Loop diuretics and subsequent use of urinary symptom medications in older adults: evaluation of a possible prescribing cascade.

Background: Loop diuretic (LD) use may lead to a prescribing cascade whereby urinary symptoms are ascribed to genitourinary syndromes and treated with urinary symptom medications (USMs). We investigated if LDs lead to increased USM use among older adults and whether this potential prescribing cascade varies across key characteristics.

Methods: This was a prescription sequence symmetry analysis of Veterans Administration data, involving veterans ≥66 years who initiated treatment with LD (2010-2019). USMs were antimuscarinics, beta-3 adrenergic agonists, peripheral alpha-1 blockers, and 5-alpha reductase inhibitors. We calculated the adjusted sequence ratio (aSR), assessing the cascade signal while adjusting for secular trends, and stratified by key variables.

Results: There were 17 735 veterans who initiated USM within 6 months after LD and 25 190 who initiated USM within 6 months before LD; 99% were male. Unexpectedly, the aSR was 0.74 (95% CI, 0.73-0.76), meaning patients were 26% less likely to initiate USM within 6 months after initiating LD versus 6 months before. This inverse relationship held in men (aSR, 0.74, 95% CI, 0.72-0.76) but was null in women (aSR, 1.00, 95% CI, 0.80-1.26). In men without baseline urinary symptoms, we observed the LD-USM cascade in patients with heart failure (aSR 1.52, 95% CI, 1.41-1.63) and multimorbidity (eg, Charlson fourth quartile, aSR 1.24, 95% CI, 1.10-1.39).

Conclusions: We did not find evidence for an LD-USM cascade among predominantly male older adults overall. Clinicians may underprescribe USMs in patients receiving LDs, perhaps due to strong attribution of urinary symptoms to LD use.