A drug commonly used to manage HIV was successfully used to treat a man with coronavirus.

The Spanish newspaper El País reports that Miguel Ángel Benítez, 62, was successfully treated for coronavirus at a hospital in Seville with lopinavir/ritonavir (marketed as Kaletra), a protease inhibitor.

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“It’s an experimental usage of the drug that has given good results with other viruses,” said Albert Bosch, president of the Spanish Virology Society.

“One of the biggest advantages is that they are already approved for use, so there is little doubt about their safety.”

Protease inhibitors are antiviral drugs that bind to certain enzymes necessary to produce parts of the virus, inhibiting production of the virus in cells.

Kaletra was paired with interferon beta, a signaling protein that cells produce when they are infected and that increases resistance to viruses.

“The results we have so far for the use of these drugs to treat coronavirus give us hope,” said Santiago Moreno, head of infectious diseases at Ramón y Cajal Hospital in Madrid.

Of course, success in one case does not mean that the medications will work for everyone, and further testing and research is needed.