High sodium levels in drugs ‘putting patients at risk’.By James Meikle. theguardian.com. November 27, 2013. Call for clearer labelling on medicines after study finds pills with added sodium lead to greater chance of heart attack. Researchers have called on manufacturers provide clearer labelling of the salt content of medicines after they found that millions of people taking soluble aspirin, paracetemol, vitamin C and other drugs were at greater risk of heart attacks and strokes when there were high levels of sodium in the drugs.

Teams at Dundee University and University College London said taking the daily maximum doses of some medicines would exceed recommended daily limits of sodium, without any extra intake through their food. They said the public should be warned of the dangers of soluble and effervescent sodium-containing formulations and that these should be prescribed with caution by doctors, and only if the benefits outweighed the risks.
The study tracked more than 1.2 million patients over seven years and found that people who took sodium-containing versions of the drugs had a 16% increased risk of a heart attack, stroke or vascular-related death than those taking non-sodium versions. They were also seven times more likely to develop high blood pressure and 28% more likely to die prematurely than those taking similar drugs with no salt.
The drugs in the British Medical Journal study included effervescent, dispersible and soluble preparations. The drugs included paracetamol, aspirin, ibuprofen, vitamin C, calcium, zinc and metoclopramide, which is used for migraines.
While many commonly prescribed medicines have sodium added to improve their absorption into the body, the effect has largely been unknown. It is well established that aspirin can lower the risk of heart disease or a stroke through a blood clot, but it is recommended for use only in people who have already suffered a cardiovascular event, not as a preventative measure.
Jacob George, a senior clinical lecturer and honorary consultant in clinical pharmacology at Dundee University, who led the research, said: "These drugs are also available over the counter, they can be picked up in the supermarket. We have no control over how many millions of people are buying these drugs.
"The ones we looked at were prescribed by GPs, but there’s a potentially much larger problem with these drugs being bought over the counter and in supermarkets."
George said that because of the lack of labelling of sodium content, researchers had struggled to get information and often had to call manufacturers many times.
It is well known that high salt intakes are linked to higher risk of a heart attack or stroke. Mike Knapton, of the British Heart Foundation, said: "It is important to remember that this research applies to people who are taking these medicines regularly. This does not mean that occasional use could damage your heart health. To give us an idea of whether these risks translate for medicines bought over the counter, we would need to see further research focusing on non-prescription medicine."
Though the study was an important reminder for doctors and patients to carefully weigh up the risks and benefits of soluble or effervescent medicines, said Knapton, "it’s important not to simply stop taking your dose. Make an appointment with your doctor to discuss any concerns."
Journal reference: Jacob George, Waseem Majeed, Isla S Mackenzie, Thomas M MacDonald, Li Wei. “Association between cardiovascular events and sodium-containing effervescent, dispersible, and soluble drugs: nested case-control study”.  BMJ 2013;347:f6954. doi: http://dx.doi.org/10.1136/bmj.f6954