- Patients are taking stable dose of methotrexate and at least 10mg folic acid per week for at least 4 weeks. Rituximab is administrated as 1000mg intravenous infusion on day 1 and day 15. Premedication as standard prescription consists of methylprednisolone 100mg IV, Chlorpheniramine maleate(piriton 10mg IV and oral paracetamol 500mg to be given 30 minutes before each infusion of rituximab. Oral prednisolone 60mg is tob e given from day 1-6 after rituximab infusion and 30mg from day 7-13.