Sometimes – not very often, mind you – medicine catches a break.

Researchers from the Universities of Leeds, Nottingham and Glasgow in the UK have discovered that a group of drugs already in everyday use to treat psychosis or depression may also be used to defeat deadly and emerging viruses.

The rather scary new viruses the team was focused upon included lethal human pathogens such as Hantaviruses and Crimean-Congo hemorrhagic fever virus. The latter is a widespread disease that is becoming more prevalent in Mediterranean countries and endemic in Africa, the Middle East and some Asian countries, where outbreaks can kill up to 40 percent of the people who contract it.

The common drugs used in the research included the anti-psychotic haloperidol, the anti-depressant fluoxetine, and a local anesthetic, bupivacaine. What the scientists discovered is that these drugs block the ion channels that regulate potassium levels in those cells. Ion channels normally control the balance of chemicals such as potassium, calcium and sodium within our cells.

Finding ways to stop viruses from spreading is always good news, of course, but there's the hidden reason why doctors are thrilled when we can address the problem with “old school” drugs and not something new and fresh out of the beaker. Dr. John Barr, who helped develop the idea at Leeds, explained: "Very few new antiviral drugs have made it into clinical use in the last 15 years. One of the main reasons is cost; these are very expensive drugs to develop.

"Taking a drug that has already been proven to be safe, and using it to target a different condition or infection - a process known as drug re-purposing - bypasses this expensive and time-consuming stage.”

Dr Alain Kohl, who headed up the research at the University of Glasgow, said: "If existing drugs are confirmed to be effective against known members of a particular virus family, this opens up the possibility of using these 'off-the-shelf' treatments in a rapid response against dangerous new related virus strains that emerge."