There is no “magic bullet” to treat coronavirus and several drugs will probably be needed to tackle the virus, experts have said.
They said repurposing existing medicines is a faster alternative to developing and manufacturing new vaccines.
A team of researchers representing the International Union of Basic and Clinical Pharmacology caution that an effective and scalable vaccine is likely to take more than a year before it can be used to tackle the global pandemic.
Dr Steve Alexander from the University of Nottingham said: “While we’re waiting for a vaccine, drugs currently being used to treat other illnesses can be investigated as treatments for Covid-19 – in other words repurposed.
“There’s unlikely to be a single magic bullet – we will probably need several drugs in our armoury, some that will need to be used in combination with others.
“The important thing is that these drugs are cheap to produce and easy to manufacture. That way, we can ensure access to affordable drugs across the globe, not just for wealthier nations.”
The review, published in the British Journal of Pharmacology, looks at potential therapeutic drug targets – the chinks in the virus’s armour or weak spots in the body’s defences.
Two key targets appear to be proteins on the surface of our cells, to which Sars-CoV-2 binds allowing it entry – ACE2 and TMPRSS2.
TMPRSS2 appears to be common on cells, whereas ACE2 is usually present at low levels that increase depending on sex, age and smoking history.
Professor Anthony Davenport from the University of Cambridge said: “As we know these two proteins play a role in this coronavirus infection, we can focus on repurposing drugs that already have regulatory approval or are in the late stages of clinical trials.
“These treatments will have already been shown to be safe and so, if they can now be shown to be effective in Covid-19, they could be brought to clinical use relatively quickly.”
He added that any drug would need to focus on the three key stages of infection – preventing the virus entering human cells, stopping it replicating if it gets inside the cells, and reducing damage to tissue.
The team said existing drugs that are effective in clinical trials need to be rapidly identified so patients can be treated as soon as possible.
It said this needs to be done quickly also because cases are likely to fall during the summer, meaning there will be fewer people who can be recruited to clinical trials.
One existing drug being considered is remdesivir – originally developed for Ebola.
Clinical trials in America have suggested the drug may be beneficial for patients admitted to hospital with Covid-19, and the US Food and Drug Administration has approved it for emergency use.
The experts added that patience was needed in the wait for an effective vaccine.
Dr Alexander said: “Although there are a lot of vaccines being developed around the world, which we hope will be successful, it’s still going to take a long time before those vaccines are shown to be effective and can be manufactured at the scale needed to make an impact.”