Research has linked sodium-containing paracetamol with increased risks of cardiovascular disease (CVD) and all-cause mortality, even in people without hypertension.

The World Health Organization suggests that the total daily intake of sodium should not exceed 2.0g but the authors of a new observational study note that effervescent and soluble formulations of 0.5g paracetamol can contain 0.44g and 0.39g of sodium, respectively.

Taking the maximum paracetamol dose can mean ingesting 3.5g and 3.1g of sodium a day respectively.

Researchers used a database of GP records from the UK to identify 151,398 people with hypertension (mean age 73.4 years) and 147,299 people without hypertension (mean age 71.0 years).

In those with hypertension, sodium-containing paracetamol formulations increased the risk of CVD (heart attack, stroke and heart failure) by 59 per cent after allowing for confounders compared with non-users.

In people without hypertension, sodium-containing paracetamol formulations increased CVD risk by 45 per cent compared with non-users (one-year risks of 4.4 and 3.7 per cent respectively).

Mortality showed a similar pattern. In people diagnosed with hypertension, sodium-containing formulations were associated with a doubling in mortality compared with non-users (one-year risks of 7.6 and 6.1 per cent respectively). In people without hypertension all-cause mortality increased by 87 per cent compared with non-users.

Study leader Professor Chao Zeng, Xiangya Hospital, Central South University, Changsha, China, said that clinicians and patients should be aware of the risks and avoid unnecessary consumption of sodium-containing paracetamol, especially when taken for a long time. The risk of CVD and death rose as the duration of treatment with sodium-containing paracetamol formulations lengthened.

“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 cardio-vascular disease and death,” Professor Zeng said.

“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.”

(European Heart Journal doi:10.1093/eurheartj/ehac059)