MMF versus MPA Sodium for Lupus Nephritis
Both mycophenolate mofetil (MMF) and enteric-coated mycophenolic acid sodium (eMPA/MPA sodium) are equally efficacious for treating lupus nephritis and can be used interchangeably, with 720 mg of eMPA being roughly equivalent to 1 g of MMF. 1
Evidence for Equivalence
The EULAR/ERA-EDTA guidelines explicitly state that either MPA formulation can be used in treatment of lupus nephritis based on:
- Evidence from transplantation medicine demonstrating comparable efficacy between the two formulations 1
- A single randomized controlled trial in lupus nephritis showing MMF and enteric-coated mycophenolic acid sodium are likely equally efficacious 1
Dose Equivalency
The conversion ratio is straightforward: 720 mg of eMPA equals approximately 1 g of MMF. 1
For standard lupus nephritis dosing:
- MMF target dose: 2-3 g/day (induction therapy for Class III/IV) 1, 2
- Equivalent eMPA dose: 1.44-2.16 g/day 1, 2
Practical Selection Between Formulations
Since efficacy is equivalent, the choice between MMF and MPA sodium should be based on:
- Gastrointestinal tolerability: The enteric-coated formulation (eMPA) may theoretically offer better GI tolerability, though this is not definitively established in lupus nephritis trials 1
- Availability and cost: Local formulary considerations may dictate which formulation is accessible 1
- Patient preference: If a patient experiences GI side effects on one formulation, switching to the other is reasonable 1
Critical Dosing Considerations
Regardless of which formulation you choose:
- Target the same therapeutic exposure: Both should achieve an MPA-AUC₀₋₁₂ of 60-90 mg*h/L for optimal outcomes 2
- Adjust doses based on tolerance, adverse effects, and efficacy 1
- Always combine with glucocorticoids: Pulse IV methylprednisolone (500-2500 mg total) followed by oral prednisone 0.3-0.5 mg/kg/day, tapering to ≤7.5 mg/day by 3-6 months 1, 2
Common Pitfall to Avoid
Do not assume one formulation is superior to the other for efficacy—the evidence shows they are equivalent when dosed appropriately. 1 The 2012 EULAR/ERA-EDTA committee explicitly stated that "either MPA formulation can be used" while awaiting further validation, and this recommendation has been maintained in subsequent updates. 1