Outcomes and Cost Savings of an ACE Inhibitor Therapeutic Interchange

OBJECTIVE: To determine the cost-effectiveness and outcomes of a therapeutic interchange from captopril, enalapril, or lisinopril to quinapril for 36 patients with mild-to-moderate hypertension. DESIGN: A three-month, open-label, nonrandomized therapeutic interchange trial performed from September 1995 through July 1996. SETTING: University-affiliated outpatient clinics. RESULTS: Outcomes at minimum follow-up of three months indicated that 35 of 36 patients (97%) were successfully switched to quinapril with similar blood pressure control. Four of the 36 patients (11%) complained of a cough while on quinapril; however, these patients also experienced coughing on their previous ACE inhibitor therapy. At the same time, three other patients who had side effects on their previous ACE inhibitor therapy did not have a recurrence of side effects on quinapril. A cost savings of $4,956 per year for these 36 patients during the first year of follow-up was projected. CONCLUSION: Switching patients with mild-to-moderate hypertension stabilized on captopril, enalapril, or lisinopril to quinapril is cost effective. However, therapeutic interchange programs involving other drug classes with indications in other disease states must be evaluated individually to assess their cost effectiveness.