Introduction
We wish to draw attention to the possibility of repurposing the existing calcium channel blocking drug tetrandrine for the treatment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.
Tetrandrine is a bisbenzylisoquinoline that can be extracted from the perennial vine plant Stephania tetrandra S. Moore (Chinese patent WO2004009106A1, 2002), which has been used in traditional Chinese medicine ([1], [2] and references therein). It can also be synthesised chemically (US Patent 10,023,584 B2, 2018, [3]) .
There is extensive literature on the anti-inflammatory, immunosuppressive, oncological and cardiovascular effects of tetrandrine [2;4-6]. It is licensed in China for the treatment of silicosis, but to our knowledge has not been licensed for viral illnesses in any country to date.