Rituximab (Rheumatology)

Premedication: an anti-pyretic and an antihistamine (e.g. paracetamol and diphenhydramine) should always be given before each administration. In rheumatoid arthritis, GPA and MPA, premedication with 100 mg intravenous methylprednisolone should be completed 30 minutes prior to each rituximab infusion to reduce infusion-related reactions. In adult GPA or MPA, methylprednisolone given intravenously for 1 to 3 days at 1000 mg per day is recommended prior to the first rituximab infusion (the last methylprednisolone dose may be given on the same day as the first rituximab infusion), followed by oral prednisone 1 mg/kg/day (not to exceed 80 mg/day, tapered as rapidly as possible based on clinical need) during and after the 4-week induction course. Pneumocystis jirovecii pneumonia prophylaxis is recommended for adult and paediatric GPA/MPA patients and adult pemphigus vulgaris patients during and following treatment. Rheumatoid arthritis retreatment: evaluate at 24 weeks and retreat then if residual disease activity remains, otherwise delay until disease activity returns; clinical response is usually achieved within 16-24 weeks of an initial course and continued therapy should be carefully reconsidered if there is no evidence of benefit within this period. GPA/MPA maintenance should be initiated no sooner than 16 weeks after the last rituximab induction infusion, or (following induction with other standard-of-care immunosuppressants) during the 4-week period after disease remission, and patients should receive at least 24 months after achieving remission, up to 5 years in those at higher relapse risk. No dose reductions of rituximab are recommended. Patients must be given the patient alert card with each infusion. Check the label to ensure the correct formulation (intravenous versus subcutaneous) is given. Infusion rates - first infusion: recommended initial rate 50 mg/h, and after the first 30 minutes escalate in 50 mg/h increments every 30 minutes to a maximum of 400 mg/h; subsequent infusions: initial rate 100 mg/h, increased by 100 mg/h increments at 30 minute intervals to a maximum of 400 mg/h. Rheumatoid arthritis alternative faster schedule for second and subsequent 1000 mg infusions in patients who did not experience a serious infusion-related reaction, using the same concentration as previously (4 mg/ml in a 250 ml volume): initiate at 250 mg/hour for the first 30 minutes then 600 mg/hour for the next 90 minutes; this must not be used in patients with clinically significant cardiovascular disease including arrhythmias, or previous serious infusion reactions to any prior biologic therapy or to rituximab. Mild or moderate infusion-related reactions usually respond to a reduction in infusion rate; severe reactions (especially severe dyspnoea, bronchospasm or hypoxia) require immediate interruption, and infusion may only be resumed after complete resolution at no more than half the previous rate. Elderly (over 65 years): no dose adjustment required. Administer under close supervision of an experienced healthcare professional in an environment with full resuscitation facilities immediately available. Paediatric: severe active GPA or MPA (2 to under 18 years) induction of remission is 375 mg/m2 body surface area by intravenous infusion once weekly for 4 weeks - a body surface area dose, not a per-kg dose; prior to the first infusion, intravenous methylprednisolone should be given as three daily doses of 30 mg/kg/day (not to exceed 1 g/day), with up to three additional daily 30 mg/kg intravenous doses permitted, followed by oral prednisone 1 mg/kg/day (not to exceed 60 mg/day) tapered as rapidly as clinically needed. Rituximab should not be used under 2 years of age in severe active GPA or MPA. Safety and efficacy in paediatric patients aged 2 to under 18 years has not been established in indications other than severe active GPA or MPA. Verify paediatric dosing against a children's formulary. SPC section 4.5 (interactions) was not retrieved in this bundle and no US label was available - verify interactions against the full SPC.