Use of minocycline in viral infections.

Repurposing of old drugs is a useful concept as it helps to minimize costs associated with the research and development of a new drug. Minocycline, a common second generation antibiotic, has been shown to possess several other beneficial effects other than its intended uses. The antiviral role of minocycline has generated considerable interest from the last decade. It was first shown to be beneficial in preventing human immunodeficiency virus (HIV) infections and later it was reported to improve cognitive deficiencies associate with neuroAIDS. However, its antiviral efficacies are not limited to retroviruses alone. In animal models or in vitro systems of flaviviral infections (especially Japanese encephalitis virus), minocycline has been shown to be highly effective. However, not all effects are based on direct inhibition of viral replication. The general anti-inflammatory and immunomodulatory properties of minocycline are also responsible in part, in imparting the protective effects. Owing to the fact that minocycline is well tolerated by most people and that the drug has nearly 40 years history of usage, it is an exciting prospect to try out in other viral infections.