The incidence of diuretic associated consecutive prescribing cascades

Abstract

Background A prescribing cascade occurs when adverse drug reactions (ADRs) caused by one medication (index) are misinterpreted as a new medical condition, inducing the prescription of another medication (marker). Prescribing cascades can result in polypharmacy and impact patients’ quality of life. While individual prescribing cascades with one index and one marker medication are well-studied, little is known about consecutive prescribing cascades with a secondary marker following a primary marker. This study explores the feasibility of analysing consecutive prescribing cascades involving diuretics as primary markers by determining their incidence.

Methods This retrospective cohort study used the Clinical Practice Research Datalink (CPRD) to identify patients aged ≥65 years who were newly prescribed diuretics as the primary marker within 12 months after the first prescription of a calcium channel blocker or gabapentinoid (index) between 2018-2022. Incidence was determined for the following secondary markers: antigout medications, urinary frequency and incontinence medications, and potassium salts and potassium-sparing agents within 12 months after diuretic prescription.

Results Between 2018-2022, 608,225 new index users were identified, of whom 28,240 patients were prescribed a primary marker. Of these, 1,877 (6.6%) were prescribed a secondary marker within 12 months. Antigout medications were prescribed for 311 patients (1.1%), urinary frequency and incontinence medications for 518 patients (1.8%), and potassium salts or potassium-sparing agents for 1,090 (3.7%) patients.

Conclusions This study demonstrates that a substantial number of patients may be exposed to consecutive prescribing cascades involving a diuretic as a primary marker. This underscores the importance of improved recognition and prevention of ADRs.