Many people are left with Long Covid after a coronavirus infection – with breathlessness, muscle pain, memory problems and, above all, chronic exhaustion that worsens with exertion. There is still no cure. Now a large clinical trial from the United Kingdom offers cautious grounds for hope.
A team led by Amitava Banerjee of University College London tested whether common medicines already approved for other conditions could ease the fatigue. Nearly 800 patients took part across twelve clinics in England and Scotland, all of them suffering severe exhaustion for more than a year. Over twelve weeks they received – singly or in combination – the antihistamine loratadine, the blood thinner rivaroxaban or the anti-inflammatory gout drug colchicine; a control group received none of them.
After twelve weeks, fatigue had eased slightly in every group – by 4.3 of 40 points, including the control group. "The effect is larger than you would expect from the passage of time alone," says co-author Melissa Heightman, who attributes it to focused medical care.
One combination worked best
The decisive finding was a combination: patients who took the antihistamine together with colchicine reduced their fatigue by a further 1.5 points. Both drugs act on the immune system – they may improve the immune response disrupted by Long Covid, Banerjee says, though the mechanism remains unclear. The benefit did not last beyond the end of treatment: "These agents alone are not enough to improve symptoms in the long term."
Even so, the researchers see the result as an important step. "The fact that these safe, cheap medicines, already used for other diseases, show at least a slight effect is incredibly important," says Danny McAuley of the National Institute for Health and Care Research. Even small effects, adds co-author Emma Wall of Queen Mary University of London, point to the biological processes behind Long Covid – and thus to targets for more effective therapies.
A negative result was revealing too: the blood thinner rivaroxaban brought no improvement beyond general care – even though clotting disorders are considered a possible cause of Long Covid. "Our results provide no argument for taking anticoagulants against Long Covid," Banerjee says. The study appeared in the journal The Lancet Infectious Diseases.