Introduction to the symposium on high-dose cytosine arabinoside

Cytosine arabinoside (Ara-C) was first introduced into clinical trial in 1963. Twenty years later the optimum dosage and schedule are still being sought. High dose regimens promise to improve upon the already impressive effectiveness of this antimetabolite against acute leukemia, and to increase its range of indications to include lymphomas and certain carcinomas. Pharmacological monitoring will play a key role in future clinical evaluations of high dose Ara-C.