New Drugs Could Help Combat Chronic Lyme Disease

Researchers have identified US Food and Drug Administration (FDA)-approved drugs that could help in the fight against post-treatment Lyme disease syndrome (PTLDS).

Venkata Raveendra Pothineni, PhD, at the Stanford University School of Medicine in Stanford, California, and colleagues published the results of their study in the journal Drug Design, Development and Therapy.

“[T]his study has provided a mean[s] to screen a large number of compounds using a highly sensitive, reliable, and rapid platform. The assay has identified a number of FDA-approved drug molecules with their potential to be repurposed for use against both Lyme disease and the associated PTLDS,” the authors write.

Lyme disease—caused by the spirochete Borrelia burgdorferi predominantly—is the most common zoonotic bacterial disease in North America, with an estimated 300,000 or more cases reported annually in the United States alone.

In most patients, antibiotic treatment will completely cure Lyme disease. However, even after appropriate antibiotic treatment, up to 20% of patients with Lyme disease experience long-lasting symptoms, such as muscle and joint pain, fatigue, and problems with memory or concentration. This condition is categorized as PTLDS.

The reason why these symptoms recur in some individuals remains unknown. However, according to the authors, “[s]ome researchers have raised the question that Borrelia may persist in some hosts after antibiotic treatment, but the idea is controversial.”

New drugs that can completely eliminate the causative Borrelia organisms are therefore needed. “In an effort to search for the lead molecules that can potentially be used for clinical application, we developed and used a faster, efficient, and reliable [high-throughput screening] HTS platform for the screening of drug molecules against Borrelia,” the authors write.

In their study, Dr. Pothineni and colleagues tested more than 4,000 drug compounds in the lab for their efficacy against B. burgdorferi. Ultimately, based on the results of their study, they selected the top 20 FDA-approved drugs. They found that these drugs prevented the growth of between 95% and 99.8% of the bacteria in the samples.

Among the identified drugs, the antibiotics erythromycin (which is already used clinically for the treatment of Lyme disease) and kitasamycin seemed to be very active. Anthracycline-based antitumor antibiotics—including epirubicin, doxorubicin, and idarubicin—also significantly blocked bacterial growth. Currently, these drugs are mostly used in the treatment of certain cancers. Of particular interest, disulfiram—an alcohol dehydrogenase inhibitor—was also identified as a potential drug candidate. This drug is primarily used in the treatment of alcohol abuse, although it also has anticancer properties.

The authors emphasized that “[t]he identified compounds can be further investigated for their therapeutic potential in preclinical animal models and in patients with Lyme disease.”

“Moreover, due to the broad variety of molecules, multiple routes of administration and dosage forms can be developed for effectively treating the Lyme disease infections,’ the authors conclude.

Dr. Parry graduated from the University of Liverpool, England in 1997 and is a board-certified veterinary pathologist. After 13 years working in academia, she founded Midwest Veterinary Pathology, LLC where she now works as a private consultant. She is passionate about veterinary education and serves on the Indiana Veterinary Medical Association’s Continuing Education Committee. She regularly writes continuing education articles for veterinary organizations and journals, and has also served on the American College of Veterinary Pathologists’ Examination Committee and Education Committee.