Perioperative gabapentin increased the risk of delirium, new antipsychotic drug use, and pneumonia in older adults after major surgery, a retrospective study found.
The risk of delirium – the primary outcome of the study – was 3.4% for elderly patients who received gabapentin within 2 days of major surgery and 2.6% for those who did not, with a relative risk (RR) of 1.28 (95% CI 1.23-1.34), Dae Hyun Kim, MD, ScD, of Brigham & Women’s Hospital and Hebrew SeniorLife in Boston, and colleagues reported.
The risk of using new antipsychotics was 0.8% versus 0.7% (RR 1.17, 95% CI 1.07-1.29), respectively, and the risk of pneumonia was 1.3% versus 1. 2% (RR 1.11 95% CI 1.03-1.20), the investigators reported in JAMA Internal Medicine.
“Gabapentin is increasingly being used for postoperative pain relief to reduce opioid use, although previous research has suggested that the analgesic effect of gabapentin is not as great,” Kim said. MedPage today.
“In our clinical experience with the geriatric service, we’ve seen several patients who developed delirium after major surgery and those patients were given gabapentin,” he noted. “We conducted this study to see if patients who received gabapentin after surgery were more likely to develop delirium than those who did not receive gabapentin.”
“Our findings suggest that routine use of gabapentin for postoperative pain management should be avoided,” Kim added. “Prescribing requires a careful risk-benefit assessment.”
Poorly controlled postoperative pain is associated with several complications, including cognitive impairment, delirium, depression, reduced mobility and longer recovery, observed Zachary Marcum, PharmD, PhD, of the University of Washington in Seattle, and co-authors, in an accompanying editorial.
“Multimodal pain management in the perioperative period is important to minimize the short- and long-term morbidity associated with opioid use,” the editors wrote.
But this study “adds to growing evidence that gabapentin as part of a multimodal pain management approach in the perioperative period is not ideal in older adults because it increases the risk of harm with unclear benefits in this population,” Marcum and co-authors noted. “While taking gabapentin may reduce pain and conserve opioids in younger populations, the risks do not seem to outweigh the benefits in older adults.”
The findings are “a call to surgical associations and verification programs that aim to improve surgical care in older adults to specifically address the use of gabapentin in consensus statements, including a clear statement of the currently known risks and benefits,” the findings wrote. editors. “More globally, this new clinical evidence invites us to rethink multimodal pain management pathways for older adults, which require data-driven non-opioid pain management strategies that can be translated into everyday clinical practice.”
Kim and colleagues studied diagnostic codes for patients in the Premier Healthcare Database age 65 or older who had major surgery in U.S. hospitals within 7 days of hospitalization from January 2009 to March 2018, and were not taking gabapentin before surgery.
Of the 967,547 patients, 119,087 (12.3%) used perioperative gabapentin within 2 days of surgery. The researchers’ propensity score corresponded to 118,936 gabapentin users and an equal number of non-users. The mean age was 74.5 years and 62.7% were female.
Between postoperative day 3 and hospital discharge, the risk of adverse events was lower in gabapentin users before the propensity score was matched, but increased risks of delirium, new antipsychotic drug use and pneumonia were observed in gabapentin users in the matched cohorts.
After matching, the risk differences between gabapentin users and non-users were 0.75 per 100 individuals for delirium, 0.12 per 100 individuals for new antipsychotic use and 0.13 per 100 individuals for pneumonia. There was no increased risk of hospital death.
The incidence of delirium in this study was lower than previously reported incidences after surgery of 15% to 25% because of the low sensitivity and high specificity of the study’s delirium identification algorithm, Kim and co-authors noted.
“In addition, the diagnosis codes for delirium and pneumonia did not have an exact start date in our data sets, so these results may have been present in some patients before surgery,” the researchers acknowledged.
This study was supported by grants from the National Institute on Aging.
Kim reported personal benefits from Alosa Health and VillageMD and grants from NIH; co-authors reported grants from NIH.
Marcum has made no mention of a conflict of interest; a co-author reported relationships with the American Heart Association, the American College of Cardiology, Boston Pepper Center and the National Institute on Aging.