A retrospective analysis comparing the costs and cost effectiveness of amlodipine and enalapril in the treatment of hypertension.

A comparison of treatment costs and cost effectiveness was performed retrospectively by using patient-level data from a randomized, controlled, one-year clinical trial of amlodipine and enalapril in the treatment of mild-to-moderate hypertension. Unit costs of amlodipine and enalapril were applied to the daily dosages of individual patients to calculate the total costs and average costs per patient in each treatment group in the clinical trial on an intent-to-treat basis. Efficacy rates were used to calculate the average treatment costs per success in blood pressure control. Although not statistically significant, amlodipine treatment resulted in a higher efficacy (89.5%) vs. enalapril (85.2%). The average costs per amlodipine-treated patient were consistently lower (-$112.30) than for the enalapril-treated patient by week 50. Treatment with amlodipine resulted in an average cost per success of $609 per patient compared with $772 per enalapril-treated patient. A sensitivity analysis revealed that, in the treatment of mild-to-moderate hypertension over the 50-week treatment period, amlodipine would remain less costly than enalapril, with a decrease in the cost of enalapril of up to 17%, and would remain more cost effective, with a 21% decrease in the cost of enalapril.