experienced patients: The PI-experienced patient study was not large enough to reach a definitive conclusion that Lexiva/r and lopinavir/ritonavir are clinically equivalent. Once-daily administration of fosamprenavir calcium plus RTV is not recommended for PI-experienced patients.

Fosamprenavir calcium is the first PI to offer flexible dosing options with no food or fluid restrictions.

Red cell aplasia, severe anemia linked to drug

Amgen, Ortho Biotech, and the FDA have notified health care professionals of revision to the Warnings, Precautions, Adverse Reactions, and Dosage and Administration sections of the prescribing information for darbepoetin alfa (Aranesp), epoetin alfa (Epogen), and epoetin alfa (Procrit). The revised labeling provides updated safety information on reports of pure red cell aplasia and severe anemia, with or without other cytopenias, associated with neutralizing antibodies to erythropoietin in patients treated with these products. This has been reported predominantly in patients with chronic renal failure receiving these products by subcutaneous administration. Recommendations for evaluation and treatment are provided in the new prescribing information.

For more information, see www.fda.gov/medwatch/safety/2005/safety05.htm#aranesp2 and www.fda.gov/medwatch/safety/2005/safety05.htm#epoetin.