LONDON — Researchers at the University of Dundee and University College London on Wednesday found that taking the maximum daily dose of some medicines would exceed the recommended daily limits for sodium, without any additional dietary intake and potentially become an added risk factor for heart disease.
They say the public "should be warned about the potential dangers of high sodium intake from prescribed medicines" and that sodium-containing formulations "should be prescribed with caution only if the perceived benefits outweigh the risks."
According to the researchers, many commonly prescribed medicines have sodium added to improve their absorption into the body.
They also call for the sodium content of medicines to be clearly labelled in the same way as foods are labelled.
Overall, the researchers found that patients taking the sodium-containing effervescent, dispersible and soluble medications had a 16% increased risk of a heart attack, stroke or vascular death compared with other patients taking the non-sodium versions of those exact medications, the researchers noted. Patients taking the sodium-containing drugs also were seven times more likely to develop high blood pressure, and overall death rates also were 28% higher in this group.
The team, led by Jacob George, senior clinical lecturer and honorary consultant in clinical pharmacology at the University of Dundee, compared the risk of cardiovascular events (non-fatal heart attack, non-fatal stoke, or vascular death) in patients taking sodium-containing effervescent, dispersible and soluble medications with those taking non-sodium versions of the same drugs between 1987 and 2010.
More than 1.2 million U.K. patients were tracked for an average of just over seven years. During this time, more than 61,000 incident cardiovascular events occurred.
Factors likely to affect the results — such as body mass index, smoking, alcohol intake, history of various chronic illnesses and use of certain other medications —were taken into account, the researchers reported.
The authors acknowledged that there is still some controversy regarding the relation between dietary sodium and cardiovascular events, but say their findings "are potentially of public health importance."