Nitroglycerin, 0.5 mg 40 pcs

Nitroglycerin is a venodilator from the group of nitrates. Nitrates are able to release from their molecule nitric oxide, which is a natural endothelial relaxing factor – a mediator of direct guanylate cyclase activation. Increased concentration of cGMP leads to relaxation of smooth muscle fibers, mainly venules and veins. It has antianginal and antispasmodic effects, relaxes the smooth muscle of the vascular walls, bronchi, gastrointestinal tract, biliary tract, ureters. When administered intravenously (IV) it quickly reduces the preload on the heart due to the expansion of peripheral veins.

Decreases blood flow to the right atrium, promotes reduction of pressure in the small circle of circulation and regression of symptoms in pulmonary edema, reduces afterload, myocardial oxygen demand (by reducing the preload, afterload and ventricular wall tension due to decreased heart volume). It promotes redistribution of coronary blood flow in the area with reduced blood flow.
Has a central inhibitory effect on the sympathetic vascular tone, depressing the vascular component of pain syndrome formation. Causes dilation of meningeal vessels, which explains the headache when using it.

Pharmacokinetics

In the systemic bloodstream, 60% is bound by blood plasma proteins. It is highly lipophilic and has high volume of distribution (3.3-1.2 l/kg). It is rapidly metabolized in the liver by glutathione reductase, which affects organic nitrates, with the formation of di- and mononitrates; the final metabolite is glycerol. It is excreted by the kidneys as metabolites. Total clearance is 30-78 l/min, the elimination half-life is 1-3 min. In addition, nitroglycerin is metabolized in erythrocytes by enzymatic reactions involving sulfhydryl radicals and by interaction with reduced hemoglobin.

Indications

Stenocardia, Myocardial infarction, Cardialgia (pain in the heart area)

Acute myocardial infarction (including those complicated by acute left ventricular failure); unstable angina, pulmonary edema, control of angina attacks.

Active ingredient

Nitroglycerin

Composition

Tablets

Active ingredient: nitroglycerin 0.5 mg;

Excipients: crosspovidone CL; lactose; povidone 25; macrogol 6000

How to take, the dosage

Sublingual.

Nitroglycerin is recommended to be taken by prescription.

The tablet (capsule) is held under the tongue until completely consumed, without swallowing, immediately after pain occurs, 0.5-1 mg per dose. Many patients with stable angina pectoris have a smaller dose (1/2-1/3 of a tablet), so if the pain disappears quickly, it is recommended that the remainder of the tablet, which has not had time to dissolve, be spat out. Usually the antianginal effect is seen in 0.5-2 minutes; 75% of patients report improvement within the first 3 minutes, and another 15% – within 4-5 minutes. If there is no antianginal effect, 1 more tablet (capsule) should be taken within the first 5 minutes. nitroglycerin. If there is no therapeutic effect after taking 2-3 tablets (capsules), it is necessary to call a doctor immediately. The duration of action after sublingual administration is about 45 minutes. With frequent attacks of angina it is customary to prescribe prolonged nitroglycerin drugs. Tolerance to sublingual forms of nitroglycerin rarely develops, however if it occurs in some patients, the dose of the drug has to be gradually increased, bringing it to 2-3 tablets (capsules).

Interaction

Simultaneous administration with vasodilators, hypotensive agents, angiotensin-converting enzyme inhibitors (ACE), beta-adrenoblockers, “slow” calcium channel blockers, procainamide, tricyclic antidepressants, monoamine oxidase inhibitors (MAOIs), phosphodiesterase inhibitors, and ethanol, increases the hypotensive effect.

Prescribing with dihydroergotamine may increase its content in blood and lead to increased BP (increased bioavailability of dihydroergotamine).
The simultaneous administration of nitroglycerin and heparin reduces the effectiveness of the latter (after discontinuation of the drug a significant decrease in blood clotting may occur, which may require reduction in the dose of heparin).

Special Instructions

Nitroglycerin may cause a significant decrease in BP and dizziness when suddenly moving to an upright position from a “lying” or “sitting” position, when drinking alcohol, exercising, and when the weather is hot. Nitroglycerin, as with all organic nitrates, is very addictive with frequent use, requiring higher doses.

When driving vehicles and operating mechanisms requiring increased attention, it should be noted that nitroglycerin administration may decrease motor and mental reaction time.

The severity of headache during nitroglycerin administration may be reduced by reducing its dose and/or by concomitant administration of Validol.

Contraindications

• high sensitivity to nitrates;
• cranial and cerebral hypertension;
• cardiac tamponade;
• isolated mitral stenosis;
• constrictive pericarditis (conditions accompanied by decreased left ventricular filling pressure);
• uncontrolled hypovolemia;
• heart failure with normal or low pulmonary artery pressure;
• collapse;
• hemorrhagic stroke;
• subarachnoid hemorrhage;
• toxic pulmonary edema;
• idiopathic hypertrophic subaortic stenosis;
• closed-angle glaucoma with high intraocular pressure;
• severe anemia;
• hyperthyroidism;
• cerebral circulation disorder;
• shock;
• arterial hypotension (BP
• concurrent use of sildenafil (Viagra);
• pregnancy;
• period of breastfeeding.

With caution (comparing risk and benefit): severe renal failure; hepatic failure (risk of methemoglobinemia).

Side effects

Cardiovascular system: dizziness, “nitrate” headache, tachycardia, skin hyperemia, fever, palpitations, decreased BP, rarely (especially in overdose) – orthostatic collapse, cyanosis.

Gastro-intestinal tract: dry mouth, nausea, vomiting, abdominal pain.

As to the central nervous system: rarely (especially in overdose) – anxiety, psychotic reactions, lethargy, disorientation.

Allergic reactions: rarely – skin rash and itching.

Local reactions: skin hyperemia, skin itching, burning, allergic contact dermatitis.

Others: blurred vision, weakness, hypothermia, methemoglobinemia.

Overdose

Symptoms: marked BP decrease (below 90 mmHg) with orthostatic dysregulation, reflex tachycardia, headache, asthenia, dizziness, increased somnolence, fever, nausea, vomiting, with high doses (more than 20 mg/kg) – collapse, cyanosis, methemoglobinemia, dyspnea and tachypnea may develop.

Treatment: discontinue further administration. The head of the bed should be lowered and the patient’s legs should be elevated. As a rule, BP will normalize within 15-20 minutes after stopping the nitroglycerin infusion, and then it is possible to continue the infusion, after adjusting the infusion rate again.

Similarities

Nitroglycerin, Nitrospray-ICN, Nitrocor