Drug Class Description
Adenosine deaminase inhibitors.

Generic Name
Pentostatin

Drug Description
One vial contains 10 mg Pentostatin.When reconstituted (see Section 6.6), the resulting solution contains pentostatin 2 mg/ml.

Presentation
Powder for solution for injection, powder for solution for infusion.The vials contain a solid white to off-white cake or powder. The pH of reconstituted solution is 7.0 – 8.2.

Indications
Pentostatin is indicated as single agent therapy in the treatment of adult patients with hairy cell leukaemia.

Adult Dosage
Pentostatin is indicated for adult patients.Administration to PatientIt is recommended that patients receive hydration with 500 to 1,000 ml of 5% glucose only or 5% glucose in 0.18% or 0.9% saline or glucose 3.3% in 0.3% saline or 2.5% glucose in 0.45% saline or equivalent before pentostatin administration. An additional 500 ml of 5% glucose only or 5% glucose in 0.18% or 0.9% saline or 2.5% glucose in 0.45% saline or equivalent should be administered after pentostatin is given.The recommended dosage of pentostatin for the treatment of hairy cell leukaemia is 4 mg/m2 in a single administration every other week. Pentostatin may be given intravenously by bolus injection or diluted in a larger volume and given over 20 to 30 minutes.Higher doses are not recommended.No extravasation injuries were reported in clinical studies.The optimal duration of treatment has not been determined. In the absence of major toxicity and with observed continuing improvement, the patient should be treated until a complete response has been achieved. Although not established as required, the administration of two additional doses has been recommended following the achievement of a complete response.All patients receiving pentostatin at 6 months should be assessed for response to treatment. If the patient has not achieved a complete or partial response, treatment with pentostatin should be discontinued.If the patient has achieved a partial response, pentostatin treatment should be continued in an effort to achieve a complete response. At any time after a complete response is achieved, two additional doses of pentostatin are recommended. Pentostatin treatment should then be stopped. If the best response to treatment at the end of 12 months is a partial response, it is recommended that treatment with pentostatin be stopped.Withholding or discontinuation of individual doses may be needed when severe adverse reactions occur. Drug treatment should be withheld in patients with severe rash, and withheld or discontinued in patients showing evidence of nervous system toxicity.Pentostatin treatment should be withheld in patients with active infection occurring during the treatment but may be resumed when the infection is controlled.Dosage in Patients with CytopeniasNo dosage reduction is recommended at the start of therapy with pentostatin in patients with anaemia, neutropenia, or thrombocytopenia. In addition, dosage reductions are not recommended during treatment in patients with anaemia and thrombocytopenia. Pentostatin should be temporarily withheld if the absolute neutrophil count during treatment falls below 200 cells/mm3 in a patient who had an initial neutrophil count greater than 500 cells/mm3 and may be resumed when the count returns to predose levels.Renal InsufficiencyThere is limited experience in patients with impaired renal function (creatinine clearance (Clcr) <60 ml/min)