Researchers at Duke Medicine in Durham, NC, have found that a new single-dose antibiotic is as effective as the current standard treatment for methicillin-resistant Staphylococcus aureus, which involves a twice-daily infusion being given for up to 10 days.

A persistent problem with antibiotic resistance is that patients tend to stop taking antibiotics once they feel better. In these instances, it is possible for some bacteria to survive and then grow impervious to the drugs that fight them.

One advantage of the new drug, called oritavancin, is that it has a long half-life, which allows for a single-dose treatment as the drug will continue working to kill bacteria over the whole treatment period.

"Having a single-dose drug could potentially prevent hospitalizations or reduce the amount of time patients would spend in the hospital," says Dr. G. Ralph Corey, lead author of the study.

To test this, researchers conducted a 3-year study of oritavancin, recruiting nearly 2,000 patients across two trials.

Single IV dose as effective as standard treatment

In the first randomized trial, 475 people with stubborn skin infections - including methicillin-resistant Staphylococcus aureus (MRSA) - took this new drug, while 479 people followed the standard treatment - a drug called vancomycin.

Reporting their results in the New England Journal of Medicine, the researchers found that a single intravenous dose of oritavancin was as effective at shrinking the size of the lesion and reducing fever as vancomycin.

The two drugs also reported similar performance in curing infection and reducing the wound area by 20% or more in the first 48-72 hours of treatment.

Fast facts about MRSA
  • People who have a weakened immune system are more at risk from getting serious staph infections, such as MRSA.
  • A study found that wearing gloves or gowns in intensive care units does not reduce overall rates of acquiring MRSA.
  • MRSA infections can be severe if they enter the bloodstream, heart, lungs or other organs.

However, this is not the first trial to find oritavancin effective at killing MRSA. A paper presented by Targanta Therapeutics Corporation at the 47th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy in Chicago, IL, in 2007 also reported success with oritavancin.

Previously, the antibiotic linezolid had also been suggested as a more effective alternative to vancomycin. A 2011 study reported a 76.6% clinical success rate for linezolid as a treatment for MRSA hospital-acquired pneumonia at the end of treatment, whereas a control group receiving vancomycin reported just 57.7% clinical success.

Recently, Medical News Today reported on a study by researchers at the University of Bath, UK, who suggested that by sequencing the genome of MRSA, scientists may be able to predict the severity of infection in an individual.

Determining appropriate treatment options for patients is especially challenging, as the toxicity of the pathogen can vary, which influences the course of the disease. Therefore, this approach would allow physicians to tailor treatment more accurately to individual patients.