Evaluation of a Common Prescribing Cascade of Calcium Channel Blockers and Diuretics in Older Adults With Hypertension

Canadian population-based cohort study of older adults found that being newly dispensed a calcium channel blocker was linked to statistically significantly higher rate of being subsequently dispensed a loop diuretic within 90 days vs. 2 groups who starting other antihypertensives

SPS commentary:

A commentary discusses why these prescribing cascades occur given clinicians’ familiarity with these common drug classes. It suggests that drug-induced symptoms frequently go underreported and when reported are often misattributed as the manifestation of new disease, in part because clinicians do not routinely ask about medication adverse effects, and this error may be amplified by episodic care and a lack of clinician continuity. It notes that even when symptoms are recognized as possibly associated with a medication, some clinicians may apply a shotgun approach of pursuing multiple strategies to diagnose and resolve a new problem at once rather than systematically excluding medication-associated symptoms before moving on to new treatments or tests. A shotgun approach to new lower extremity oedema might include ordering a new medication to treat the symptom (loop diuretic), stopping the potentially offending medication, and ordering diagnostic testing to rule out alternative causes. Furthermore, the initial prescribing cascade can set off many other negative consequences, including adverse drug events, potentially avoidable diagnostic testing, and hospitalisations. It also points out that antihypertensives may be a trigger and consequence of prescribing cascades, as many commonly used medications may raise BP, thus, patients with polypharmacy are at heightened risk of being exposed to series of prescribing cascades if their current use of medications is not carefully discussed before the decision to add a new antihypertensive. It concludes that identifying prescribing cascades and their consequences is an important step to stem the tide of polypharmacy and inform deprescribing efforts.


JAMA Internal Medicine

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