As the number of elderly persons continues to increase, family physicians will be caring for more patients with Alzheimer's disease. The treatment plan for patients with this incurable illness should be directed at optimizing their physical and psychosocial functioning and supporting their caregivers. Tacrine is the first medication proven to ameliorate the symptoms of Alzheimer's disease. This drug has been approved by the U.S. Food and Drug Administration for use in patients with mild to moderate Alzheimer's disease as evidenced by a score between 10 and 26 on the Mini-Mental State Examination. Tacrine can produce modest dose-related improvements in cognitive function and global measures of patient function. Such improvements only occur in 25 percent of patients treated with tacrine. On discontinuation of the drug, the patient's cognitive function returns to the level that would be expected if no treatment had been given. Both the degree of cognitive improvement and the severity of cholinergic symptoms increase with higher doses of tacrine. Thus, patients receiving tacrine therapy must be monitored for both clinical efficacy and adverse effects of the medication.