Description
Nitrospray Pharmacodynamics
Nitroglycerin is an organic nitrogen-containing compound with a predominant venodilator effect.
The effects of nitroglycerin are due to its ability to release from its molecule nitric oxide, which is a natural endothelial relaxing factor. Nitric oxide increases the intracellular concentration of cyclic guanosine monophosphatase, which prevents the penetration of calcium ions into the smooth muscle cells and causes them to relax. The relaxation of the smooth muscles of the vascular wall causes vasodilation, which reduces the venous return to the heart (preload) and the resistance of the great circle of circulation (postload). This reduces heart function and myocardial oxygen demand. Dilation of the coronary vessels improves coronary blood flow and promotes its redistribution to areas with decreased blood flow, which increases oxygen delivery to the myocardium.
Decrease of venous return leads to decrease of filling pressure, improvement of subendocardial blood supply, decrease of pressure in the small circle of circulation and regression of symptoms in pulmonary edema. Nitroglycerin has central inhibitory effect on sympathetic vascular tone, depressing vascular component of pain syndrome formation. Nitroglycerin relaxes smooth muscle cells of bronchi, urinary tract, gall bladder, bile ducts, esophagus, small and large intestine. The action begins quickly, the effect develops within 1-1.5 minutes and lasts about 30 minutes.
Indications
– Prevention of angina attacks by preventive therapy before physical load or emotional stress;
– control of angina episodes.
Contraindications
– Hypersensitivity to the active substance, other organic nitrates or excipients;
– Acute vascular insufficiency (shock collapse);
– Under 18 years of age (efficacy and safety have not been established);
– concomitant use of phosphodiesterase-5 inhibitors (including sildenafil, vardenafil, tadalafil, udenafil), because they potentiate the antihypertensive effects of nitrates;
– constrictive pericarditis;
– cardiac tamponade;
– Arterial hypotension with systolic pressure less than 90 mm Hg (may aggravate the condition by causing paradoxical bradycardia and angina attacks)
– hypertrophic obstructive cardiomyopathy (may increase angina attacks);
– severe anemia;
– Severe aortic/subaortic stenosis or mitral stenosis;
– severe hypovolemia;
– head injuries;
– conditions with increased intracranial pressure (e.g., cerebral hemorrhage;
increased intracranial pressure has been noted with high doses of nitroglycerin);
– concomitant use with soluble guanylate cyclase stimulators (riociguat).
How to use and dosages
- The spray is sprayed sublingually. One spray is 1 dose (0.4 mg).
- The drug is recommended to be taken as prescribed by a physician in order to avoid complications.
- Treatment of an attack of angina pectoris.
- For the first angina attack, apply 1 or 2 doses under the tongue. If necessary, it may be administered repeatedly at 5-minute intervals. If after taking three doses within 15 minutes the attack does not stop, you should immediately consult a physician.
- Before coronarography: in order to prevent spasm of coronary vessels, 1-2 sprays (0.4-0.8 mg) are recommended.
- For preventive purposes, 1 dose 5-10 minutes before anticipated exertion or stress.
- Maximum single dose: 4 doses. Maximum daily dose: 16 doses.
- Instructions for taking the drug:
– If possible, sit down;
– Remove the protective cap from the bottle; hold the bottle vertically;
– Open your mouth and hold your breath for a few seconds;
– press once on the nozzle of the vial, directing the stream of the drug under your tongue;
– Close your mouth and try not to swallow the drug. - When using for the first time or after prolonged non-use, it is recommended that one dose be dropped into the air to fill the aerosol chamber before direct use.
