Orthostatic blood pressure recovery in older males using alpha-blockers for lower urinary tract symptoms

It will ultimately happen to all men as they get older: an enlarged prostate causes problems with urinating. Medication may help relieve these symptoms. So-called alpha-blockers (tamsulosine is a widely used example) can be effective, but may also cause side-effects. In older men, doctors particularly worry about orthostatic hypotension, a drop in blood pressure upon standing up, which may cause dizziness, falls, or syncope.

In this study, led by associate professor in geriatric physiology, Jurgen Claassen (Radboudumc), we investigated if these concerns are justified. We initiated a collaboration between the Geriatrics and Urology departments of Gelre Ziekenhuizen (Apeldoorn) and Radboudumc. For Gelre, geriatician and clinical pharmacologist dr. Petra Spies was the lead investigator. This month, or study was published in the Journal of Clinical Pharmacology and Therapeutics.

We recruited 65 older men (median age 75, range 65 to 92 years) who were using an alpha-blocker for urinary symptom related to an enlarged prostate. We used a research device that can accurately track changes in blood pressure with every heartbeat (Finapres), to see if these men had any form of orthostatic hypotension.

We found that the prevalence of any form of orthostatic hypotension in these men was similar to what can be found in the general population. For example, only 5 patients met the criteria for the ‘classic’ definition of orthostatic hypotension. This means that, on its own, the use of an alpha-blocker is not enough to cause orthostatic hypotension. However, there was a much higher risk of orthostatic hypotension in men who used 10 or more medications, or those who had the most comorbidities. Thirteen of the 65 men fell in this group with much higher risk.

We conclude that for most older men, urologists or general practitioners (these are the doctors that mostly prescribe these drugs) do not need to be concerned with orthostatic hypotension as a side effect. However, they should think twice in patients with multimorbidity and patients who already use multiple other medications. For these patients, the benefits of starting alpha-blockers for urinary symptoms should be weighed against the increased risk of orthostatic hypotension.

Figure: an example of blood pressure tracking during standing up using the Finapres device. This patient had orthostatic hypotension.

Publication

Orthostatic blood pressure recovery in older males using alpha-blockers for lower urinary tract symptoms, an explorative study in a urology outpatient clinic Spies PE, Beune TNN, Heesakkers J, van Munster BC, Claassen JAHR. Orthostatic blood pressure recovery in older males using alpha-blockers for lower urinary tract symptoms, an explorative study in a urology outpatient clinic. J Clin Pharm Ther. 2022 Oct;47(10):1698-1703. doi: 10.1111/jcpt.13726.