Mycophenolate Mofetil (MMF) Dosage for Preventing Organ Rejection
The typical dosage of mycophenolate mofetil (MMF) for preventing organ rejection is 1 g twice daily (2 g total daily dose), which is the standard recommended initial dose for solid organ transplantation. 1
Mechanism of Action and Indication
- MMF is a prodrug of mycophenolic acid that acts as an immunosuppressant by inhibiting inosine monophosphate dehydrogenase, which blocks de novo purine synthesis and induces apoptosis in lymphocytes 1
- It is specifically indicated for the prevention of organ rejection in solid organ transplants and is also a standard component of graft-versus-host disease (GVHD) prophylaxis regimens 1
Standard Dosing Regimens
- For adult patients receiving solid organ transplants, the recommended initial dosage is 1 g twice daily (2 g total daily dose) 1, 2
- In clinical trials, MMF has been studied at doses ranging from 2-3 g per day, with the 2 g daily dose showing a favorable balance between efficacy and side effects 3
- For renal transplantation, doses of 2-3 g daily have demonstrated significant reduction in acute rejection episodes compared to azathioprine 3, 4
Dosage Considerations for Special Populations
- For pediatric patients, dosing may be calculated based on body surface area, with suggested dosing of 600-1200 mg/m² 1
- In patients with renal insufficiency, dose adjustments may be necessary as MMF's metabolites are primarily excreted through the kidneys 1
Administration and Formulations
- MMF is available in oral suspension, capsules, and tablets 1
- The medication is typically administered twice daily 1
- For patients who cannot tolerate oral administration, intravenous formulations may be used at equivalent doses 1
Monitoring and Efficacy
- Some clinicians monitor mycophenolic acid (MPA) levels to ensure therapeutic efficacy, with target predose MPA levels greater than 2 μg/ml 5
- Patients with average predose MPA levels less than 3 μg/ml may be more likely to experience treatment failure 5
- Regular monitoring of complete blood counts is essential due to potential hematologic side effects 1
Common Side Effects and Precautions
- The most common adverse effects are gastrointestinal, including nausea, vomiting, and abdominal cramping 1, 2
- Hematologic complications (anemia, leukopenia, thrombocytopenia) may occur and require monitoring 1
- Increased susceptibility to viral and bacterial infections is a significant concern, particularly in transplant patients 1
- Women of childbearing potential should use reliable contraception as MMF is teratogenic 1
Clinical Outcomes
- In transplant recipients, MMF has demonstrated significant reduction in acute rejection episodes compared to azathioprine 3, 4
- The clinical benefit was greatest with a dose of 3 g/day, but gastrointestinal effects, cytomegalovirus infections, and malignancies were slightly more common at that dose 3
- The appropriate dose may lie between 2 g and 3 g per day and may require individualization based on clinical response and tolerability 3