ANCA Vasculitis / Nephrotic Syndrome Pregnancy: Avoid — rituximab causes fetal B-cell depletion; effective contraception during and for 12 months after treatment

Rituximab (Nephrology)

Brand names: MabThera, Rixathon, Ruxience

Adult dose

Dose: ANCA vasculitis: 375 mg/m2 IV weekly x4 OR 1000 mg IV x2 doses 2 weeks apart. Nephrotic syndrome (steroid-resistant): per protocol.

Route: Intravenous infusion (slow — over 4-6 hours for first infusion)

Frequency: Per protocol — induction then maintenance

Max: Per specialist protocol

Anti-CD20 monoclonal antibody. Pre-medicate with paracetamol, antihistamine, and IV methylprednisolone 100 mg before each infusion. PCP prophylaxis (co-trimoxazole) mandatory if on concurrent cyclophosphamide.

Paediatric dose

Dose: 375 mg/m2/kg

Route: IV infusion

Frequency: Per protocol (1-4 doses)

Max: Per protocol

Used in paediatric steroid-resistant/dependent nephrotic syndrome. KDIGO 2021 recommends rituximab for steroid-dependent nephrotic syndrome in children. Specialist only.

Dose adjustments

Renal

No dose adjustment required — not renally excreted

Hepatic

No dose adjustment required

Paediatric weight-based calculator

Patient weight (kg)

Used in paediatric steroid-resistant/dependent nephrotic syndrome. KDIGO 2021 recommends rituximab for steroid-dependent nephrotic syndrome in children. Specialist only.

Clinical pearls

RITUXVAS trial (Jones et al. NEJM 2010): rituximab + low-dose cyclophosphamide vs standard cyclophosphamide in ANCA vasculitis — non-inferior remission at 12 months
RAVE trial (Stone et al. NEJM 2010): rituximab non-inferior to cyclophosphamide for induction; SUPERIOR in relapsing ANCA vasculitis
MAINRITSAN trial: rituximab maintenance superior to azathioprine for relapse prevention in ANCA vasculitis at 28 months
Hepatitis B screening mandatory (HBsAg + anti-HBc) before rituximab. HBsAg+: antiviral prophylaxis and hepatology review. Anti-HBc+ (resolved HBV): monitoring or prophylaxis depending on risk stratification.
Immunoglobulin monitoring: IgG levels before each cycle; IgG <3 g/L = consider IVIG replacement; severe hypogammaglobulinaemia = serious infection risk

Contraindications

Active severe infection
Hepatitis B (screen before use — reactivation risk)
Live vaccines within 4 weeks
Hypersensitivity to murine proteins

Side effects

Infusion reactions (flushing, hypotension, bronchospasm — mainly first infusion)
B-cell depletion with hypogammaglobulinaemia
PML (JC virus — rare)
Hepatitis B reactivation (fatal cases reported)
Serious infections

Interactions

Live vaccines — avoid within 4 weeks before and 12 months after rituximab
Natalizumab — increased PML risk; avoid combination

Monitoring

IgG levels (baseline and before each cycle)
FBC
Hepatitis B status (baseline)
eGFR/urinalysis
ANCA titres
Infection signs

Reference: BNFc; BNF 90; RITUXVAS (Jones et al. NEJM 2010); RAVE (Stone et al. NEJM 2010); MAINRITSAN Trial; KDIGO 2021 Glomerulonephritis; SPC MabThera. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways