Leprosy reactions: clinical Pharmacologist perspective with repurposed medications

The elimination of leprosy has been possible with the available anti-leprotic drugs. However, the lepra reactions usually occur months or years after multi-drug therapy completion, and continue to be a formidable challenge mainly owing to its role in causing nerve damage and disability. Corticosteroids are commonly used but they lead to systemic complications, and hence require dose reduction and adjunct therapy with a different target. Various drugs with different targets have been identified and are in practice to treat lepra reactions. The newer targets can include genetic and tissue targets in the skin and nerve. Thalidomide treatment reducing pentraxin-3, toll-like receptor antagonists, minocycline, apremilast, immunomodulators, and tenidap can be helpful in lepra reaction. Other modalities to manage lepra reactions include plasma exchange, intravenous immunoglobulins, and immunotherapy. Most of these treatments are based only on the pathological process of the reaction and tend to be incomplete leading to recurrence. Newer multimodal approaches are required based on various biomarkers (genetic, tissue, serological), which can be monitored to prevent the recurrence of reactions. Hence, there is a need for newer targets and drugs to be identified for the management of lepra reactions.