Donepezil in Treating Patients Who Have Undergone Radiation Therapy for Brain Tumors

INCLUSION CRITERIA:

* Adults \>18 years old.
* Life expectancy of at least \> 30 weeks.
* Must have received a prior course of at least 30 Gy fractionated whole or partial brain irradiation for treatment of a primary brain tumor or metastatic disease to the brain.
* Must have completed radiation \> 6 months prior to enrollment and have no radiographic evidence of brain disease, or stable brain disease defined as no evidence of tumor progression in the 3 months prior to enrollment.
* Patients who have undergone one or more treatments with single fraction stereotactic radiosurgery (SRS) in addition to whole or partial brain irradiation are eligible, as long as the SRS was completed \> 6 months prior to registration if NED or stable disease.
* Radiation treatment records must be available for all prior radiation treatments (external beam and/or SRS).
* Patients who have received PCI (prophylactic cranial irradiation) are eligible.
* Karnofsky Performance Status must be \> 60 or ECOG 0-2.
* Treatment with steroids, anti-cholinergics, anti-epileptics, anti-depressants, and /or sedatives/benzodiazepines is acceptable, but the patient must be on a stable or decreasing dose at the time of study entry.
* Patients using narcotic analgesics on a stable dose and/or prn basis are eligible.
* Patients currently on a stable dose of Methylphenidate or Dextramphetamine are eligible.
* For patients with brain metastases, if extracranial primary or metastatic disease is present, it must have responded to local and/or systemic treatment. Must be stable in the 3 months prior to enrollment.
* Must not be receiving chemotherapy at the time of enrollment.
* Patient must not have any planned therapy, including surgery, brain radiation of any type, chemotherapy, or immunotherapy during the next 30 weeks for brain or extracranial primary metastatic disease.
* Hormonal therapy for patients with breast or prostate cancer is acceptable.
* Breast patients receiving therapy with Herceptin are allowed.
* Patients must be able to give informed consent to participate in the study, including signing the consent form.
* Patients must have a telephone.

EXCLUSION CRITERIA:

* Patients cannot be currently taking dementia drugs, cognitive enhancers, neuroleptics, and/or anti-parkinsonian agents. For patients who have used these drugs in the past, they must not have used them in the 2 weeks prior to enrolling on the study.
* Hypersensitivity to donepezil.
* Patients may not currently be taking Ketoconazole or Quindine
* Arrythmias including bradycardia or heartblock
* Patients who have received, GliaSite or other type of brain brachytherapy, (Gliadel Wafers permitted) convection enhanced delivery of immunotoxins, and/or any other investigational modalities for treatment of their brain tumor. The effects of donepezil on the developing human fetus at the recommended therapeutic dose are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately.
* It is unknown whether donepezil is excreted in breast milk, for this reason women who are currently breast-feeding are not eligible for this study.