Table 2 G-CSF

Physiological role

cytokine glycoprotein stimulating differentiation, release and survival of neutrophils and other granulocytes

Drug

Filgrastim (recombinant G-CSF) has been available since the early 1990’s; originally to treat patients with chemotherapy-induced neutropenia

Current usage

Severe chronic neutropenia, mobilisation of haematopoietic progenitors for stem cell transplantation [49,50,51], drug induced neutropenia [52].

G-CSF and clozapine rechallenge after CIN / CIA

Multiple case reports [49, 53,54,55,56,57,58,59,60,61,62,63,64,65] reviewed by Lally et al [66, 67]; G-CSF successfully supported over 70% of initial CIN cases. Success was markedly reduced following CIA.

Common adverse effects and management

Flu like symptoms, bone pain, headache, pyrexia and fatigue.

Rare adverse effects

Splenic rupture, glomerulonephritis, alveolar haemorrhage, thrombocytopenia and capillary leak syndrome.

Side effect management and monitoring

Analgesia, monitoring for splenomegaly [68] and bone mineral density assessment [69].

Long term safety

Available from the 20,000 annual healthy volunteer peripheral blood donors. Initial concerns of increased leukaemia risk alleviated by long term follow up [70].

Dose,

We took advice from haematology colleagues. G-CSF dosages ranged between single as required injections of 15million units to 30 million units twice weekly.

Administration

Pre-loaded syringe for subcutaneous injection, volume < 1 ml

Storage

Refrigerated

Cost

UK approx. £50 ($65) per dose

Institutional / systemic factors

High cost novel drug in psychiatric practice. Treating teams likely to be unfamiliar with usage and this may not be supported by all mental health organisations.