OBJECTIVES: I. Determine the maximum tolerated dose of ZD 1839 given intermittently or continuously and concurrently with standard doses of carboplatin and paclitaxel in patients with advanced non-small cell lung cancer. II. Determine the safety of ZD 1839 in these regimens in these patients. III. Determine whether the exposure of either free carboplatin or paclitaxel in an established treatment regimen is significantly altered by the addition of oral ZD 1839 in this patient population. IV. Determine the exposure of ZD 1839 before and after standard doses of carboplatin and paclitaxel to assess whether ZD 1839 steady state is significantly altered by coadministration of chemotherapy.