Study: Allergy remedy loratadine shows promise for Lyme disease

PORTOLA VALLEY, Calif. — A new study funded by the Bay Area Lyme Foundation and conducted by Stanford School of Medicine researchers has found that loratadine — the active ingredient in Bayer's Claritin, a common antihistamine frequently taken to treat allergy symptoms — may be able to help kill Borrelia burgdorferi, the bacteria associated with Lyme disease. Lyme disease is a potentially debilitating condition with 300,000 new cases in the United States each year. The study was published in the Open Access publication Drug Design, Development and Therapy.

 

"Our results bring us closer to the possibility of discovering the first targeted therapy to treat Lyme disease," said Jayakumar Rajadas, director, Biomaterials and Advanced Drug Delivery Lab, Stanford School of Medicine, and lead author of the study. "It's exciting to see first-hand that our insights into the metabolic activity of this elusive bacteria may give us the ability to actually kill it."

 

The results of this new laboratory study show that loratadine and specifically its metabolite, desloratadine, are able to prevent manganese from entering the cell wall of the bacteria that causes Lyme disease, starving the bacteria and causing it to die in test tubes. The antihistamine accomplishes this by inhibiting the bacteria's transport system, BmtA (Borrelia metal transporter A). 

 

Manganese is required for certain metabolic processes of Borrelia burgdorferi and also plays an important role in numerous biological processes in the human body. Previous research shows that in general, bacteria scavenge the body for trace metals that circulate in the blood and have developed special adaptations on their cell walls to internalize these metals. These adaptations are called transport proteins, and BmtA is the specialized transport protein for Borrelia burgdorferi. BmtA binds with manganese to bring it into the bacteria, and studies have shown that BmtA and manganese are required to make the bacteria harmful to the human body.

 

"Because current treatments do not work for everyone and the bacteria that causes Lyme disease offers many treatment challenges, this study offers encouraging insights for researchers, and hope for the 80 million Americans at risk of getting Lyme disease," said Bonnie Crater, founder and Science Committee Chairperson, Bay Area Lyme Foundation. "We are grateful to the BioADD team for their commitment to finding solutions to this difficult disease."

 

Currently, patients with Lyme disease are typically prescribed a two to four week course of antibiotics, but approximately 10% to 20% of patients treated with this regimen will have lingering symptoms of fatigue, pain or joint and muscle aches.