Clinical scenario: Nephrotic syndrome | Cyclophosphamide | Neutropenia
A 7-year-old girl with steroid-dependent nephrotic syndrome is started on oral cyclophosphamide to reduce steroid requirement. After 3 weeks of treatment, she presents with fever and lethargy. Her investigations show:
- Total leukocyte count: 1.2 × 10⁹/L
- Absolute neutrophil count: 400/µL
- Platelets: normal
What is the most appropriate next step?
A. Continue cyclophosphamide
B. Stop cyclophosphamide
C. Increase prednisolone dose
D. Start granulocyte colony-stimulating factor
E. Switch to mycophenolate
Correct answer & Explanation:
Correct answer: B. Stop cyclophosphamide
Explanation:
This child has cyclophosphamide-induced neutropenia, a known dose-related adverse effect.
Management:
- Stop cyclophosphamide immediately
- Monitor complete blood count regularly
- Treat infection promptly if febrile neutropenia develops
- Restart or switch therapy only after recovery and specialist review
Why other options are incorrect:
- Continue cyclophosphamide → increases risk of severe infection.
- Increase prednisolone → does not correct drug-induced neutropenia.
- G-CSF → not routinely required in uncomplicated drug-induced neutropenia.
- Mycophenolate → may be considered as an alternative steroid-sparing agent but not during acute neutropenia.
Key point:
In children receiving cyclophosphamide for steroid-dependent nephrotic syndrome, ANC <500/µL is a serious toxicity → stop the drug.
