In general, Isosorbide Dinitrate does not cause significant side effects, but in some patients, it may cause headaches, which usually occur in daily dose of ≥40 mg. However, the headache will subside if the dose is reduced to 1/2 tablet 3 times daily, and will not recur even if the dose is increased again after a few days. With long-term treatment with Isosorbide Dinitrate, sensitivity to headaches will disappear without the need for dose adjustments, and the effect of vasodilation on the heart's blood vessels will not be reduced.