OBJECTIVE: To analyze the utilization patterns of sidenafil citrate in a senior managed care population. METHODS: Using a large managed care administrative claims database, all male patients with a prescription for sidenafil citrate from December 2003 through November 2004 were selected from among patients ages 18 years and older (n= 107,879). A diagnosis for erectile dysfunction (ED) was not required. Prevalence, age, number of prescriptions and days supply, per senior member per month (PSMPM) cost, concomitant medications, and cost by diagnosis were analyzed. The PSMPM of sildenafil was compared with antihistamines and proton pump inhibitors (PPI's). RESULTS: The median age of sildenafil users overall was 52 years old and overall per member per month cost was $0.16. Patients ages 65 and older (65+) represented 11.5% of all sidenafil use in the study (n=12,383). 4.0% of eligible 65+ members had at least one prescription for sidenafil compared with 2.5% of members younger than 65. The average age of senior sildenafil users was 69.5 years old with 62.9% of seniors between 65-69 years of age; 23.5% were 70-74, and 3.5% were 80 years of age and older. Over the year, seniors filled 33,800 sidenafil prescriptions (mail order and retail) representing 242,552 pills. The average PSMPM cost for sidenafil was $0.39 compared with $9.52 for PPI's and $1.35 for antihistamines. CONCLUSIONS: The prevalence of treated ED patients in a senior managed care population is 60% higher than that of younger members ages 18-64. The cost of sidenafil use in senior males is relatively low.