But there is no evidence they raise the risk of contracting the virus.
About one in every three Australians has high blood pressure and many of them will be using those drugs.
Angiotensin receptor blockers sold in Australia include valsartan, irbesartan, candesartan, losartan, telmisartan, and olmesartan. ACE inhibitors are sold under the names captopril, enalapril, fosinopril, perindopril, ramipril and quinapril.
Patients and GPs are now contacting health authorities asking if they should discontinue use of the medicine, The Age and The Sydney Morning Herald have learnt.
That has led at least 12 medical colleges and societies around the world, including the International Society of Hypertension, to issue statements strongly advising patients to continue to take the drugs.
“We don’t have any clinical evidence angiotensin receptor blockers and ACE inhibitors affect your susceptibility to COVID-19. We don’t have any evidence of that,” said Professor Louise Burrell, head of the cardiovascular research group at the University of Melbourne.
Professor Burrell has spent 15 years researching the drugs and up until 2018 was on the council for the International Society of Hypertension.
“The consequences of stopping taking angiotensin receptor blockers or ACE inhibitors is your blood pressure becomes out of control,” she said.
“That’s associated with increased mortality from heart attacks and strokes.
“We don’t recommend our patients to stop taking these drugs, unless advised to do so by their physician.”
The issue is a microcosm of the difficult challenge COVID-19 is posing for scientists and doctors.
New studies are being widely spread around – often on social media – before they have been peer-reviewed by other experts.
In the case of ACE inhibitors and ARBs, the issue seems to have sprung from two letters to the editor of the BMJ and the Lancet authored by doctors in Switzerland.
They pointed out that SARS-CoV-2, the virus that causes COVID-19, appears to gain entry to the cell by attaching to ACE2 receptors on the cell’s surface.
In animal studies – which usually do not translate to humans – two classes of heart medication, ACE inhibitors and ARBs, have been shown to increase the number of ACE2 receptors in the heart.
Because of that, the doctors suggested the drugs may be increasing the risk of a person contracting the virus.
But a letter to the editor is a long way from a high quality peer-reviewed study.
“People are saying these drugs make your ACE2 levels go up, and that could be bad because that could make it easier for the virus to get in. But we don’t have any evidence of that,” says Professor Burrell.
At this stage, there is no clinical data suggesting the drugs are harmful for people infected with COVID-19.
“This speculation,” the European Society of Cardiology said in its statement, “does not have a sound scientific basis or evidence to support it”.
Updated health advice for Australians
The symptoms of coronavirus include:
- Shortness of breath; and
- Breathing difficulties
If you suspect you or a family member has coronavirus you should call (not visit) your GP or ring the national Coronavirus Health Information Hotline on 1800 020 080.
Liam is The Age and Sydney Morning Herald’s science reporter