New Treatment for Dangerous Staphyloccocal Infections

An international clinical trial has proved the effectiveness and safety of a new drug for treating bloodstream and heart infections caused by Staphylococcus aureus bacteria.

Researchers at the Duke University Medical Center (Durham, NC, USA) tested the effectiveness and safety of a drug called daptomycin for the treatment of endocarditis and bacteremia, caused by S aureus. A randomized, controlled trial enrolled 246 patients with bacteremia--with or without endocarditis--from 44 centers in four countries. Patients were randomly assigned to one of two treatment groups.

The first group received 6 mg of daptomycin per kilogram of body weight, administered intravenously once daily. The second group received standard antibiotic therapy, which consisted of an initial four-day course of gentamicin plus a full course of either an antistaphylococcal penicillin or vancomycin, depending on bacterial susceptibilities. Results showed that daptomycin was more successful than standard therapy at eliminating drug-resistant S aureus, showing a 44.4% success rate versus 31.8%. However, the standard therapy slightly outperformed daptomycin for S aureus without drug resistance, at 48% success versus 44%. Daptomycin proved safer to the kidneys than standard therapy. The findings were published in the August 17, 2006, issue of the New England Journal of Medicine.

Treating S aureus infections is difficult because many strains have developed resistance to all penicillin-related antibiotics. For these highly resistant strains, called methicillin-resistant S aureus (MRSA), vancomycin has been the only consistently reliable treatment alternative. Recently, however, MRSA strains with resistance to vancomycin have appeared.

"This is the first new drug the FDA has approved in two decades for treating these types of potentially life-threatening infections,” said Dr. Vance G. Fowler, Jr., an associate professor of infectious diseases who participated in the study. "This advance adds a new weapon to our dwindling arsenal of antibiotics against these difficult-to-treat infections.”

Daptomycin, made by Cubist Pharmaceuticals (Lexington, MA, USA) was approved by the U.S. Food and Drug Administration (FDA) in 2003 for treating skin infections caused by S aureus.



Related Links:
Duke University Medical Center
Cubist Pharmaceuticals