CHICAGO – The risk of cardiovascular and hypotension-related events is higher with alpha-blockers than with other hypertension drugs, but almost 20 years after the pivotal ALLHAT trial first raised safety concerns, they are still widely used, according to investigators from the University of Ottawa.
ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) linked the alpha-blocker doxazosin (Cardura) to an increased risk of heart failure and stroke, which led to the early cessation of the doxazosin arm. Guidelines no longer include alpha-blockers among the primary options for hypertension (JAMA. 2000;283[15]:1967-75).
However, there’s been some doubt about ALLHAT; doxazosin patients had diuretics withdrawn as part of the study, which might have contributed to the increased risks. “A lot of arguments have been made that perhaps alpha-blockers aren’t that bad and maybe should still be used, so we took a second look,” said lead investigator and nephrologist Swapnil Hiremath, MD, an assistant professor of medicine at the University of Ottawa.
What he and his team found “confirmed and expanded on the findings of ALLHAT.” Apart from a few specific situations, “don’t prescribe alpha-blockers. If a patient is on an alpha-blocker, consider prescribing an alternative,” Dr. Hiremath said at the joint scientific sessions of the American Heart Association Council on Hypertension, AHA Council on Kidney in Cardiovascular Disease, and American Society of Hypertension.
The drugs are still widely used, according to the team’s review of Ontario health data. From 1995 to 2015, nearly 81,000 patients were prescribed alpha-blockers for hypertension, sometimes as monotherapy, with no real downward trend in prescriptions over time.
There are some selected indications for alpha-blockers, including intolerance of other antihypertensives, pheochromocytoma management, and resistant hypertension. “So I thought maybe there would be 5,000 or 10,000. The fact that we found almost 81,000 was an eye-opener. I’m pretty sure 81,000 patients in Ontario don’t have resistant hypertension,” Dr. Hiremath said.
Patients with benign prostatic hypertrophy, another indication, were excluded from the study.