Category: Professional Posters
Purpose: Dihydropyridine calcium channel blockers (DH-CCBs), a first-line option for treatment of hypertension, can cause lower extremity edema (LEE). Anecdotal reports suggest this may result in a prescribing cascade (PC), where DH-CCB-associated LEE is treated with a loop diuretic (LD). We aimed to assess the magnitude and characteristics of the DH-CCB associated LEE, LD PC (the PC).
Methods: A prescription sequence symmetry analysis (PSSA) was used to assess initiation of LDs before or after initiating DH-CCBs among patients ≥20 years old, without a heart failure (HF) diagnosis using a private insurance claims database from 2005 to 2017. Secular trend-adjusted sequence ratios (aSR) with 95% confidence intervals (CI) were calculated within a 360-day window of the initial DH-CCB claim. The percentage of patients impacted by this PC was estimated by the difference in initial LDs before and after initial DH-CCBs divided by DH-CCB initiators. Patient characteristics and relative rates of the PC were calculated using relative risks (RR) among sub-populations with potentially differential PC risk. The study was exempted from review by the University of Florida Institutional Review Board due to use of deidentified data.
Results: Among the 1,206,093 DH-CCB initiators, 55,818 patients had a new LD prescription within 360 days of initiating DH-CCB, resulting in aSR 1.87 (95% CI 1.84-1.90). An estimated 1.44% of DH-CCB initiators experienced the PC. Older adults (RR 2.01, 95% CI 1.96-2.07) and those initiated on a high dose DH-CCB (RR 2.59, 95% CI 2.46-2.74) were more likely to experience the PC. There was no change in the incidence of PC over the duration of the study period.
Conclusion: The temporality of initial DH-CCB and LD claims further supports the presence of the PC. Although a low percentage of DH-CCB initiators experienced the PC, the number of patients impacted is likely substantial given DH-CCBs’ use in hypertension. Older adults and patients initiated on high dose DH-CCB may be at increased risk for the PC. There were no improvements towards avoiding the PCs over time.