Description
Nitrosorbide Pharmacodynamics
Peripheral vasodilator with a predominant effect on the venous vessels. Antianginal agent. The mechanism of action is related to the release of the active substance nitric oxide in the smooth muscle of the vessels. Nitric oxide causes activation of guanylate cyclase and increases the level of cGMP, which ultimately leads to relaxation of smooth muscles. Under the influence of isosorbide dinitrate, arterioles and precapillary sphincters relax less than large arteries and veins. This is partly due to reflex reactions, as well as less intense formation of nitric oxide from the active substance molecules in the walls of the arterioles.
The action of isosorbide dinitrate is mainly due to the reduction of myocardial oxygen demand by reducing preload (dilation of peripheral veins and reduction of blood flow to the right atrium) and postload (reduction of PPS), as well as a direct coronary dilatatory effect. It promotes redistribution of coronary blood flow in the area with reduced blood supply.
Increases exercise tolerance in patients with coronary heart disease, angina pectoris. In heart failure helps unload myocardium by reducing the preload. Reduces pressure in the small circle of the circulation.
Indications
Prevention and treatment of angina attacks, rehabilitation after myocardial infarction (in combination therapy), chronic heart failure (in combination therapy).
Contraindications .
Hypersensitivity to organic nitrates, hemorrhagic stroke, severe arterial hypotension (systolic BP less than 100 mm Hg, diastolic BP less than 60 mm Hg), collapse, shock, acute myocardial infarction with significant arterial hypotension, increased intracranial pressure, toxic pulmonary edema, closed-angle glaucoma with high intraocular pressure, craniocerebral trauma, age under 18 years (effectiveness and safety have not been established).
With caution: Hypertrophic cardiomyopathy (increased frequency of angina attacks is possible), constrictive pericarditis, cardiac tamponade; aortic and/or mitral stenosis, severe hepatic insufficiency (risk of methemoglobinemia), severe renal failure, cerebral hemorrhage, acute myocardial infarction (risk of decreased blood pressure and tachycardia, which may worsen ischemia), severe anemia, hyperthyroidism, patients with a tendency to orthostatic hypotension, elderly patients, increased peristalsis of the gastrointestinal tract, malabsorption syndrome.
Administration during pregnancy and lactation
It should be used only after careful weighing of the benefit-risk ratio associated with the use of the drug, because the experience of using in pregnant and lactating women is insufficient. Fetal category of action C.
Directions for use and dosages
- The drug is administered orally or sublingually.
- For prevention of angina attacks, the initial oral dose is 10 mg 4-5 times a day. If efficacy is insufficient, from the 3-5th day of treatment, the drug dose may be increased to 60-120 mg per day.
- To stop an attack of angina pectoris, 1 tablet (10 mg) of Nitrosorbide is taken sublingually (to speed up its action, the tablet should be chewed).
- In combined therapy of chronic heart failure 10-20 mg 3-4 times a day is prescribed.
- The duration of treatment is determined in each case individually. If necessary, the drug is withdrawn gradually.
