Predictors of a Gabapentinoid–Loop‐Diuretic Prescribing Cascade in U.S. Nursing Home Residents

Background Gabapentinoid‐related peripheral edema may prompt loop diuretic prescribing. Nursing home (NH) residents may be especially prone to this prescribing cascade. We estimated the incidence and identified predictors of the gabapentinoid‐loop diuretic prescribing cascade in NHs. Methods We conducted a retrospective cohort study using 2016–2022 Medicare claims linked with Minimum Data Set assessments. We identified residents aged ≥ 66 years who initiated gabapentinoids in NHs and who had no evidence of loop diuretic use, heart failure, or renal insufficiency during the prior 6 months. The outcome was loop diuretic initiation within 90 days of gabapentinoid initiation. Using multivariable Poisson regression models, we estimated adjusted risk ratios (aRR) with 95% robust confidence intervals to identify predictors. We used pooled logistic regression models to examine the relationship between time‐varying gabapentinoid dose and loop diuretic initiation risk. Results Among 23,544 residents, 994 (4.2%) experienced a prescribing cascade at a median of 36 days (IQR 15–61) after gabapentinoid initiation. Risk was higher with age 86–90 years (aRR = 1.60) or ≥ 91 years (aRR = 1.38); a diagnosis of chronic pain or fibromyalgia (aRR = 1.16), or diabetes (aRR = 1.23); and receipt of potassium‐sparing diuretics (aRR = 1.53), thiazide diuretics (aRR = 1.27), or 15 or more unique medications (aRR = 1.18). Higher (versus lower) weekly gabapentin dose during follow‐up was associated with a 1.45 times higher prescribing cascade risk over 13 weeks. Those with Alzheimer's Disease and Related Dementias (aRR = 0.79), or moderate (aRR = 0.72) to severe cognitive impairment (aRR = 0.59) had a lower risk versus those with intact cognition. Conclusions Approximately 1 in 20 NH residents who initiate gabapentinoids receives a loop diuretic within 3 months. Potentially modifiable predictors included existing polypharmacy and titrating gabapentinoid doses. NH clinicians should monitor for edema soon after gabapentinoid initiation and consider dose reductions or discontinuation before adding a loop diuretic.