Which statement indicates that isosorbide dinitrate is having the desired effect?

The statement that indicates isosorbide dinitrate is having the desired effect is the one where the person mentions having forgotten to take nitroglycerin during the day. This suggests that the patient's condition is being effectively managed and that they are experiencing fewer or no angina attacks, which is often the goal of using isosorbide dinitrate.

Isosorbide dinitrate is a long-acting nitrate used primarily to prevent angina pectoris. Its function is to dilate blood vessels and increase blood flow to the heart muscle. When patients do not need to use their nitroglycerin as often, it means that their symptoms are under better control, and they might not experience chest pain as frequently.

In contrast, the other statements imply ongoing symptoms or dependence on nitroglycerin for relief, which would suggest that the isosorbide dinitrate therapy may not be achieving its intended effect. For instance, taking sublingual nitroglycerin many times or needing it frequently indicates that the angina is not well-controlled, while experiencing chest pain regularly shows that the therapeutic objectives are not being met. Therefore, forgetting to take nitroglycerin can be seen as a positive indication of effective management