Properties
What is it?
General Characteristics: International and Chemical Names: Phenylephrine; 1-(meta-oxyphenil)-2-methylaminoethanol hydrochloride; Main Physical-Chemical Properties: Clear colorless liquid; Composition: Phenylephrine hydrochloride – 0.01 g; Excipients: Heparin, water for injection. Dosage Form. Solution for injection. Pharmacotherapeutic Group. Adrenergic and dopaminergic preparations. Pharmacological Properties. Mezaton belongs to the group of adrenomimetic substances – stimulators of α-adrenoreceptors. It has a negligible effect on cardiac β-adrenoreceptors. It constricts arterioles and increases arterial pressure, practically not affecting the systolic volume of the heart. It causes pupillary dilation (less prolonged than atropine and without affecting accommodation), and in open-angle glaucoma, it can reduce intraocular pressure. It is more resistant to the action of catechol-o-methyltransferase than catecholamines, which explains the duration of its effects. It is well absorbed both orally and parenterally. Pharmacokinetics. The preparation quickly penetrates the body's tissues, is metabolized under the influence of MAO, and is excreted mainly with urine. When administered intravenously, the effect lasts for 20 minutes, and when administered subcutaneously – for 40-50 minutes. Indications for Use. Mezaton is prescribed to increase arterial pressure in cases of collapse and hypotension that develop as a result of reduced vascular tone, during preparation for and during surgery, in hypotonic disease, to reduce inflammation of the nasal mucosa in vasoconstriction and vasomotor rhinitis, as a substitute for adrenaline in solutions of local anesthetics, in intoxications, infectious diseases, and for pupillary dilation. Method of Administration and Dosage. Mezaton is administered intravenously, subcutaneously, intramuscularly, and as eye drops/solution. In cases of acute drop in arterial pressure, the preparation is usually administered intravenously in doses of 0.1-0.3-0.5 ml of 1% solution in 20 ml of 5-20% glucose solution or in the same volume of isotonic sodium chloride solution. Administration is carried out slowly, and if necessary, it is repeated. For intravenous infusion, 1 ml of 1% Mezaton solution is administered in 250-500 ml of 5% glucose solution. For subcutaneous and intramuscular administration in adults, doses of 0.3-1 ml of 1% solution are used. For pupillary dilation, 2-3 drops of a 1-2% solution of the preparation are instilled into the conjunctival sac. To reduce vasoconstriction and inflammation of the nasal mucosa, a 0.25-0.5% solution is instilled or applied to the mucous membranes. 0.3-0.5 ml of Mezaton solution is added to local anesthetics (per 10 ml of anesthetic solution). Maximum doses for adults: intravenously – single 0.005 g, daily 0.025 g. Subcutaneously and intramuscularly – single 0.01 g, daily 0.05 g. Side Effects. Hypertension, palpitations, ventricular fibrillation, dyspeptic symptoms, cerebral hemorrhage, dizziness, feeling of fear, anxiety, weakness, headache, paleness of facial skin, tremor, convulsions may develop, especially with overdose. With local ophthalmological use – eye pain, headache, conjunctival hyperemia, allergic reaction of the eyelids. Contraindications. Arterial hypertension, atherosclerosis, predisposition to vascular spasms, unstable angina, diabetes mellitus, pregnancy. Interaction with Other Medicinal Products. The vasoconstrictive effect of Mezaton is weakened when used with aminazine and other phenothiazine derivatives. When used with furazolidone, it can cause a hypertensive crisis due to rapid release of noradrenaline. Overdose. Amplification of the drug's side effects, increased arterial pressure, dizziness are possible. Special Precautions for Use. Administer with caution in elderly patients, during anesthesia, in ischemic heart disease, hyperthyroidism, and renal impairment. During pregnancy and lactation, Mezaton is used only under strict indications and medical supervision. Storage Conditions and Shelf Life. Store in a place inaccessible to children, protected from light. Shelf life – 3 years. Dispensing Conditions. By prescription. Packaging. 1 ml in ampoules, 10 ampoules in a box. Manufacturer. LLC "Experimental Plant "SCCC" Branch. Address. Ukraine, Kharkiv, Vorobiov St., 8.
