Orthostatic blood pressure recovery in older males using alpha-blockers for lower urinary tract symptoms, an explorative study in a urology outpatient clinic.

Abstract

Alpha-blockers have been associated with orthostatic hypotension (OH). We aimed to assess the prevalence of OH measured with beat-to-beat blood pressure monitoring in older male outpatients who used alpha-blockers for lower urinary tract symptoms (LUTS). In addition, we investigated associations of OH with duration of alpha-blocker use, concomitant medication use and comorbidity. Cross-sectional explorative study in a urology outpatient clinic. Older white males ≥65 years using alpha-blockers for LUTS were included. Blood pressure responses to standing up from supine were recorded using a validated beat-to-beat blood pressure device (Finapres). Prevalence rates were derived from the beat-to-beat data to include OH measured between 60-110 s (OH), impaired recovery OH at 40 s (OH[40]), initial OH (IOH) and normal orthostatic response. Subgroups were defined based on duration of alpha-blocker use, polypharmacy, and Charlson comorbidity index (CCI), to obtain relative risks. Sixty-five patients were included. Median age was 75 years (range 65-92). The prevalence of OH was 7.7% (n=5). The prevalence of OH(40) was 16.9% (n=11) and of IOH 38.5% (n=25). Thirty-six patients (55.4%) had a normal orthostatic response. The relative risk of OH for the subgroup using 10 medications (n=13) was 6.0 (95%CI 1.1-32.3). For the subgroup with multimorbidity (CCI ≥3, n=11) this was 7.4 (95%CI 1.4-39.0). Recent initiation of alpha-blocker use (<3 months) did not increase OH risk (RR 0.6 [95%CI 0.1-5.1]). The overall prevalence of OH was low and comparable to age-matched population prevalence, suggesting that the relative contribution of alpha-blockers to OH was small. However, OH risk significantly increased in patients with multimorbidity or polypharmacy. For these patients, the benefits of starting alpha-blockers for LUTS should be weighed against the increased risk of OH.