Association between gabapentinoids and oedema treated with loop diuretics: A pooled sequence symmetry analysis from the USA and Denmark.

AIMS: To assess the gabapentinoid-oedema-loop diuretic prescribing cascade in adults using large administrative health care databases from the USA and Denmark. METHODS: This study used a sequence symmetry analysis to assess loop diuretic initiation before and after the initiation of gabapentinoids among patients aged 20 years or older without heart failure or chronic kidney disease. Data from MarketScan Commercial and Medicare Supplemental Claims databases (2005 to 2019) and Danish National Prescription Register (2005 to 2018) were analyzed. Use of loop diuretics associated with initiation of selective norepinephrine reuptake inhibitors (SNRI) was used as a negative control. We assessed the pooled temporality of loop diuretic initiation relative to gabapentinoid or SNRI initiation across the 2 countries. Secular trend-adjusted sequence ratios (aSRs) with 95% confidence intervals (CIs) were calculated using data from 90 days before and after initiation of gabapentinoids. Pooled ratio of aSRs were calculated by comparing gabapentinoids to SNRIs. RESULTS: Among the 1 511 493 gabapentinoid initiators (Denmark [n = 338 941]; USA [n = 1 172 552]), 20 139 patients had a new loop diuretic prescription 90 days before or after gabapentinoid initiation, resulting in a pooled aSR of 1.33 (95% CI 1.06-1.67). The pooled aSR for the negative control (i.e., SNRI) was 0.84 (95% CI 0.75-0.94), which resulted in a pooled ratio of aSRs of 1.58 (95% CI 1.23-2.04). Pooled estimated incidence of the gabapentinoid-loop diuretic prescribing cascade was 8.14 (95% CI, 1.92-34.49) events per 1000 patient-years. CONCLUSION: We identified evidence of the gabapentinoid-oedema-loop diuretic prescribing cascade in 2 countries.

Magnitude of and Characteristics Associated With the Treatment of Calcium Channel Blocker-Induced Lower-Extremity Edema With Loop Diuretics.

Importance: Calcium channel blockers, specifically dihydropyridine calcium channel blockers (DH CCBs, eg, amlodipine), may cause lower-extremity edema. Anecdotal reports suggest this may result in a prescribing cascade, where DH CCB-induced edema is treated with loop diuretics. Objective: To assess the magnitude and characteristics of the DH CCB prescribing cascade. Design, Setting, and Participants: This cohort study used a prescription sequence symmetry analysis to assess loop diuretic initiation before and after the initiation of DH CCBs among patients aged 20 years or older without heart failure. Data from a private insurance claims database from 2005 to 2017 was analyzed. Use of loop diuretics associated with initiation of angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and other commonly used medications was used as negative controls. Data were analyzed from March 2019 through October 2019. Exposures: Initiation of DH CCB or negative control medications. Main Outcomes and Measures: The temporality of loop diuretic initiation relative to DH CCB or negative control initiation. Secular trend-adjusted sequence ratios (aSRs) with 95% CIs were calculated using data from 360 days before and after initiation of DH CCBs. Results: Among 1 206 093 DH CCB initiators, 55 818 patients (4.6%) (33 100 [59.3%] aged <65 years; 32 916 [59.0%] women) had a new loop diuretic prescription 360 days before or after DH CCB initiation, resulting in an aSR of 1.87 (95% CI, 1.84-1.90). An estimated 1.44% of DH CCB initiators experienced the prescribing cascade. The aSR was disproportionately higher among DH CCB initiators who were prescribed high doses (aSR, 2.20; 95% CI, 2.13-2.27), initiated amlodipine (aSR, 1.89; 95% CI, 1.86-1.93), were men (aSR, 1.96; 95% CI, 1.91-2.01), and used fewer antihypertensive classes (aSR, 2.55; 95% CI, 2.47-2.64). The evaluation of ACE inhibitors or ARBs as negative controls suggested hypertension progression may have tempered the incidence of the prescribing cascade (aSR for ACE inhibitors and ARBs, 1.27; 95% CI, 1.24-1.29). Conclusions and Relevance: This study found an excessive use of loop diuretics following initiation of DH CCBs that cannot be completely explained by secular trends or hypertension progression. The prescribing cascade was more pronounced among those initially prescribed a high dose of DH CCBs.