Intravenous cyclophosphamide is the drug of choice for steroid dependent nephrotic syndrome.

BACKGROUND: Steroid dependency is a major problem seen after therapy for idiopathic nephrotic syndrome in childhood. Although there is consensus about the usage of cyclophosphamide (CYC) in frequent relapsers, there is still a controversy concerning its usage in steroid-dependent nephrotic syndrome (SDNS).
METHODS: In the present study, nineteen children with SDNS were treated with CYC: ten via the intravenous (i.v.) route, and nine via the oral route. Remission was then maintained with prednisolone. Oral CYC therapy consisted of CYC at a dose of 2 mg/kg per day for 12 weeks. Intravenous (i.v.) CYC therapy consisted of CYC 500 mg/m2 per month (with intravenous 3500 cc/m2 per 24 h one-third saline hydration) for 6 months.
RESULTS: The cumulative dose of CYC was 168 mg/kg in the oral group and 132 mg/kg in the IV group. Daily oral CYC dose was 1.96~0.31 mg/kg, whereas i.v. CYC dose was 0.73~0.03 mg/kg. Long-term complications and side-effects such as alopecia, infection and hemorrhagic cystitis were not observed in the i.v. CYC treated group. In the long term, the dosage of prednisolone that held remission after CYC, the annualized relapse rates and the subsequent relapse time were significantly better in the i.v. CYC group, and the number of patients in remission for 2 years was significantly higher in the i.v. treated group (P<0.05).
CONCLUSIONS: In SDNS, i.v. CYC has a long lasting effect with lower annualized relapse rates and longer subsequent relapse time with a lower steroid dosage required to maintain remission than oral CYC. The results of the present study showed the safety of the i.v. route, and it is the preferable treatment in noncompliant patients for its long lasting remission and simple and inexpensive follow up.