By Tracie White, Stanford University

For decades, the routine treatment for Lyme disease has been standard antibiotics, which usually kill off the infection.

But for up to 20% of people with the tick-borne illness, the antibiotics don’t work. Lingering symptoms of muscle pain, fatigue and cognitive impairment can continue for years — sometimes indefinitely.

A new Stanford Medicine study in lab dishes and mice provides evidence that the drug azlocillin completely kills off the disease-causing bacteria Borrelia burgdorferi at the onset of the illness.

The study suggests it could also be effective for treating patients infected with drug-tolerant bacteria that may cause lingering symptoms.

“This compound is just amazing,” said Jayakumar Rajadas, PhD. He is assistant professor of medicine and director of the Biomaterials and Advanced Drug Delivery Laboratory at the Stanford School of Medicine. “It clears the infection without a lot of side effects. We are hoping to repurpose it as an oral treatment for Lyme disease.”

Rajadas is the senior author of the study, which was published online March 2 in Scientific Reports. The lead author is research associate Venkata Raveendra Pothineni, PhD.

“We have been screening potential drugs for six years,” Pothineni said. “We’ve screened almost 8,000 chemical compounds. We have tested 50 molecules in the dish. The most effective and safest molecules were tested in animal models. Along the way, I’ve met many people suffering with this horrible, lingering disease. Our main goal is to find the best compound for treating patients and stop this disease.”

Hunting for alternative drugs

Frustrated by the lack of treatment options for Lyme disease patients with lingering symptoms, Rajadas and his team began hunting for a better alternative in 2011.

In 2016, they published a study in Drug Design, Development and Therapy that listed 20 chemical compounds, from about 4,000, that were most effective at killing the infection in mice. All 20 had been approved by the Food and Drug Administration for various uses. One, for instance, is used to treat alcohol abuse disorder. (See: What is disulfiram and why is it sparking excitement in the Lyme community?)

In this most recent study, azlocillin, one of the top-20 contenders, was shown to eclipse a total of 7,450 compounds because it is more effective in killing B. burgdorferi and causes fewer side effects.