SPIRONOLACTONE, commonly used in cases of heart failure, has surprised scientists by blocking infection by Epstein-Barr virus, in a breakthrough that could help people with a wide variety of herpes-related conditions. A new discovery could lead to an alternative treatment for the herpes virus. In 1996, Medical Microbiology reported that there were over 100 known herpes viruses, eight of which can normally affect humans. Herpes simplex virus type 1 (HSV-1) is transmitted by mouth and causes cold sores. HSV-2 is responsible for genital herpes, causing painful blisters or ulcers in the genital area. HSV-3, or herpes zoster, leads to chicken pox and potentially shingles. HSV-4, also called Epstein-Barr virus (EBV) is responsible for infectious mononucleosis, commonly known as glandular fever or “kissing disease,” because it spreads through saliva. EBV has also been linked to a number of other conditions, including cancers in humans. People who undergo a transplant, or whose immune system is already compromised, are especially at risk of EBV. According to the authors of the current study, EBV “infects the majority of humans worldwide.” The Centers for Disease Control and Prevention (CDC) call it “one of the most common human viruses in the world.” Most people, they say, will have this virus, but often there are no symptoms. Limited options for treatment of herpes There is only one class of antiviral medicine to treat herpes viruses, which means there is no alternative in cases of resistance. Scientists from the University of Utah School of Medicine, led by Dr. Sankar Swaminathan, have been searching for new drugs to treat viral infections. They were screening for drugs that might be effective against the herpes virus through a different mechanism than currently available therapies. The current drugs work by preventing a virus from replicating DNA, thus blocking a middle step of the viral infection cycle. Spironolactone (SPR), like existing drugs, was found to block a key step in viral infection that features in all herpes viruses, but a different step than the one targeted by current drugs. It prevented replication of the virus in cells by blocking the so-called SM protein, needed for a late step in the infection cycle. Based on these findings, the researchers see SPR as a good candidate for development into a new class of anti-herpes drug. Dr. Swaminathan, who is chief of infectious diseases at University of Utah Health Care and professor of internal medicine, comments: “It’s remarkable that a drug we have used safely in the clinic for over 50 years is also an effective EBV inhibitor.