Irifrin BK, eye drops 2.5% 0.4 ml 15 pcs

Irifrin BC has alpha-adrenomimetic action.

Pharmacodynamics

Phenylephrine is an adrenomimetic. It has pronounced alpha-adrenergic activity and has no significant stimulating effect on the CNS when used in normal doses.

When used topically in ophthalmology, it causes dilation of the pupil, improves the outflow of intraocular fluid and narrows the conjunctival vessels.

Phenylephrine has a strong stimulatory effect on the postsynaptic alpha-adrenoreceptors, it has very little effect on the beta-adrenoreceptors of the heart, it has almost no positive chronotropic and inotropic effect on the heart. The drug has a vasoconstrictor effect similar to that of norepinephrine (noradrenaline). The vasopressor effect of phenylephrine is weaker than that of norepinephrine, but it is more durable. It causes vasoconstriction 30-90 s after instillation, the duration is 2-6 h.

Phenylephrine contracts the dilator of the pupil after instillation, thereby causing dilation of the pupil and smooth muscles of the conjunctival arterioles. Midriasis occurs within 10-60 min after a single injection; it lasts for 2 h after 2.5% solution; 3-6 h after 10% solution. Midriasis caused by phenylephrine is not accompanied by cycloplegia.

Pharmacokinetics

Phenylephrine easily penetrates into the eye tissues, Cmax in plasma occurs 10-20 min after local administration. Prior instillation of local anesthetics may increase systemic absorption and prolong mydriasis. Phenylephrine is excreted unchanged in the urine.

Indications

Active ingredient

Composition

Active ingredient:

Phenylephrine hydrochloride 25 mg;

Associates:

dinatrium edetate 1.0 mg,

sodium metabisulfite 2.0 mg,

citric acid 1.16 mg,

sodium citrate dihydrate.э.,

hyprmellose 3.0 mg,

water for injection q.s.

How to take, the dosage

Conjunctival. Single instillations of 2.5% Irifrin® BC solution are used during ophthalmoscopy. As a rule, 1 drop of 2.5% Irifrin® BC solution in the conjunctival sac is sufficient to create mydriasis.

The maximum mydriasis is achieved in 15-30 min and maintained at a sufficient level for 1-3 h. If it is necessary to maintain mydriasis for a long time after 1 h it is possible to repeat instillation of Irifrin® BC.

In diagnostic procedures:

– As a provocative test in patients with a narrow anterior chamber angle profile and suspected closed-angle glaucoma, 1 drop of the drug is injected once. If the difference between the intraocular pressure before Irifrin® BC and after pupil dilation is between 3 and 5 mmHg,

The provocative test is considered positive;

For differential diagnosis of the type of eyeball injection, 1 drop of the drug is injected once; if vasoconstriction of the eyeball is noted 5 min after injection, the injection is classified as superficial; if redness of the eye persists, the patient must be carefully examined for iridocyclitis or scleritis, as this indicates dilation of the deeper underlying blood vessels.

In case of iridocyclitis to prevent development and rupture of already formed posterior synechias and decrease exudation into the anterior chamber of the eye – 1 drop of the drug is dropped into the conjunctival sac of the affected eye 2-3 times a day for 5-10 days depending on the disease severity.

In pupils with low myopia for prophylaxis of accommodation spasm in case of high visual load – 1 drop of Irifrin® BC instilled in the evening before bedtime; with medium degree progressive myopia – 3 times a week in the evening before bedtime; with emmetropia – during the day depending on the load.

In hyperopia with a tendency to accommodation spasm at high visual load – Irifrin® BC is injected in the evening in combination with 1% cyclopentolate solution. In case of normal visual load Irifrin® BC is injected 3 times a week in the evening before going to bed.

In the treatment of false and true myopia, 1 drop of Irifrin® BK is injected in the evening before bedtime 2-3 times a week for one month.

Interaction

The mydriatic effect of phenylephrine is enhanced when it is used in combination with topical administration of atropine. Due to the increased vasopressor effect, tachycardia may develop.

The use of Iriphrine BC within 21 days after discontinuation of monoamine oxidase inhibitors and tricyclic antidepressants in patients should be used with caution, as there is a possibility of uncontrolled rise in blood pressure.

The vasopressor effect of adrenergic agents may also be potentiated when combined with tricyclic antidepressants, beta-adrenoblockers, reserpine, guanethidine, methyldopa and m-cholinoblockers.

Irifine BC may potentiate cardiovascular depression during inhalation anesthesia by increasing myocardial sensitivity to sympathomimetics and causing ventricular fibrillation.

The use in combination with other sympathomimetics may increase the cardiovascular effects of phenylephrine.

Phenylephrine use may cause impairment of concomitant hypotensive therapy and lead to increased blood pressure and tachycardia.

Preinjection of local anesthetics may increase systemic absorption and prolong Midriasis

Contraindications

Side effects

Topical

Conjunctivitis, periorbital edema. In some cases patients report a burning sensation (at the beginning of use), blurred vision, irritation, discomfort, lacrimation, increased intraocular pressure.

Phenylephrine can cause reactive miosis the day after administration; at this time, repeated instillations of the drug may produce less mydriasis than the day before; the effect is more common in older patients.

Within 30-45 min after instillation, particles of pigment from the pigmentary sheet of the iris may be detected in the moisture of the anterior chamber of the eye due to significant contraction of the pupil dilator under the influence of phenylephrine. Suspension in the chamber humor should be differentiated with manifestations of anterior uveitis or admittance of blood cells into the humor of the anterior chamber.

Systemic: contact dermatitis.

Systemic: palpitations, tachycardia, cardiac arrhythmia, increased BP, ventricular arrhythmia, reflex bradycardia, coronary artery occlusion, pulmonary embolism.

In rare cases after topical use of 10% phenylephrine solution, development of myocardial infarction, vascular collapse and intracranial hemorrhage is possible.

Overdose

Symptoms: overdose are restlessness, nervousness, dizziness, sweating, vomiting, palpitations, weak or shallow breathing.

Treatment: if phenylephrine is systemic, the adverse events can be managed by the use of alpha-adreno-blockers, such as 5 to 10 mg of phentholamine intravenously.

The injection may be repeated if necessary.

Pregnancy use

Pregnancy

In animals in late pregnancy, phenylephrine caused fetal growth retardation and stimulated early onset of labor.

The effects of Iririn BC in pregnant women have not been well studied, so the drug should only be used in this category of patients if the expected benefit to the mother outweighs the risk of possible side effects to the fetus.

Lactation

Breast-feeding should be stopped if the drug is prescribed during lactation.

Similarities