What is the dosage of Mycophenolate Mofetil (MMF) 500mg twice a day?

From the Guidelines

MMF 500 mg BID is an appropriate initial dosage for adult patients with idiopathic inflammatory myopathies (IIM), which can be increased up to 2 g/d (1000 mg twice daily) based on drug tolerability and therapeutic response. This dosage is supported by a study published in the Mayo Clinic Proceedings 1, which suggests initiating MMF at a dosage of 500 mg twice daily and increasing the dosage by 500 mg every week, sometimes every 2 weeks, up to a goal dosage of 2 g/d. The study also highlights the importance of monitoring for adverse effects, such as nausea and loose stools, and laboratory evaluation to monitor for leukopenia or transaminitis.

Key Considerations

• MMF is an immunosuppressive medication that works by inhibiting inosine monophosphate dehydrogenase, an enzyme crucial for purine synthesis in lymphocytes, thereby suppressing T and B cell proliferation and antibody formation.
• The total daily dose of 1000 mg is considered moderate, with dosing typically ranging from 1000-3000 mg daily depending on the condition being treated and patient factors.
• Common side effects include gastrointestinal disturbances (nausea, diarrhea), increased risk of infections, and potential blood count abnormalities.
• Regular blood monitoring is essential while on this medication, and women of childbearing potential should be counseled to use 2 reliable forms of birth control because MMF is also teratogenic.

Comparison with Other Guidelines

A guideline published in Kidney International 1 suggests the use of MMF 500–1000 mg twice daily for 1–2 years for patients who are intolerant of corticosteroids, CYC, and CNIs. However, this guideline is not directly applicable to the treatment of IIM, and the study published in the Mayo Clinic Proceedings 1 provides more specific guidance on the use of MMF in this context.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION Renal Transplantation Adults A dose of 1 g administered orally twice a day (daily dose of 2 g) is recommended for use in renal transplant patients. The recommended dose for renal transplant patients is 1 g twice a day, which is higher than the given dose of MMF 500 mg BID.

• The given dose is lower than the recommended dose for renal transplant patients. 2

From the Research

MMF 500 mg BID Dosage

• The dosage of MMF 500 mg BID has been studied in various clinical trials, with a focus on its efficacy and safety in preventing organ rejection in transplant patients 3, 4, 5, 6, 7.
• A study published in 2021 found that a risk-stratified approach to MMF dosing, with patients receiving either 500 mg twice daily or 1000 mg twice daily, resulted in similar rates of biopsy-proven rejection, graft loss, or mortality at 1-year post-transplantation 3.
• Another study published in 2010 assessed the bioequivalence of a generic and branded formulation of MMF 500 mg, and found that the two formulations met the European regulatory criteria for bioequivalence 4.
• The pharmacokinetics and pharmacodynamics of MMF have been extensively studied, with a focus on its metabolism, safety, and tolerability 5, 6, 7.
• MMF has been shown to be effective in reducing the incidence and severity of acute rejection episodes in kidney transplant recipients, and has also been used in combination with other immunosuppressive agents to reduce or avoid exposure to steroids or calcineurin inhibitors 6.

Efficacy and Safety

• The efficacy and safety of MMF 500 mg BID have been demonstrated in various clinical trials, with a focus on its use in preventing organ rejection in transplant patients 3, 4, 5, 6, 7.
• MMF has been shown to be well-tolerated, with common adverse events including gastrointestinal disorders, neutropenia, and thrombocytopenia 5, 6.
• The drug has also been found to be effective in reducing the incidence and severity of acute rejection episodes in kidney transplant recipients, and has also been used in combination with other immunosuppressive agents to reduce or avoid exposure to steroids or calcineurin inhibitors 6.

Clinical Applications

• MMF 500 mg BID has been approved for the prophylaxis of allograft rejection after renal, cardiac, or liver transplant 7.
• The drug has also been studied in other clinical applications, including lung and simultaneous pancreas/kidney transplants, and has shown encouraging results 7.
• Additionally, MMF has been found to have potential in the treatment of autoimmune diseases, such as lupus, myasthenia gravis, and glomerular disorders 7.