The pharmacokinetics of subcutaneous cytosine arabinoside in patients with acute myelogenous leukaemia.

1 The pharmacokinetics of subcutaneous cytosine arabinoside were compared with bolus intravenous injection and intravenous infusion in five patients with acute myelogenous leukaemia. 2 Subcutaneous cytosine arabinoside was rapidly absorbed and then declined biexponentially with initial and terminal half-lives similar to intravenous bolus injection. 3 Cytosine arabinoside levels declined rapidly after intravenous bolus and subcutaneous bolus injection, and fell below steady state infusion levels after a mean time of 40 min (intravenous bolus) and 100 min (subcutaneous injection).