Donepezil and Vitamin E to Prevent Side Effects Caused By Radiation Therapy to the Head in Patients Receiving Treatment for Small Cell Lung Cancer

DISEASE CHARACTERISTICS:

* Diagnosis of small cell lung cancer (SCLC)

  * Must meet one of the following conditions:

    * Enrolled no more than 4 weeks before initiation of prophylactic cranial irradiation (PCI) OR
    * Enrolled no more than 10 days after initiation of PCI
  * Limited or extensive stage SCLC with complete response (CR) outside chest allowed
* Must have CR or minimal disease after completion of intended course of chemotherapy
* No disease progression since initiation of PCI
* No prior or concurrent CNS metastases

PATIENT CHARACTERISTICS:

Age:

* 18 and over

Performance status:

* ECOG 0-2

Life expectancy:

* At least 12 weeks

Hepatic:

* Bilirubin no greater than 1.5 mg/dL

Renal:

* Creatinine no greater than 2 times upper limit of normal

Cardiovascular:

* No sick sinus syndrome or other symptomatic supraventricular conduction disorders even if symptoms currently controlled by antiarrhythmics

Pulmonary:

* No history of asthma or chronic obstructive pulmonary disease requiring chronic oxygen therapy

Other:

* No medical or psychiatric condition that would increase risk
* No seizure disorder
* No ongoing alcohol abuse

PRIOR CONCURRENT THERAPY:

Chemotherapy:

* See Disease Characteristics
* No concurrent anticancer chemotherapy

Other:

* No concurrent medications that would impair baseline cognitive function or are likely to be dose escalated over the next few months
* No other concurrent vitamin E