Nitroglycerin, 0.5 mg capsules 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.

It has a central inhibitory effect on the sympathetic vascular tone, suppressing 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 plasma proteins. It is highly lipophilic and has a large 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.

The total clearance is 30-78 l/min, 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

Unstable angina, pulmonary edema, acute myocardial infarction (including one complicated by acute left ventricular failure); relief of angina attacks.

Active ingredient

Composition

Active ingredient:

Nitroglycerin 0.5 mg;

How to take, the dosage

Sublingual.

Nitroglycerin is recommended to be taken by prescription.

The tablet (capsule) is held under the tongue until completely absorbed, 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

Prescribing with dihydroergotamine may lead to an increase in its blood content and lead to an increase in 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 reducing the dose of heparin).

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

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

Severe anemia; hyperthyroidism; age less than 18 years (safety of use not established); hypersensitivity to nitrates; cranial 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; recent head trauma; toxic pulmonary edema; idiopathic hypertrophic subaortic stenosis; closed angle glaucoma with high intraocular pressure; cerebral circulation disorders; shock; arterial hypotension (CAD simultaneous use of sildenafil (Viagra); pregnancy; breastfeeding period. With caution (comparing risk and benefit): severe renal failure; hepatic failure (risk of methemoglobinemia).

Side effects

Allergic reactions: rare – skin rash, itching. Local reactions: skin hyperemia, skin itching, burning, allergic contact dermatitis.

Cardiovascular system disorders: dizziness, “nitrate” headache, tachycardia, skin hyperemia, fever, palpitations, decreased blood pressure, 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.

Other: blurred vision, weakness, hypothermia, methemoglobinemia.

Overdose

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

Treatment: discontinue further administration. The head of the bed should be lowered and the patient’s legs should be elevated.

In this case, BP usually normalizes within 15-20 min after stopping the nitroglycerin infusion, then the infusion can be continued, after adjusting the infusion rate again.

Similarities