Repurposed UTI drug can treat deadly brain-eating amoeba

A recent case study has revealed that a decade-old medicine for urinary tract infections (UTIs) may effectively treat a rare brain infection caused by an amoeba called Balamuthia mandrillaris, reported by Science magazine.

The 54-year-old patient was initially admitted to a Northern California hospital for an unexplained seizure. After undergoing magnetic resonance imaging (MRI), doctors found a mass on the left side of his brain that appeared to be surrounded by swelling.

He was then transferred to the University of California San Francisco (UCSF) Medical Center, where samples of his brain tissue and clear fluid were taken and analyzed. The results showed that the man was infected with a rare brain-eating amoeba.

Brain-eating Amoeba treated using UTI drug

B. mandrillaris is a single-celled organism that lives in dust, soil, and water. It can penetrate human skin or be inhaled into the lungs, leading to a rare and often fatal brain infection known as granulomatous amebic encephalitis.

The infection is extremely rare but often fatal. According to the Centers for Disease Control and Prevention (CDC), there have been only 200 cases of B. mandrillaris worldwide. The infection claims the lives of 90 percent of infected individuals.

The doctors at UCSF initially suggested an extensive prescription of antiparasitic, antibiotic, and antifungal medications to treat the patient. "It's what's recommended because it was what happened to be used in patients who survived," Dr. Natasha Spottiswoode, an infectious disease physician-scientist at UCSF and first author of the case report, told Science.

However, the treatment backfired. The patient experienced significant adverse effects from the treatment, including renal failure, without showing any improvement in his condition.

In search of another solution, Dr. Spottiswoode dug up a 2018 report published in the journal mBio, in which UCSF scientists found evidence that an antibiotic called nitroxoline can kill the brain-eating amoeba in laboratory settings.

The drug has been used as an oral treatment for UTIs for years. However, it is only approved in Europe and not in the U.S. Spottiswoode, and her team needed permission from the Food and Drug Administration to use it.

After receiving the approval, the team started the patient on nitroxoline and observed rapid improvement within a week. His brain lesions shrank, and he was soon discharged from the hospital.

Repurposing this UTI drug provides hope for individuals affected by this rare and fatal condition. Currently, UCSF doctors are overseeing the case of a second B. mandrillaris-infected patient who's started receiving nitroxoline, and the initial results are encouraging, Science reported.