Enteric-coated mycophenolate sodium: tolerability profile compared with mycophenolate mofetil

Mycophenolate mofetil is one of the most frequently used immunosuppressive drugs in solid organ transplantation. Although the adverse effect profile of mycophenolate mofetil is comparatively benign, gastrointestinal adverse effects are a major concern. The adverse effects may require a dose reduction or discontinuation, thus limiting its clinical efficacy. Enteric-coated (EC) mycophenolate sodium is a new formulation of mycophenolic acid (MPA) that delivers the active moiety MPA, the same active moiety delivered by mycophenolate mofetil. It has been developed to help protect the upper gastrointestinal tract. It is implied that a reduction of adverse drug effects as well as a reduction of dose may improve efficacy and compliance. Noncompliance is often underestimated in solid organ transplant recipients, and adverse drug effects increase medication nonadherence. Recent clinical trials comparing EC mycophenolate sodium and mycophenolate mofetil in kidney recipients reported similar rates of efficacy and adverse effects. It is noteworthy that systemic MPA exposure is higher with EC mycophenolate sodium than with mycophenolate mofetil, without increased gastrointestinal toxicity. This finding is quite surprising, because part of MPA-associated gastrointestinal toxicity is related to its antiproliferative effect on enterocytes. However, enteric coating of MPA did not markedly reduce the number of gastrointestinal adverse effects. Further studies focusing on dosage, therapeutic drug monitoring and immunosuppressive regimens may reveal benefits of EC mycophenolate sodium for optimal individualised immunosuppression and improved compliance. At present, EC mycophenolate sodium is an alternative immunosuppressant to mycophenolate mofetil in kidney transplant recipients with an almost identical efficacy and safety profile.