 - Within 2 weeks prior to randomization use of any of the following medications that may result in drugdrug interactions with aminopterin: methotrexate, trimethoprim with or without sulfamethoxazole; sulfonamides; sulfonylureas; pyrimethamine; triamethamine; dipyridamole; colchicine; probenecid; aminoglycosides; theophylline; phenytoin; and folinic acid i.e., leucovorin unless prescribed by the investigator to treat study drug related toxicity. 