Table 1: Recommended first-line agents in the preventive treatment of NMO.

MedicationInitial dosing RegimenMaintenance dosing regimenMonitoring guidelines

Azathioprine (AZA)2 mg/kg/day p.o., divided into 2 daily doses(i) Increase to 3 mg/kg/day p.o. if unsatisfactory response
(ii) Add prednisone 20–30 mg p.o. daily if unsatisfactory response
(iii) Switch to alternate immunosuppressive agent if unsatisfactory response
(i) TPMT genotyping: avoid use in TPMT positive patients
(ii) CBC and differential baseline and qweekly × 4, qbiweekly × 2, then q1-2 months, LFTs q3months

Mycophenolate mofetil (MMF)500 mg p.o. bid(i) Titrate up to 1000 mg p.o, bid over 4 weeks
(ii) Check WBC count and differential at 4 weeks: target total WBC = 3-4 × 103/μL or absolute lymphocyte count =1–1.2 × 103/μL
(iii) If target WBC or lymphocyte count unattained, increase dose by 250 mg p.o. bid every 2 weeks to maximum dose of 1500 mg p.o. bid
(iv) Administer prednisone at 20–30 mg p.o. daily while titrating up MMF, wean off prednisone over 6–8 weeks once target dose attained
(v) Switch to alternate immunosuppressive agent if target WBC/lymphocyte count not attained or unsatisfactory clinical response
(i) CBC and differential at baseline and qweekly × 4, then qmonthly × 6 months, then q6monthly
(ii) LFTs at baseline and qmonthly × 6 months, then q6monthly
(iii) If clinical suspicious for infection: septic work-up, including CSF JC virus if suspicious for PML

Rituximab1000 mg iv × 1 dose(i) Repeat 1000 mg iv × 1 dose 2 weeks after initial dose
(ii) Check CD19/20 cell counts monthly
(iii) Redose with same double dose (1000 mg iv × 1, followed by repeat dose 2 weeks later) when CD19/20 cell counts > 0.1% total lymphocyte count
(iv) If CD19/20 counts are undetectable 6 months after last dose, redose with single 1000 mg iv dose
(i) Baseline and monthly CBC and differential, CD19/20 cell count
(ii) Baseline and periodic renal function tests
(iii) Screen for hepatitis B in high-risk patients prior to initiation