Subcutaneous continuous infusion of ifosfamide and cyclophosphamide in ambulatory cancer patients: bioavailability and feasibility

Using cyclophosphamide in inflammatory rheumatic diseases

Cyclophosphamide (CYC), primarily introduced into clinical practice as an anti-cancer substance, is a potent immunosuppressive drug. Today, it is used in a number of organ- or life -threatening autoimmune diseases such as systemic vasculitides or connective tissue diseases. While being effective, CYC has a small therapeutic index and is associated with significant toxicity. CYC has been used in oncology in a variety of diseases and a lot of data has been derived from this area. This knowledge is often extrapolated to the rheumatologic settings. However, besides some similarities substantial differences between these two specialties considering the underlying diseases as well as the kind of application of the drug exist. The aim of the present review is to describe the general characteristics of the use of CYC from the rheumatologist's point of view, including pharmacologic and pharmacokinetic properties, drug interactions, toxicity and possible preventive and/or therapeutic measures; all of which are important to consider when using this particular drug in the treatment of inflammatory rheumatic diseases.

Comparison of continuous infusion and bolus administration of ifosfamide in children

The pharmacological effects of ifosfamide (IFO) are dependent on its metabolism which may vary between different modes of administration. This was studied in 17 patients who received both a continuous infusion (9 g/m2 over 72 h) and repeated bolus administration (3 g/m2 every 24 h for 3 days). Concentrations of IFO and its metabolites were determined in plasma and urine. There was up to 70% less of the dechloroethylated metabolites in plasma following bolus administration compared to continuous infusion. Since dechloroethylation results in the formation of the toxic metabolite chloroacetaldehyde, this difference in metabolism may have an impact on the toxicity of IFO. There were no other consistent differences between the two modes of administration. Auto-induction of IFO metabolism, with an increase in dechloroethylated metabolites, was observed for both modes of administration. In conclusion, apart from dechloroethylation, there is little difference between these two modes of administration. However, during multiple cycles of IFO therapy such differences could have a significant effect.