THURSDAY, Oct. 17, 2019 -- A common type of blood pressure
medication might be associated with an increased risk of suicide, a new study
suggests.
People taking angiotensin receptor blockers (ARBs) appear to be
more likely to die by suicide, compared to those who take another type of blood
pressure drug called ACE inhibitors, researchers found.
Patients using ARBs had a 63% increased risk of death by suicide
over people on ACE inhibitors, the findings showed. But the study could not
prove a cause-and-effect relationship.
"There is reason for some concern," said lead researcher
Muhammad Mamdani, director of the Applied Health Research Center of the Li Ka
Shing Knowledge Institute at St. Michael's Hospital, in Toronto. "Now
would I be going en masse and change everybody's prescriptions? No, not just
yet. We should have more work done in this area."
"But certainly if I had a choice as a patient, I would be
choosing the ACE inhibitor over the ARB," Mamdani concluded.
ARBs and ACE inhibitors both work by interfering with the action
of angiotensin II, a hormone in the body that causes blood vessels to
constrict.
ARBs work by blocking the ability of angiotensin II to bind with
receptors and command blood vessels to narrow, while ACE inhibitors actually
lower the amount of the hormone produced within the body.
Both drugs are widely used to treat high blood pressure, chronic
kidney disease, heart failure and diabetes, the study authors said in
background notes.
Mamdani and his colleagues pursued their new research based on
earlier studies suggesting ARBs might be linked to suicide risk.
Using Canadian health databases, the investigators identified 964
people who died by suicide within 100 days of being prescribed either an ARB or
an ACE inhibitor. They then compared those people to a control group of just
over 3,000 people also taking either type of blood pressure medication.
The results showed that people taking ARBs had a statistically
significant higher risk of suicide than those on an ACE inhibitor.
"It is a fairly commonly used set of drugs, and lots of
people would be affected by it. Certain people, especially if you're
susceptible to mood disorders, may be even more at risk," Mamdani said.
He noted that ARBs might cause levels of angiotensin II to
increase in the brain.
"That could be related to mood disorders, and that could
trigger suicidal-type behavior," Mamdani suggested.
However, there's currently no evidence that angiotensin II has
anything to do with moods or suicidal intent, said Dr. Robert Carey, dean
emeritus of the University of Virginia School of Medicine.
"I think those speculations are exactly that," Carey
said. "There is no realistic mechanism to which one could attribute that
difference in suicide risk."
Carey noted that other factors that could influence suicide risk
might have come into play with these patients. For example, some were taking
antidepressants or benzodiazepines, "which might have had an influence on
the suicide rate," he said.
The study also didn't assess underlying substance abuse, prior
mental health hospitalizations, or previous emergency department visits, said
Dr. Suzanne Steinbaum, a cardiologist with the Mount Sinai Hospital in New York
City.