Many people rely on painkillers for various ailments and injuries. Common problems such as headaches, back aches and temperatures can be eased by taking pills like paracetamol and ibuprofen.
While these are safe to use in accordance with the package instructions, research has shown there are risks to taking them regularly.
It had been previously assumed that paracetamol was a completely safe drug to use in patients with high blood pressure until fairly recently.
However, a 2022 study found that long-term use of paracetamol could increase the risk of heart disease and stroke among people with hypertension.
The effect on blood pressure is similar to that of non-steroidal anti-inflammatories (NSAIDs), such as ibuprofen, researchers have said.
As part of the study conducted by a team at the University of Edinburgh, 110 patients with a history of high blood pressure were prescribed either one gram of paracetamol four times a day or a matched placebo for two weeks.
Four grams of paracetamol a day is a routinely prescribed dose in patients with chronic pain.
All patients received both treatments, with the order randomised and blinded.
Those prescribed paracetamol saw a significant increase in their blood pressure, compared with those taking the placebo.
This rise was similar to that seen with non-steroidal anti-inflammatory drugs, and might be expected to increase the risk of heart disease or stroke by around 20 percent.
Therefore, the team said patients who have a long-term prescription for the painkiller should be given the lowest effective dose for the shortest time possible.
Professor James Dear, personal chairman of clinical pharmacology at the University of Edinburgh, explained: “This study clearly shows that paracetamol, the world’s most used drug, increases blood pressure, one of the most important risk factors for heart attacks and strokes.”
Prof Dear said doctors and patients should “together consider the risks versus the benefits”, especially where patients are at risk of cardiovascular disease.
He continued: “In summary, we’ve shown that two weeks of treatment with paracetamol increases blood pressure in patients who have hypertension (high blood pressure).”
But lead investigator Dr Iain MacIntyre, consultant in clinical pharmacology and nephrology at NHS Lothian said people who use paracetamol every once in a while shouldn’t worry.
In a university release he said: “This is not about short-term use of paracetamol for headaches or fever, which is, of course, fine – but it does indicate a newly discovered risk for people who take it regularly over the longer term, usually for chronic pain.”
The study found that after people stopped taking the drug, their blood pressure returned to what it was at the start of the study, suggesting the drug increased it.
According to the experts, the study was set up to see a very small effect on blood pressure, and they were surprised to see a much bigger impact.
Professor Sir Nilesh Samani, medical director at the British Heart Foundation, which funded the study, said the findings “emphasise why doctors and patients should regularly review whether there is an ongoing need to take any medication” and “always weigh up the benefits and risks.”
Around one in three adults in the UK is thought to have high blood pressure. In England this is 31 percent of men and 26 percent of women.
If you are concerned about your blood pressure and any drugs you take regularly you should speak to your GP.