Could Claritin Cure Lyme Disease?

An OTC allergy medication may be able to kill the bacteria behind Lyme disease, bringing researchers closer to developing the first targeted therapy for the debilitating infection.

Since Lyme-causing Borrelia burgdorferi survive on manganese (Mn), researchers from the Stanford University School of Medicine hypothesized that blocking the bacteria’s Mn transport protein, Borrelia metal transporter A (BmtA), would starve the bacteria and ultimately help cure the infection.

Among a shortlist of FDA-approved compounds that could potentially bind to the BmtA structure, the investigators determined that the antihistamine loratadine (Claritin)—and specifically its metabolite, desloratadine—were able to inhibit Mn from entering the cell walls of Borrelia, causing the bacteria to die in test tubes.

“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,” said lead study author Jayakumar Rajadas, PhD, in a press release. “…Our results bring us closer to the possibility of discovering the first targeted therapy to treat Lyme disease.”

Approximately 300,000 new cases of Lyme disease occur annually, according to 2013 estimates from the US Centers for Disease Control and Prevention. A 2- to 4-week course of antibiotics is typically prescribed to patients with the infection, but up to 20% of those treated have lingering related symptoms.

“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 of the Bay Area Lyme Foundation, which funded the research published in Drug Design, Development and Therapy.