(HealthDay News) — The incidence of encephalopathy is increased with prescription of higher versus lower doses of baclofen among older patients with chronic kidney disease (CKD), according to a study published online Nov. 9 in the Journal of the American Medical Association. The research was published to coincide with Kidney Week, the annual meeting of the American Society of Nephrology, held from Nov. 5 to 10 in Washington, DC.

Flory T. Muanda, MD, PhD, from the Institute for Clinical Evaluative Services in London, Ontario, Canada, and colleagues compared the 30-day incidence of encephalopathy among 15,942 older adults (≥66 years) with CKD prescribed baclofen at a dose of either ≥20 mg/day or <20 mg/day (61 and 39%, respectively).

The researchers found that hospitalization with encephalopathy occurred in 1.11 and 0.42% of patients who started baclofen at ≥20 mg/day and <20 mg/day, respectively (weighted risk ratio [RR], 3.54 [95% confidence interval (CI), 2.24 to 5.59]; weighted risk difference [RD], 0.80% [95% CI, 0.55 to 1.04%]). In a subgroup analysis, there was a progressive increase in absolute risk at lower estimated glomerular filtration rate (eGFR; weighted RD: eGFR 45 to 59: 0.42% [95% CI, 0.19 to 0.64%]; eGFR 30 to 44: 1.23% [95% CI, 0.62 to 1.84%]; eGFR <30: 2.90% [95% CI, 1.30 to 4.49%). In a secondary comparison with 284,263 nonusers, the risk for encephalopathy was significantly higher for both groups of baclofen users (≥20 mg/day: weighted RR, 19.8 [95% CI, 14.0 to 28.0]; <20 mg/day: weighted RR, 5.90 [95% CI, 3.59 to 9.70]).

“This population-based study of 15,942 older adults confirms and extends the findings of 30 international case reports linking baclofen use with encephalopathy in patients with CKD,” the authors write.

One author disclosed financial ties to the pharmaceutical industry.

Reference

Muanda FT, Weir MA, Bathini L, et al. Association of Baclofen With Encephalopathy in Patients With Chronic Kidney Disease [published online November 9, 2019]. JAMA. doi:10.1001/jama.2019.17725