Phenylephine hydrochloride

Phenylephine hydrochloride – medicine with vasopressor and alpha адреномиметическим action.

Form of release and structure

The phenylephine hydrochloride is issued in the form of solution for injections: transparent, colourless (on 1 ml in ampoules, in a pack of cardboard 10 ampoules complete with the ceramic cutting disk or the ampoule scarificator).

Active ingredient: Phenylephrinum a hydrochloride, in 1 ml – 10 mg.

Auxiliary components: injection water and glycerin.

Indications to use

• Vascular insufficiency (including owing to overdose of vazodilatator);
• Arterial hypotension;
• Allergic and vasculomotor rhinitis;
• Depressed cases, including toxic and traumatic shock.

Besides, the Phenylephine hydrochloride is applied when carrying out local anesthesia as vasopressor means.

Contraindications

Absolute:

• Hypertrophic subaortic stenosis;
• Fibrillation of ventricles;
• Pheochromocytoma;
• Hypersensitivity to drug.

Relative (it is necessary to observe extra care in connection with risk of development of complications):

• Arterial hypertension, hypertensia in a small circle of blood circulation, fibrillation of auricles, ventricular arrhythmia, an acute myocardial infarction, a heavy stenosis of the mouth of an aorta, closed-angle glaucoma, a hypoxia, a hypovolemia, a hypercapnia, a tachyarrhythmia, a metabolic acidosis;
• Occlusal diseases of vessels (including in the anamnesis): a Thrombangiitis obliterans (an obliterating thromboangitis), atherosclerosis, a Raynaud's disease, an arterial thromboembolism, tendency of vessels to spasms (including at freezing injury), a porphyria, a diabetes mellitus, deficit glyukozo-6-fosfatdegidrogenazy, a thyrotoxicosis, a diabetic endarteritis;
• Simultaneous use of monoamine oxidase inhibitors (MAO);
• Functional disturbances of kidneys;
• General ftorotanovy anesthesia;
• Age up to 18 years;
• Advanced age.

To pregnant women and the nursing women the Phenylephine hydrochloride can be appointed only according to strict indications, after assessment of a ratio of advantage and possible risks.

Route of administration and dosage

Solution the Phenylephine hydrochloride is entered intravenously (struyno or kapelno), intramusculary or subcutaneously.

At a collapse enter intravenously slowly struyno in a dose 0,1-0,3-0,5 ml, previously having parted 20 ml of 0,9% of solution of sodium of chloride or 5% of solution of a dextrose. If necessary enter one more dose.

Kapelno intravenously the drug is administered in a dose 1 ml, previously having parted 250-500 ml of 5% of solution of a dextrose.

Intramusculary or subcutaneously the Phenylephine hydrochloride is appointed by the adult in a dose of 0,3-1 ml by 2-3 times a day, to children 15 years at arterial hypotension are more senior during spinal anesthesia – in a dose of 0,5-1 mg on each kilogram of body weight.

For reduction of the inflammatory phenomena and vasoconstriction of mucous membranes drug (in concentration – 0,125, 0,25, 0,5, 1%) is used for greasings or instillations.

When carrying out local anesthesia on each 10 ml of solution of anesthetic add 1% of solution of the Phenylephine hydrochloride on 0,3-0,5 ml.

The most admissible doses for adults:

• Intravenously: one-time – 5 mg, daily – 25 mg;
• Intramusculary and subcutaneously: one-time – 10 mg, daily – 50 mg.

Side effects

• Cardiovascular system: increase in arterial pressure, tachycardia, arrhythmia, fibrillation of ventricles, cardialgia, bradycardia;
• Central nervous system: sleeplessness, sensation of fear, concern, dizziness, weakness, paresthesias, tremor, spasms, headache, hematencephalon;
• Others: skin ischemia in the place of an injection, pallor of face skin; in isolated cases – allergic reactions, an escharosis and a necrosis (at subcutaneous injections and in case of hit of solution in fabric).

Special instructions

During treatment control of indicators of the electrocardiogram, arterial pressure, blood circulation in the place of an injection and extremities, the minute volume of blood is necessary.

Before the beginning or during treatment of depressed cases correction of a hypoxia, a hypovolemia, hypercapnia and acidosis is required.

In case of a medicamentous collapse patients with arterial hypertension have enough to support systolic arterial pressure at the level below usual on 30-40 mm hg.

Permanent disturbances of a heart rhythm, the expressed tachycardia or bradycardia, sharp increase in arterial pressure demand cancellation of the Phenylephine hydrochloride.

To prevent a repeated lowering of arterial pressure after drug withdrawal, the dose is recommended to be reduced gradually, especially after long infusion. However if systolic arterial pressure decreases to the level of 70-80 mm hg, infusion is resumed.

It must be kept in mind that the vasoconstrictors applied in addition to local anesthetics at the same time with the means stimulating patrimonial activity (ergotamine, vasopressin, methylergometrine, ergometrine), or intended for correction of arterial hypotension at the time of delivery can entail permanent increase in arterial pressure in a puerperal period.

With age the quantity of adrenoceptors, sensitive to Phenylephrinum, decreases. MAO inhibitors, increasing pressor effect of sympathomimetics, can promote emergence of vomiting, development of arrhythmia, headaches, hypertensive crisis. For this reason for patients who in the previous 2-3 weeks accepted MAO inhibitors doses of sympathomimetics should be reduced.

During treatment by the Phenylephine hydrochloride it is necessary to refrain from occupations the types of activity demanding the speed of mental and motor reactions including from driving of motor transport.

Medicinal interaction

Possible reactions of interaction in case of simultaneous use of the Phenylephine hydrochloride and other medicines:

• Anti-hypertensive drugs, diuretics: decrease in their hypotensive effect;
• Monoamine oxidase inhibitors (Procarbazinum, furasolidone, селегилин), tricyclic antidepressants, ergot alkaloids, adrenostimulyator, methylphenidate, oxytocin: strengthening of pressor action and aritmogennost of Phenylephrinum;
• Inhalation anesthetics (halothane, энфлуран, метоксифлуран, изофлуран, chloroform): increase in risk of development of heavy ventricular and atrial arrhythmia;
• Nitrates: reduction of their anti-anginal effect, decrease in pressor effect of Phenylephrinum, risk of development of arterial hypotension;
• Thyroid hormones: a synergism of effect of drugs and strengthening of the risk of development of coronary insufficiency connected with it, especially at patients with coronary atherosclerosis;
• Alpha adrenoblockers, fenotiazina: decrease in hypertensive effect;
• Methylergometrine, to doksapra, ergotamine, oxytocin, ergometrine: strengthening of expressiveness of vasopressor action;
• Beta adrenoblockers: decrease in the cardiostimulating activity; at use of Reserpinum – risk of development of arterial hypertension.

Terms and storage conditions

To store at a temperature to 25ºC. Not to subject to light influence. To protect from children.

Period of validity – 3 years.