Product Overview
[Drug Name]
Generic Name: Isosorbide Mononitrate Sustained-Release Capsules (I)
Trade Name: Longxin Isosorbide Mononitrate Sustained-Release Capsules (I) 50mg x 20 capsules
[Main Ingredient]
Isosorbide Mononitrate
[Indications/Main Functions]
For the prevention of angina pectoris; treatment of persistent angina pectoris after myocardial infarction and coronary heart disease; combined with digitalis or diuretics for the treatment of chronic congestive heart failure
[Specifications]
50mg x 20 capsules
[Dosage and Administration]
Oral. 10-20mg twice daily.
[Adverse Reactions]
1. Nitrate-induced vasodilatory headache may occur initially, usually disappearing after several days of continuous use. 2. Facial flushing, dizziness, orthostatic hypotension, and reflex tachycardia may also occur. 3. Significant hypotension, bradycardia, exacerbated angina pectoris, and syncope may occasionally occur.
[Contraindications]
1. Contraindicated in patients with acute circulatory failure (shock, circulatory collapse). 2. Contraindicated in patients with severe hypotension (systolic blood pressure <90 mmHg). 3. Contraindicated in patients with acute myocardial infarction and low filling pressures (unless under continuous hemodynamic monitoring). 4. Contraindicated in patients with hypertrophic obstructive cardiomyopathy, constrictive pericarditis, or cardiac tamponade. 5. Contraindicated in patients with severe anemia, glaucoma, or increased intracranial pressure. 6. Contraindicated in patients with allergies to nitro compounds.
[Drug Interactions]
Combination use with other vasodilators, calcium antagonists, beta-blockers, antihypertensives, tricyclic antidepressants, and alcohol may potentiate the hypotensive effect of this drug class.
[Precautions]
1. In patients with acute myocardial infarction and low filling pressures, avoid reducing systolic blood pressure below 90 mmHg. 2. Use with caution in patients with aortic and/or mitral stenosis, orthostatic hypotension, and renal insufficiency.
[Pharmacology and Toxicology]
Isosorbide mononitrate (ISMN) is the primary bioactive metabolite of isosorbide dinitrate. Like other organic nitrates, its primary pharmacological action is to relax vascular smooth muscle. ISMN releases nitric oxide (NO), which, like endothelial relaxing factor, activates guanylate cyclase, increasing cyclic guanosine monophosphate (cGMP) in smooth muscle cells. This relaxes vascular smooth muscle, dilating peripheral arteries and veins and enhancing venous dilation. Venous dilation causes blood to remain in the periphery, reducing venous return and lowering left ventricular end-diastolic pressure and pulmonary capillary wedge pressure (preload). Arterial dilation reduces peripheral vascular resistance, systolic arterial pressure, and mean arterial pressure (afterload). Coronary artery dilation increases coronary perfusion. The overall effect is to reduce myocardial oxygen consumption, increase oxygen delivery, and alleviate angina pectoris. No carcinogenic or mutagenic effects have been observed in animal studies.
