Imdur Drug Class
Imdur (isosorbide mononitrate) is a long-acting organic nitrate vasodilator. 1
Pharmacological Classification
Imdur belongs to the nitrate class of cardiovascular medications, specifically functioning as an organic nitrate that acts as a vasodilator with effects on both arteries and veins. 1
Mechanism of Action
The drug works through the following mechanisms:
Relaxation of vascular smooth muscle producing dilatation of peripheral arteries and veins, with predominant effects on venous circulation. 1
Promotes nitric oxide release, which serves as an exogenous source to replenish or restore the actions of endothelium-derived relaxing factor. 2
Reduces preload through venous dilatation, which promotes peripheral pooling of blood and decreases venous return to the heart, thereby reducing left ventricular end-diastolic pressure. 1
Reduces afterload through arterial vasodilation, which reduces systemic vascular resistance and mean arterial pressure. 1
Dilates coronary arteries, though the relative importance of this effect compared to preload and afterload reduction remains undefined. 1
Formulation Characteristics
Imdur is specifically an extended-release formulation of isosorbide mononitrate that provides a prolonged duration of action lasting 12 to 24 hours when dosed once daily. 2, 3 The controlled medication release is achieved using the Durules principle of insoluble matrix embedding. 3
Clinical Context
Isosorbide mononitrate is the major biologically active metabolite of isosorbide dinitrate, and most of the clinical activity of the dinitrate is attributable to the mononitrate. 1 Unlike oral isosorbide dinitrate, isosorbide mononitrate is not subject to first-pass metabolism and has approximately 100% bioavailability. 1