Cyclophosphamide

• Severe/organ-threatening lupus nephritis or vasculitis unresponsive to other agents — specialist-led only

DNA cross-linking alkylating agent → cytotoxic to rapidly dividing cells, including lymphocytes.

• Stop ≥3 months before planned conception (both partners)
• Dose- and age-dependent infertility — counsel on fertility preservation first
• Teratogenic — avoid in all trimesters

Non-pregnant (severe flare)

Specialist protocol — IV pulses, e.g. Eurolupus regimen

• AbsolutePregnancy — teratogenic
• AbsoluteBreastfeeding

• Haemorrhagic cystitis
• Marrow suppression
• Infertility (dose/age-dependent, can be irreversible)
• ↑ malignancy risk long-term

• • Only ever used in pregnancy for genuinely organ- or life-threatening maternal disease where no alternative exists — MDT/specialist decision, not routine care.

• Allopurinol

  Avoid

  ↑ myelosuppression

• 💡 Counsel on fertility preservation (e.g. GnRH agonist co-treatment, egg/embryo freezing) before use in women of reproductive age when time allows.