A population-based cohort study of linked health administrative databases in Ontario shows that older adults had increased serious adverse events (SAEs) when initiation of calcium channel blocker (CCB) therapy was followed within 3 months by a diuretic prescription. “Our study raises awareness of the downstream impact of the CCB–diuretic prescribing cascade at a population level and provides an opportunity for clinicians who identify this prescribing cascade to review their patients’ medications to determine if they can be optimized,” the authors conclude.
Included in the analysis were community-dwelling adults, 66 years of age or older with hypertension and no history of heart failure (HF) or diuretic use in the prior year. Individuals receiving an initial prescription for CCBs who were subsequently dispensed a diuretic within 90 days were the prescribing cascade group, and those not dispensed a diuretic were classified as the nonprescribing cascade group. Based on a primary outcome of an SAE (composite of emergency department visits and hospitalizations in the 90-day follow-up period), the investigators found: “Among 39,347 older adults with hypertension and no history of HF who were newly dispensed a CCB, 1881 (4.8%) had a new diuretic dispensed within 90 days after CCB initiation. Compared to the non-prescribing cascade group, those in the prescribing cascade group had higher rates of SAEs (HR: 1.21, 95% CI: 1.02–1.43).”