Stroke and heart risk of paracetamol
‘Drug raises chance of disease by fifth’
REGULAR use of paracetamol may increase risk of heart disease and strokes in people with high blood pressure, experts have warned.
The painkiller has long been considered a safer alternative in the long term to non-steroidal antiinflammatory drugs (NSAIDs) such as ibuprofen, which are known to increase blood pressure.
But a study has now found paracetamol can raise blood pressure by a similar amount to NSAIDs after just four days of use.
Researchers said the effect could increase risk of heart disease or stroke by around a fifth.
The findings suggest doctors should consider using smaller doses or stopping usage if the drug is not offering much benefit, they said.
Professor David Webb, chair of therapeutics and clinical pharmacology at the University of Edinburgh, said: “It’s definitely worth seeing if you could reduce the dose if you’ve been established on paracetamol and if your blood pressure is high.
“But I think there will always be a role for paracetamol and it will be a trade-off between getting the blood pressure right and the chronic pain right for those patients.”
Prescribed
In a trial, 110 patients with a history of high blood pressure, or hypertension – who are already at increased risk of heart disease and strokes – received one gram of paracetamol four times a day during one period, and a placebo dose during another.
The study found the drug increased daytime systolic blood pressure by an average of 4.7mmHG compared to placebo.
The effects began after four days and lasted for the two weeks patients took it. Blood pressure returned to normal soon after they stopped.
The findings are particularly important for patients with chronic pain, who may be prescribed painkillers over a long period of time.
Around a third of Britons have high blood pressure and around one in 10 people are thought to be receiving prescribed paracetamol.
Prof Webb recommended doctors start patients on low doses and increase the dose to no higher than needed to manage their pain.
Those starting treatment should be closely monitored so doctors can lower a dose or stop it altogether if it has an adverse effect.
Prof Webb added: “Actually having this knowledge is really helpful because it means we can keep a closer eye on it, we can discuss it with our patients, we can protect them better.”
Experts stressed that the findings, published in the journal Circulation, did not apply to people taking paracetamol for a short period of time, such as to treat a headache.
As the study only involved people with a history of hypertension, it did not show whether the painkiller also raises blood pressure in healthy people.
But a previous study of 80,000 nurses in the US suggested it could double the risk of someone developing hypertension.
Dr Richard Francis, head of research at the Stroke Association, said: “High blood pressure is the single biggest risk factor for stroke. This new and robust study adds to previous research and suggests regular paracetamol causes blood pressure to quickly increase in people who are already at risk of stroke and heart attacks.
“It’s therefore important that doctors regularly reflect on the risks and benefits of paracetamol.”
Findings…Prof Webb
Professor Sir Nilesh Samani, medical director at the British Heart Foundation, which funded the study, said: “The research highlights why doctors and patients should regularly review whether there is an ongoing need to take any medication, even something that may seem relatively harmless like paracetamol, and always weigh up the benefits and risks.”