Sofosbuvir, a hepatitis C treatment drug, can adversely interact with tenofovir disoproxil, a HIV treatment drug, according to research led by Bingfang Yan, PhD, professor of biomedical and pharmaceutical sciences at Kingston-based University of Rhode Island's College of Pharmacy/Academic Health Collaborative.
Hepatitis C drugs that contain sofosbuvir, such as Sovaldi and Harvoni, are often used in combination with other medications to combat co-infections with different viruses, such as HIV and hepatitis B.
The new study, published in the Journal of Hepatology, found that sofosbuvir inhibits tenofovir disoproxil's ability to decompose in water, affecting the CES-2 enzyme's ability to activate tenofovir disoproxil. This has "implications of increased kidney toxicity," Dr. Yan said in a statement.
"The enzyme normally breaks down through hydrolysis, activating such medicines as tenofovir disoproxil or inactivating such medicines as aspirin," he also said.
Dr. Yan suggests prescribing the drugs with instructions to take them at different times or via different methods, for example, the HIV drug can be administered via the skin while the hepatitis C drug can be taken orally.