Data from both basic research and clinical experience continue to suggest that mesalamines and thiopurines are effective and efficient for the maintenance of remission ofinflammatory bowel diseases.Several decades following the formalization of their indications,attention on these two drugs has been fostered by recent achievements.Demonstration of the ability of mesalamine to activate a colonocyte differentiation factor has shed light on its chemopreventive effects on colorectal cancer;in addition to their anti-proliferative efficacy,thiopurines have been shown to be specific regulators of apoptosis.The two drugs are often coadministered in clinical practice.Recent advancements have shown that mesalamines exert a positive synergism in this context,insofar as they can inhibit sidemethylation of thiopurines and hasten the function of the main immunosuppressive pathways.Considering that up to 40% of patients cannot tolerate thiopurines,such renovated targets have stimulated efforts to improve compliance by research on the toxicity mechanisms.The definition of genetic polymorphisms in the enzymes of thiopurine metabolism,and the uncovering of synergistic drug interactions,such as that with allopurinol,are just two of the results of such efforts.Interaction between basic research and clinical practice has continued to inform indications and refine the prescriptions of mesalamines and thiopurines;these have not been restrained(they have been implemented in some cases)by the advent of the novel biological molecules with anti-cytokine activity. Data from both basic research and clinical experience continue to suggest that mesalamines and thiopurines are effective and efficient for the maintenance of remission of inflamatory bowel diseases.Several decades following the formalization of their indications, attention on these two drugs has been fostered by recent achievements. Demonstration of the ability of mesalamine to activate a colonocyte differentiation factor has shed light on its chemopreventive effects on colorectal cancer; in addition to their anti-proliferative efficacy, thiopurines have been shown to be specific regulators of apoptosis. two drugs are often coadministered in clinical practice.Recent advancements have shown that mesalamines exert a positive synergism in this context, insofar as they can inhibit sidemethylation of thiopurines and hasten the function of the main immunosuppressive pathways .Considering that up to 40% of patients can not tolerate thiopurines, such renovated targets have stimulated efforts to imp rove compliance by research on the toxicity mechanisms. the definition of genetic polymorphisms in the enzymes of thiopurine metabolism, and the uncovering of synergistic drug interactions, such as that with allopurinol, are just two of the results of such efforts.Interaction between basic research and clinical practice has continued to inform indications and refine the prescriptions of mesalamines and thiopurines; these have not been restrained (they have been implemented in some cases) by the advent of the novel biological molecules with anti-cytokine activity.