From the Guidelines
The dose of Mycophenolate Mofetil (MMF) is approximately 1300 mg/m2 per day, which can be translated to a dose of around 30-40 mg/kg per day, with a maximum of 2000 mg per day in children, as stated in the american society of hematology 2019 guidelines for immune thrombocytopenia 1.
Key Considerations
- The dose of MMF may vary depending on the specific indication, patient's renal function, concomitant medications, and tolerance to side effects.
- MMF is converted to its active form, mycophenolic acid, which inhibits inosine monophosphate dehydrogenase, an enzyme necessary for purine synthesis primarily in lymphocytes, and thereby inhibits DNA synthesis of T and B cells 1.
- The effect of MMF in immune thrombocytopenia is relatively slow, with responses of ∼15% at 1 week but with a response by 1 month in roughly one-half of the treated patients, with durable response of 56.7% to 61.9% 1.
Important Side Effects
- Diarrhea is a common side effect (6.8%) of MMF, more so than with azathioprine 1.
- Other significant side effects include neutropenia, anemia, and viral infections; with prolonged use, there is a small increased risk of malignancy and progressive multifocal leukoencephalopathy 1.
- MMF is also associated with pure red aplasia and is a teratogen, and should not be used during pregnancy or lactation 1.
From the Research
Mycophenolate Mofetil (MMF) Dosing
- The dose of Mycophenolate Mofetil (MMF) can vary based on the specific medical condition being treated and the patient's weight.
- According to the study 2, when used in conjunction with post-transplant cyclophosphamide (PTCy), MMF is dosed at 15 mg/kg three times daily up to a maximum dose of 3 g/day.
- This means that patients who weigh ≥67 kg receive 3 g/day, which translates to a variable dose/kg of MMF.
- The study 2 also stratified MMF dose relative to patient actual body weight (mg/kg/day) into categories of low (<29 mg/kg/day), low intermediate (29-34 mg/kg/day), high intermediate (35-41 mg/kg/day), and high (>41 mg/kg/day).
- However, the initial recommended dosage of MMF is 1 g twice daily, as stated in the study 3, which does not provide a direct dose in mg/kg.
MMF Dosing Considerations
- The pharmacokinetics of mycophenolic acid, the active moiety of MMF, show large between-patient variability, and exposure to mycophenolic acid correlates with the risk for acute rejection 4.
- This suggests that individualization of MMF dose may be necessary to optimize clinical outcomes.
- The study 5 found that patients with higher mycophenolic acid area under the curve (AUC) values had better renal function, despite no difference in cyclosporine dose or blood levels.
- However, the optimal dose of MMF in mg/kg has not been consistently established across studies, and more research is needed to determine the ideal dosing strategy.