Choice of initial therapy for idiopathic retroperitoneal fibrosis (RPF)

* Refer to the UpToDate topic on major side effects of systemic glucocorticoids for pretreatment considerations and review of contraindications to glucocorticoids.
¶ Initial doses of alternate immunosuppressive agents:

• Oral methotrexate: 7.5 to 10 mg once weekly; increase by 2.5 mg per week until a maximum dose of 20 mg once per week.
• Oral mycophenolate mofetil: 1000 mg twice daily.
• Intravenous rituximab: 375 mg/m² once per week for 4 weeks or 1 g every 2 weeks for 2 doses.