Nephrologist Leads Efforts to Tout Drug’s Dangers

Baclofen can cause toxicity in patients with decreased kidney function

Illustration of kidney

Baclofen, an anti-spasmodic drug, can cause serious neurological changes such as altered mental status, coma, and death in patients with decreased kidney function. This can occur because it’s primarily excreted via the kidneys and accumulates in the body when kidney function is severely diminished or absent.

Despite the potentially adverse effects in these patients, many physicians aren’t aware of baclofen’s dangers, says Matthew Sparks, MD, a Duke nephrologist who is leading efforts along with John Roberts, MD, a nephrology colleague, to raise awareness. “If one person takes baclofen and dies or has a significant adverse outcome, that’s enough to make clinician education worthwhile,” Sparks says.

After Sparks and his colleagues began seeing more hospitalized patients with baclofen toxicity, they reported a case series about five of them. More recently, they wrote a teaching case discussing the potential harms in prescribing baclofen to patients with diminished kidney function.

Since then, he has collaborated with a research group led by Kenar Jhaveri, MD, at Hofstra University/Northwell in New York to examine patients with diminished kidney function, defined as an estimated glomerular filtration rate less than 30, who took baclofen.

“We’re each doing a chart review of these patients,” he says. At Duke, about 100 out of 71,000 hospitalized patients took baclofen during 2017 and experienced diminished kidney function. His team is analyzing this data.

Their goal is to publish these findings of the joint study with Hofstra/Northwell in a general internal medicine journal to reach primary care physicians who typically prescribe baclofen. “When I see a patient with decreased kidney function taking baclofen, it’s usually too late, because the effects of its toxicity have already occurred,” Sparks says.

Several other tactics have been adopted to improve the warning about baclofen. The teams’ efforts include creating electronic medical record alerts to inform prescribers about risks and creating buttons for residents, emergency physicians, and nephrology fellows to wear that spell out the warning: “No Baclofen in CKD & ESRD” (chronic kidney disease and end stage renal disease). Sparks and colleagues have also launched a social media campaign to educate physicians outside of Duke.

A global database offering current clinical guidelines that is used as a reference by physicians cited Sparks’ case series when revising guidelines for baclofen dosing. “Research is making headway into changing baclofen prescribing practices,” he says.

Sparks has also been successful in prompting the American College of Physicians’ Medical Knowledge Self-Assessment Program to remove inaccurate statements from test questions that fail to recommend baclofen be dose-adjusted or stopped in patients with diminished kidney function.

“We need to continue to educate clinicians about this problem,” Sparks said. “The goal is to provide more evidence to further establish the link between adverse neurological effects in patients with diminished kidney function taking baclofen. If clinicians see data like ours that quantifies the problem, I believe they will be more likely to change their prescribing habits.”