IMPORTANCE Calcium channel blockers (CCBs) are commonly prescribed agents for hypertension that can cause peripheral edema. A prescribing cascade occurs when the edema is misinterpreted as a new medical condition and a diuretic is subsequently prescribed to treat the edema. The extent to which this prescribing cascade occurs at a population level is not well understood.OBJECTIVE To measure the association between being newly dispensed a CCB and subsequent dispensing of a loop diuretic in older adults with hypertension. DESIGN, SETTING, AND PARTICIPANTSA population-based cohort study was performed using linked health administrative databases of community-dwelling adults 66 years or older with hypertension and new prescription drug claims from September 30, 2011, to September 30, 2016 The dates of analysis were September 1, 2018, to May 30, 2019.EXPOSURES Individuals who were newly dispensed a CCB were compared with the following 2 groups: (1) individuals who were newly dispensed an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker and (2) individuals who were newly dispensed an unrelated medication. MAIN OUTCOMES AND MEASURESHazard ratios (HRs) with 95% CIs were estimated for individuals who were dispensed a loop diuretic within 90 days of follow-up using Cox proportional hazards regression models. RESULTSThe cohort included 41 086 older adults (Ն66 years) with hypertension who were newly dispensed a CCB, 66 494 individuals who were newly dispensed another antihypertensive medication, and 231 439 individuals who were newly dispensed an unrelated medication. At index (ie, the dispensing date), the mean (SD) age was 74.5 (6.9) years, and 191 685 (56.5%) were women. Individuals who were newly dispensed a CCB had a higher cumulative incidence at 90 days of being dispensed a loop diuretic than individuals in both control groups (1.4% vs 0.7% and 0.5%, P < .001). After adjustment, individuals who were newly dispensed a CCB had increased relative rates of being dispensed a loop diuretic compared with individuals who were newly dispensed an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker (HR, 1.68; 95% CI, 1.38-2.05 in the first 30 days after index [days 1-30]; 2.26; 95% CI, 1.76-2.92 in the subsequent 30 days [days 31-60]; and 2.40; 95% CI, 1.84-3.13 in the third month of follow-up [days 61-90]) and individuals who were newly dispensed unrelated medications (HR, 2.51; 95% CI, 2.13-2.96 for 1-30 days after index; 2.99; 95% CI, 2.43-3.69 for 31-60 days after index; and 3.89; 95% CI, 3.11-4.87 for 61-90 days after index). This association persisted, although slightly attenuated, from 90 days to up to 1 year of follow-up and when restricted to a subgroup of individuals who were newly dispensed amlodipine.CONCLUSIONS AND RELEVANCE Many older adults with hypertension who are newly dispensed a CCB subsequently receive a loop diuretic. Given how widely CCBs are prescribed, interventions are needed to raise clinicians' awareness of this common prescribing cascade to reduce the ...

As originally defined, the term “prescribing cascade” describes a sequence of events that begins when an adverse drug event (ADE) occurs, is misinterpreted as a new medical condition, and a subsequent drug is then inadvertently prescribed to treat the new condition. We refine the definition to encompass both recognized and unrecognized ADEs because they can both contribute to problematic prescribing practices. In addition, we discuss that although prescribing cascades are most commonly viewed as problematic, they may be appropriate and therapeutically beneficial in certain clinical situations. We differentiate between appropriate and problematic prescribing cascades by adopting a similar approach to the framework proposed in the highly acclaimed King's Fund report Polypharmacy and Medicines Optimization. Practical considerations are also presented to aid clinicians in preventing the propagation of problematic prescribing cascades within their clinical practice. Providing new perspectives on the scope and appropriateness of the prescribing cascade concept is an important step in describing clinically relevant cascades and in encouraging safe prescribing practices. J Am Geriatr Soc 67:1023–1026, 2019.

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