By Dennis Thompson
A commonly prescribed muscle relaxant known as baclofen can leave older kidney patients so disoriented that they land in the hospital, a new study warns.
“It can present with acute stroke-like symptoms, even though it’s not a stroke,” said senior researcher Dr. Amit Garg, a professor of nephrology at Western University in Ontario, Canada. “It can present with dementia-like symptoms.”
About 1 in 25 people with low kidney function prescribed high doses of baclofen wound up being admitted to a hospital for severe confusion, according to a study of nearly 16,000 older Canadians with chronic kidney disease.
By comparison, only one in 500 kidney patients not prescribed baclofen wound up hospitalized for confusion.
“There was a pretty marked difference in risk,” Garg said, noting that these findings “highlight a potential risk associated with these drugs that hasn’t been fully appreciated.”
Other seniors might also face this risk, since kidney function often declines as people grow older, he added.
Baclofen is typically prescribed to people suffering muscle spasms, Garg said. Doctors hand out more than 8 million prescriptions of baclofen every year. It’s sold under a number of different brand names, including Lioresal, Gablofen and Kemstro.
The drug leaves the body when the kidneys filter it out of a person’s blood, Garg explained.
“If someone’s kidney function isn’t working very well, that means the drug is accumulating in the system,” he said.
Garg and other doctors had started noticing that kidney patients on baclofen sometimes became disoriented and dazed.
The researchers pulled health data on nearly 16,000 older Ontario residents with chronic kidney disease who had been prescribed baclofen between 2007 and 2018.
The investigators compared those patients’ hospitalizations for mental conditions against those from a group of almost 300,000 kidney patients who’d not been prescribed the drug.
Patients were at greatest risk of hospitalization for confusion if their kidney function was very impaired — 30% or less — and they had been prescribed a high dose of baclofen, more than 20 milligrams (mg) per day.
But even patients with kidney function as high as 60% had an increased risk of confusion when prescribed high doses of baclofen, the findings showed. About 1 in 5 older adults live with kidney function of less than 60%.
Kidney patients prescribed baclofen at 20 mg/day or higher had nearly 20 times the relative risk of being hospitalized for an altered mental state, compared with patients not taking the drug, the researchers found.
Doses lower than 20 mg/day were associated with a nearly sixfold increase in kidney patients’ risk of hospitalization.
The results were published online Nov. 9 in the Journal of the American Medical Association, to coincide with a planned presentation at the American Society of Nephrology annual meeting, in Washington, D.C.
Dr. Teresa Murray Amato, director of geriatric emergency medicine at Northwell Health in New Hyde Park, N.Y., stated:
“All patients should speak to their doctors regarding side effects of all medications. For patients over 65, make sure you understand your kidney function and ask about potential renal dosing on all medications. If you are on baclofen now, make sure you contact your health care provider so that you can have an expedited conversation.”
“Please seek emergency care if you or your family member is showing any signs of altered [mental activity] and you suspect medications may be involved,” Murray Amato said.
Regulatory agencies also might consider strengthening the drug warning for baclofen to include this potential effect, Garg said.
Saturday, Nov. 9, 2019 (HealthDay News)
For more information:
The U.S. National Library of Medicine has more about baclofen.
SOURCES: Amit Garg, M.D., Ph.D., professor, nephrology, Western University, Ontario, Canada; Holly Koncicki, M.D., associate professor, Icahn School of Medicine at Mount Sinai, New York City; Teresa Murray Amato, M.D., director geriatric emergency medicine, Northwell Health, New Hyde Park, N.Y., and chair, emergency medicine, Long Island Jewish Forest Hills, N.Y.; Nov. 9, 2019, Journal of the American Medical Association, online; Nov. 9, 2019, presentation, American Society of Nephrology annual meeting, Washington, D.C.