(Adds reporter’s name at bottom)
Oct 18 (Reuters) – People using a common class of
antidepressants may have slightly increased odds of suffering
bleeding in the brain – though the risk is still very small,
according to a Canadian study looking at more than 500,000
people.
The antidepressants are known as selective serotonin
reuptake inhibitors (SSRIs) and include widely used drugs like
fluoxetine (Prozac), sertraline (Zoloft), citalopram (Celexa)
and paroxetine (Paxil.)
The SSRIs have been linked to a risk of stomach bleeding,
but studies have come to conflicting findings on whether SSRI
users have any higher risk of hemorrhagic strokes, which happen
when there is bleeding in or around the brain.
For the study, which appeared in the journal Neurology,
researchers pooled the findings from 16 past studies involving
more than 500,000 people who were on SSRIs or not.
Overall, antidepressant users were about 40 to 50 percent
more likely to suffer bleeding in or around the brain.
But while those numbers might sound big, the risks to any
one person would be “extremely low,” said lead researcher Daniel
Hackam, an associate professor of medicine at Western University
in London, Ontario, Canada.
Based on these figures, he said, there would be one brain
hemorrhage for every 10,000 people using an SSRI over one year.
What’s more, the findings do not prove that the
antidepressants directly cause brain bleeds. It’s possible,
Hackham said, that SSRI users are “sicker” than non-users or
have habits that put them at greater stroke risk.
The researchers tried to account for those factors in their
calculations, but some of the studies they analyzed lacked key
information, such as peoples’s smoking and drinking habits, and
whether they had diabetes.
“We can’t infer cause and effect from this,” Hackam said.
On the other hand, there are reasons to believe it’s the
medications themselves. For one, the hemorrhage risk seemed
greatest in the first months after people started using an SSRI.
There’s also a biological argument. SSRIs seem to make it
harder for blood cells called platelets to clump together and
form clots – and there can be a big drop in a person’s platelet
functions in the first weeks after starting an SSRI, he said.
Still, he stressed that people on the antidepressants should
not be alarmed.
“I think that overall, these medications are quite safe,” he
added.
But people who are already at increased risk of a brain
hemorrhage may need to be careful. That includes people who have
had a brain bleed in the past, or are on medications that reduce
blood clotting.
SOURCE: http://bit.ly/Q5TNI
(Reporting from New York by Amy Norton at Reuters Health;
editing by Elaine Lies)
