Washington: A class of drugs that is commonly used to treat patients with hypertension, and heart disease does not increase the risk of developing severe COVID-19 as previously feared, according to a study in mice.Scientists, including those from Northwestern University in the US, said there have been widespread concerns that the drugs -- ACE inhibitors and angiotensin receptor blockers (ARB) -- might cause an increase in the human cell surface receptor protein ACE2 which the novel coronavirus uses to enter and infect cells.Earlier studies had cautioned that this class of drugs could possibly increase the risk for the novel coronavirus, SARS-CoV-2, infection and elevate COVID-19 severity.However, the new findings, published in the Journal.