Common blood pressure medicines do not put people at a higher risk of severe or fatal coronavirus symptoms, three major studies have found.
Doctors sounded the alarm in March about a possible link between the drugs – known as ACE inhibitors and angiotensin receptor blockers (ARBs) – and COVID-19.
ACE inhibitors include the likes of ramipril, lisinopril and other drugs ending in -pril; while ARBs include valsartan and losartan, and generally end in -sartan.
Studies in animals suggested the pills change the shape of cells in a way that makes it easier for the coronavirus to infect them and cause a more severe illness.
But the three new studies published in the prestigious New England Journal of Medicine (NEJM) have found the drugs have ‘no difference’ on the virus’ severity or the risk of someone contracting it.
Scientists said medicines taken by thousands of people could increase the risk of a coronavirus patient developing deadly symptoms (stock image)
Some people with high blood pressure or type 1 or type 2 diabetes have to take the drugs, which increase the amount of ACE2 that they have on their cells, in order to control their illness.
There had been concern arising from animal studies that these medicines might increase the body’s levels of a protein called ACE2, which the coronavirus latches on to when it invades human cells, thus increasing people’s vulnerability to the disease.
Confusing matters further, there were also contradictory animal studies that showed having more ACE2 proteins might lessen an inflammatory reaction in lungs to COVID-19, a beneficial effect.
There are more than 16million people with these diseases in the UK – but not all patients are given them so the exact number of people taking the drugs is unclear.
The most prescribed versions of the drugs in England are Ramipril, Losartan, Lisinopril and Candesartan, according to NHS data.
The common medications were prescribed almost 65million times in England last year and cost the NHS more than £100m.
They are given to treat diabetes or high blood pressure and around 10 per cent of people in the UK – some 6.6million – are estimated to take them regularly.
Each of the NEJM studies involved reviewing the records of thousands of people either on or not on the medicines and seeing if they got infected and how the disease progressed.
They then used statistical methods to control for other factors like underlying health conditions that might make people more susceptible to infection and to serious COVID-19.
Dr Harmony Reynolds, a cardiologist at New York University, who led one of the studies that involved about 12,600 people, said: ‘We saw no difference in the likelihood of a positive test with ACE inhibitors and with angiotensin receptor blockers.’
The studies were ‘observational,’ meaning the researchers observed the effect of a risk factor.
This type of investigation is always considered weaker than ‘experimental’ where an intervention is introduced along with a control, which leaves less to chance.
The authors of an accompanying editorial in the NEJM acknowledged the limitation, but added: ‘We find it reassuring that three studies in different populations and with different designs arrive at the consistent message.’
Dr Reynolds said the findings were relieving, because she had been getting questions from worried patients who had read press reports and were asking if they should stop their medicines.
‘I’m very happy to be able to tell patients that they should continue their blood pressure medications,’ she said.
This is especially important given that lockdown life itself appears to be causing high blood pressure, ‘maybe from stress or less exercise or eating differently,’ she added.
Mandeep Mehra, the medical director at Brigham and Women’s Hospital (BWH) Heart and Vascular Center who led another of the studies, said another fundamental question had been answered.
Mehra’s study, which looked at almost 9,000 patients across 11 countries, also tied the use of blood pressure medicines to a lower risk of death from COVID-19 – a finding not shared by the other two studies.
‘The same drugs that appear to have life saving benefits in patients with cardiovascular illness also appear to show us a signal of benefit in patients who are in the throes of COVID-19,’ he said.
He added it was unclear why this was the case – whether it was because the medicines were helping the heart which in turn made it more resilient to the effects of the virus, or whether they were doing something else.
‘What we can tell you is that, if you’re on a statin or an ACE inhibitor, by golly, please continue it,’ added Mehra.