Conclusion
The world has faced a new pandemic that has no proven pharmacotherapy despite all the attempts to develop a new effective medicine or vaccine with an acceptable safety profile. The current review has provided a collective data on the potential beneficial properties of methylxanthines like pentoxifylline and caffeine as an adjuvant therapy to treat COVID-19 patients. Addressing the broad spectrum of COVID-19 symptoms including respiratory failure due to hypersensitivity and exaggerated immune response, is challenging. Pentoxifylline and caffeine with extensively proven therapeutic properties like anti-inflammatory, antioxidant, immunomodulatory, antiviral, as well as their beneficial effects in the alleviation of respiratory symptoms can be considered as an adjuvant treatment in COVID-19 patients. Moreover, pentoxifylline can also address the treatment of thrombotic complications, a recently identified manifestation of COVID-19. Although direct evidence of pentoxifylline and caffeine in COVID-19 patients are yet to be studied and also possible side effects should be considered, the insights gained from this review highlighted their efficacy and safety in COVID-19 and can be used to develop additional strategies to tackle this global challenge.