ZD 1839 in Treating Patients With Glioblastoma Multiforme in First Relapse

DISEASE CHARACTERISTICS: * Histologically confirmed glioblastoma multiforme in first relapse PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 60-100% Life expectancy: * More than 12 weeks Hematopoietic: * WBC at least 3,000/mm\^3 * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic: * Bilirubin less than 1.5 times upper limit of normal (ULN) * AST/ALT no greater than 2.5 times ULN Renal: * Creatinine less than 1.5 times ULN Cardiovascular: * No symptomatic congestive heart failure * No unstable angina pectoris * No cardiac arrhythmia Other: * No other uncontrolled concurrent illness * No ongoing or active infection * No psychiatric illness or social situation that would preclude study compliance * No prior allergic reactions to compounds of similar chemical or biologic composition to ZD 1839 * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * Ocular inflammation must be fully treated before study entry PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered Endocrine therapy: * Must be on stable dose of steroids for at least 1 week Radiotherapy: * At least 4 weeks since prior radiotherapy and recovered Surgery: * At least 1 week since prior surgery Other: * No other concurrent investigational agents * No other concurrent anticancer therapy * No concurrent combination antiretroviral therapy for HIV * No concurrent enzyme-inducing anticonvulsant drugs