Cost analysis of once-daily ISMN versus twice-daily ISMN or transdermal patch for nitrate prophylaxis

Objective: To compare the costs and outcomes of treating exercise‐induced angina with once or twice‐daily isosorbide mononitrate (ISMN) or transdermal patch.Method: A decision‐analytic model was designed based on published literature showing compliance and increasing symptoms and estimates from physicians on treatment patterns and worsening symptoms.Results: Data show that patients are more compliant with once‐daily ISMN (Imdur®, Astra Hässle, Mölndal, Sweden) and patch regimens than with twice‐daily dose. Based upon the assumption that more compliant patients are better controlled, the model found that fewer medical care resources were consumed by patients treated with the once‐daily and the patch regimens. The unit cost of the twice‐daily ISMN regimen is 40% of the unit cost of the once‐daily. Annual costs of treating an exercise‐induced angina patient are £248 for Imdur® compared to £250 for the twice‐daily ISMN and £299 for the transdermal patch.Conclusion: Unit prices alone are not good indicators for estimating medical management costs.