Background: Gabapentinoids (gabapentin and pregabalin) are commonly prescribed medications typically used to treat neuropathic pain. They are often prescribed off label with varying degrees of evidence to treat a variety of other conditions such as non-neuropathic pain, post-operative pain, and alcohol use disorder. Due to emerging evidence, in 2019 the FDA put out a warning regarding the increased risk of respiratory depression and death when taking gabapentinoids along with other CNS depressants or in patients with obstructive lung disease. Minimal data exist about the use of gabapentinoids in hospitalized patients, a population who often receive CNS depressant medications such as opioids and benzodiazepines. This study seeks to describe the prescription patterns of gabapentinoids in hospitalized, non-surgical, adult patients and evaluate for common complications.
Methods: This is a retrospective cohort study of adult patients admitted to a general medicine service at a tertiary care hospital in the United States during January 2022. Data were extracted directly from the electronic medical record and managed using REDCap electronic data capture tools. Primary outcomes included determining the prevalence of and indications for gabapentinoid prescription, rates of prescription to patients with obstructive lung disease, and rates of co-prescription with opioids and benzodiazepines. Secondary outcomes included rates of respiratory failure, encephalopathy, falls, death, and length of stay (LOS). Student’s t-test was used to compare means between the groups, while relative risks were calculated to compare categorical outcomes.
Results: Of the 150 patients included in the study, 36 (24%) received gabapentinoids in the hospital (9 of which were new scripts). Only 3 of 36 (8.3%) patients received a gabapentinoid for an FDA approved indication, although this increased to 10 (27.8%) when expanding gabapentin’s indications to include those of pregabalin. Fifteen of the 36 (41.7%) patients received a benzodiazepine and 24 (66.7%) received an opiate, which is an increase from pre-hospital rates of co-prescription (16.1% and 38.7%). In the hospital, the gabapentinoid group had a higher relative risk of receiving a benzodiazepine (RR 1.9, 95% CI 1.13, 3.19) or opiate (RR 1.65, 95% CI 1.20, 2.28), but there was no difference in rates of obstructive lung disease (33.3% vs 31.6%, RR 1.06, 95% CI 0.62, 1.80). There was no difference in LOS nor the relative risks of death, falling, or developing encephalopathy, although the relative risk of developing respiratory failure was lower in the gabapentinoid group (RR 0.38, 95% CI 0.16, 0.88). The relative risk of 30-day post discharge readmissions, deaths, and documented falls was not statistically different.
Conclusions: Gabapentinoids are commonly prescribed medications in the hospital. During admission, gabapentinoids are frequently co-prescribed with CNS depressing medications as well as prescribed to patients with obstructive lung disease, both of which are known risk factors for respiratory depression and death. In addition, patients receiving gabapentinoids were independently more likely to be prescribed benzodiazepines and opiates. This study did not find any significant associations between gabapentinoid use and the secondary outcomes of death, falls, LOS, and readmissions, but it is currently underpowered to find small differences.