An evaluation of a potential calcium channel blocker-lower-extremity edema-loop diuretic prescribing cascade.

OBJECTIVES: Dihydropyridine calcium channel blockers (DH-CCB) are associated with lower-extremity edema (LEE). Loop diuretics have been used inappropriately to treat DH-CCB-associated LEE, constituting a prescribing cascade (PC). The aim of this work was to identify the prevalence and factors associated with potential DH-CCB-LEE-loop diuretic PC.

METHODS: The 2014 National Ambulatory Medical Care Survey was used to identify patient visits in which a DH-CCB was continued. The definition of a potential PC was the continuation or initiation of a loop diuretic in the absence of congestive heart failure, cancer, obstructive sleep apnea, chronic kidney disease or end-stage renal disease, obesity, or resistant hypertension. Multivariable logistic regression was used to identify factors related to a potential PC, including demographic information, number of medications, number of patient visits in the previous 12 months, and comorbid conditions.

RESULTS: Among the estimated 47.5 million patient visits in which a DH-CCB was continued, 4.6% had a potential PC. Visits in patients 65 to 84 years of age (odds ratio [OR] 2.56, 95% CI 1.20-5.43) and 85 years of age and older (OR 3.89, 95% CI 1.76-8.61) were more likely to have potential PC compared with patients 18 to 64 years of age. Visits in patients with 5 to 7 (OR 3.75, 95% CI 1.72-8.19), 8 to 11 (OR 2.20, 95% CI 1.09-4.44), and 12 or more (OR 5.23, 95% CI 2.29-11.94) medications were more likely to have potential PC compared with patients with 4 or fewer medications.

CONCLUSION: A potential DH-CCB-associated LEE loop diuretic PC was present in approximately 2.2 million patient visits in which DH-CCB was continued. Older age and an increasing number of concomitant medications were associated with this potential PC.