Millions of patients worldwide taking
effervescent, dispersible and soluble medicines have an increased risk of heart
attacks and strokes because of the high salt content of such drugs, scientists
said on Wednesday.
Researchers from Britain's University of
Dundee and University College London found that with some "fizzy"
versions of painkillers, vitamin supplements or other common medicines, taking
the maximum daily dose would on its own exceed daily recommended limits for
sodium, the main component of salt.
High salt intake has been linked to high
blood pressure, or hypertension, which is a key risk factor for strokes, heart
attacks and other cardiovascular diseases.
In a study published in the British Medical
Journal (BMJ), researchers found that patients taking dispersible forms of
drugs had a 16% increased risk of a heart attack, stroke or vascular death
compared with patients taking the non-high-sodium versions of the same
Jacob George, an honorary consultant in
clinical pharmacology at Dundee who led the study, said patients, and consumers
of over-the-counter medicines – such as soluble aspirin, effervescent vitamin
C, or Bayer's Alka Seltzer for example – "should be warned about the
potential dangers" of high sodium intake in medicines.
should be aware
Doctors, he added, should be aware of the
potential dangers and prescribe fizzy or soluble forms of drugs "with
caution, only if the perceived benefits outweigh the risks. There
are a lot of patients who need to use these formulations – those who have
difficulty swallowing large tablets, for example," George told Reuters in
a telephone interview.
"But what we want is for patients to
be able to make an informed decision with the help of their
doctor." Although there is some debate on the issue, many health experts
believe that eating too much salt is bad for health and numerous studies have
linked excess salt intake to high blood pressure, which can lead to strokes and
The World Health Organisation recommends a
daily upper limit of less than 2 grams of sodium – about the amount in one
teaspoon of salt.
For this latest study, George's team
tracked more than 1.2 million patients, comparing those taking
sodium-containing effervescent, dispersible and soluble medicines with those
taking non-sodium versions of the same drugs.
The study ran between 1987 and 2010 and
patients were tracked for an average of just over seven years.
During this time, over 61 000 new so-called
cardiovascular events – including heart attacks and strokes – occurred in the
patients being studied.
Factors likely to affect the results, such
as body mass index, smoking, alcohol intake, history of various chronic
illnesses and use of other medicines, were taken into account.
Beside the 16% higher risk of a heart
problem or stroke, the team also found patients taking sodium-containing drugs
were seven times more likely to develop high blood pressure, and their overall
death rate was 28% higher.
The researchers acknowledged that there is
still some controversy about the link between dietary sodium and heart risks,
but say their findings were anyway "potentially of public health