3-AP and Gemcitabine as Second-Line Therapy in Treating Patients With Stage III or Stage IV Recurrent Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed\* non-small cell lung cancer (NSCLC) * Stage III or IV disease * One of the following cellular types: * Adenocarcinoma * Non-diffuse bronchoalveolar cell carcinoma * Large cell carcinoma * Squamous cell carcinoma NOTE: \*A repeat biopsy of any accessible tumor site is required if \> 5 years have elapsed since the initial diagnosis * Progressive disease after 1 prior gemcitabine-containing chemotherapy regimen for stage III or IV NSCLC and must have achieved, at least once, a partial response, complete response, or stable disease during therapy * Not a primary non-responder and experienced only progressive disease during gemcitabine-containing chemotherapy * Measurable disease * At least 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan * No known brain metastases PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 OR * Karnofsky 60-100% Life expectancy * Not specified Hematopoietic * WBC ≥ 3,000/mm\^3 * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * No glucose-6-phosphate dehydrogenase (G6PD) deficiency Hepatic * Bilirubin ≤ 1.5 times upper limit of normal (ULN) * ALT ≤ 2.5 times ULN (5 times ULN if liver metastases are present) Renal * Creatinine ≤ 1.5 times ULN OR * Creatinine clearance ≥ 50 mL/min Cardiovascular * No prior uncontrolled cardiac disease * No myocardial infarction within the past 12 months * No symptomatic congestive heart failure * No coronary artery disease * No cardiac arrhythmia Pulmonary * No uncontrolled symptomatic pulmonary disease * No pulmonary disease that requires oxygen therapy Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No other malignancy within the past 5 years except completely treated carcinoma in situ of the cervix or nonmelanoma skin cancer * No prior allergic reaction attributed to compounds of similar chemical or biological composition to study agents * No other concurrent uncontrolled illness * No psychiatric illness or social situation that would preclude study compliance PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * See Disease Characteristics * More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered Endocrine therapy * Not specified Radiotherapy * More than 4 weeks since prior radiotherapy and recovered Surgery * Not specified Other * No concurrent combination antiretroviral therapy for HIV-positive patients * No other concurrent investigational agents * No other concurrent anticancer agents or therapies