Zyvox Study Shows Increased Risk of Death in Patients With Gram-Negative Infections

Results from a recent open-label study showed that Pfizer's antibiotic Zyvox increased the risk of death in patients with Gram-negative, catheter-related infections, according to an FDA MedWatch report issued March 16.

The study compared Zyvox (linezolid) with the older antibiotics vancomycin, oxacillin and dicloxacillin in seriously ill patients with catheter-related bloodstream infections, including catheter-site infections, according to the FDA.

"Patients treated with linezolid had a higher chance of death than did patients treated with any comparator antibiotic, and the chance of death was related to the type of organism causing the infection," the FDA said.

Although patients with Gram-positive infections showed no difference in mortality, higher mortality rates were associated when Gram-negative bacteria were present, or in subjects without an infection upon study enrollment, the FDA said.

Pfizer recently added a warning to the Zyvox U.S. label for a "mortality imbalance." "Linezolid is not approved and should not be used for the treatment of patients with catheter-related bloodstream infections or catheter-site infections," the label states.