This is a fluorinated nucleotide analogue of the antiviral vidarabine which acts as a purine antagonist antimetabolite.

Indications: Treatment of advanced B-cell chronic lymphocytic leukaemia for patients who either have failed or are intolerant of, first-line chemotherapy.

Cautions: dosage should be reduced in renal impairment and fludarabine should not be given if creatinine clearance is less than 30ml/minute. It should also be avoided in patients with decompensated haemolytic anaemia.

Contra-indications: Haemolytic anaemia; pregnancy & breast feeding.

Side effect: Myelosuppression which can be severe and cumulative; immuno-suppression is also common and co- trimoxazole is often used to prevent pneumocystis infection. Immune-mediated haemolytic anaemia, thrombocytopenia, and neutropenia are less common side effects.

Dose: By bolus injection or by IV infusion over 30 minutes in a usual dose of 25mg/m2 body-surface daily for 5 consecutive days. It may be given by mouth in a dose of 40mg/m2 daily for 5 consecutive days. Courses may be repeated every 28 days, usually for up to 6 cycles.