Paracetamol has been linked to an increased risk of heart disease and death due to “hidden” salt in some types, a new study has found.

As more people take care of what they eat, many may be unaware of the levels of salt in some medicines that they take.

Researchers set out to compare outcomes for people who take sodium-containing soluble, or an effervescent, paracetamol and those who take the pain relief drug with no salt in it.

The team used data from 790 UK GP surgeries which collectively look after 17 million patients.

They tracked 60 to 90-year-olds between 2000 and 2017 who had either been prescribed salt containing paracetamol or non-salt-containing paracetamol – those in tablet, capsules or oral suspension forms.

The international team of researchers tracked 300,000 people, half had high blood pressure and half did not, for a year.

The study, published in the European Heart Journal, found that the risk of cardiovascular disease was higher among those who took paracetamol with salt in it.

The researchers found the risk of heart attack, stroke or heart failure after one year for patients with high blood pressure taking sodium-containing paracetamol was 5.6%, while it was 4.6% among those taking non-sodium-containing paracetamol.

Among those who did not have high blood pressure, the risk of cardiovascular disease after a year was 4.4% among those taking salt-containing paracetamol compared to 3.7% for those taking paracetamol without salt.

Risk of death during the follow-up period was also higher among those taking paracetamol with salt in it.

Why is salt included in paracetomal?

Salt is used in some soluble paracetamol because it can encourage the process of the breakdown of the tablet in water.

Experts have said that some people can exceed their recommended daily salt limit through a full course of salt-containing paracetamol alone.

Others called for front of pack warnings for paracetamol which contains high levels of salt.

Medics also said that people should be prescribed drug formulations with an extremely low amount of salt or none at all.

Lead author of the study, Professor Chao Zeng from Central South University in Changsha, China, said: “Given that the pain relief effect of non-sodium-containing paracetamol is similar to that of sodium-containing paracetamol, clinicians may prescribe non-sodium-containing paracetamol to their patients to minimise the risk of cardiovascular disease and death.

“People should pay attention not only to salt intake in their food but also not overlook hidden salt intake from the medication in their cabinet.”