Phenylephrine-SZ, eye drops 2.5% 5 ml

Phenylephrine is an alpha-adrenomimetic with pronounced non-selective alpha-adrenomimetic action. When used in therapeutic doses it does not have significant stimulating effects on the central nervous system.

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

It has little effect on beta-adrenoreceptors, including those in the heart (no positive chrono- and inotropic action). 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 longer lasting. Causes vasoconstriction 30-90 seconds after instillation, duration 2-6 hours.

Phenylephrine instillation is followed by contraction of the dilator of the pupil, resulting in mydriasis, and contraction of the smooth muscles of the conjunctival arterioles. Mydriasis occurs within 10-60 minutes after a single instillation, persists for 2 hours, and is not accompanied by cycloplegia.

Phenylephrine easily penetrates into the eye tissues and reaches its maximum concentration in plasma 10-20 minutes after instillation into the eye. Prior instillation of local anesthetics may increase systemic absorption of phenylephrine and prolong mydriasis.

Phenylephrine is excreted by the kidneys unchanged (< 20%) or as inactive metabolites.

Indications

Iridocyclitis (to prevent posterior synechiae and reduce exudation from the iris).

For diagnostic pupil dilation during ophthalmoscopy and other diagnostic procedures necessary to monitor the condition of the posterior segment of the eye.

The provocation test in patients with a narrow anterior chamber angle profile and suspected closed angle glaucoma.

The differential diagnosis of superficial and deep eyeball injection.

The “red eye” syndrome (to reduce hyperemia and irritation of the mucous membrane of the eye).

Accommodation spasm.

Active ingredient

Composition

1 ml of the drug contains:

the active ingredient:

phenylephrine hydrochloride – 25 mg;

excipients:

sodium edetate dihydrate – 1.0 mg,

citric acid – 1.0 mg,

sodium citrate dihydrate – 5.0 mg,

benzalkonium chloride – 0.1 mg,

How to take, the dosage

For topical use.

In iridocyclitis the drug is used to prevent development and rupture of already formed posterior synechias; to reduce exudation into the anterior chamber of the eye. For this purpose, 1 drop of the drug is instilled into the conjunctival sac of the affected eye (eye) 2-3 times a day.

In ophthalmoscopy, a single instillation of the drug is used. As a rule, instillation of 1 drop of the drug into the conjunctival sac is sufficient to create mydriasis. Maximum mydriasis is achieved in 15-30 minutes and lasts for 1-3 hours.

If necessary to maintain mydriasis for a long time another instillation of the drug after 1 hour is possible.

A single instillation of the drug is used for diagnostic procedures:

– as a provocative test in patients with a narrow anterior chamber angle profile and suspected closed-angle glaucoma. If the difference between the intraocular pressure values before injecting and after pupil dilation is between 3 and 5 mmHg,

For differential diagnosis of the type of ocular injection: if a narrowing of the globe vessels is noted 5 minutes after instillation, the injection is classified as superficial, and if redness remains, the patient must be closely monitored for iridocyclitis or scleritis, as this would indicate dilatation of the deeper vessels.

To relieve spasm of accommodation in children from 6 years of age and adults, the drug is instilled 1 drop in each eye at night daily for 4 weeks.

Interaction

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

The use of phenylephrine with monoamine oxidase inhibitors, and for 21 days after stopping their use, should be used with caution, because in this case there is a possibility of uncontrolled rise in blood pressure.

The vasopressor effect of alpha-adrenomimetics may also be potentiated when used concomitantly with tricyclic antidepressants, propranolol, reserpine, guanethidine, methyldopa, and m-cholinoblockers.

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

The use of phenylephrine with monoamine oxidase inhibitors, and for 21 days after stopping their use, should be used with caution, because in this case there is a possibility of uncontrolled rise in blood pressure.

The vasopressor effect of alpha-adrenomimetics may also be potentiated when used concomitantly with tricyclic antidepressants, propranolol, reserpine, guanethidine, methyldopa and m-cholinoblockers.

Special Instructions

Exceeding the recommended dose of 2.5% solution in patients with trauma, diseases of the eye or its appendages, in the postoperative period or with reduced tear production (anesthesia) may lead to increased absorption of phenylephrine and development of systemic side effects.

The preservative benzalkonium chloride contained in the drug may cause ulcerative toxic keratopathy with prolonged use, especially in patients with concomitant corneal diseases and “dry” eye syndrome. Caution should be exercised when using the drug in this group of patients and corneal condition should be monitored when such patients frequently use the drug. Benzalkonium chloride may discolor soft contact lenses and irritate the eye mucosa. Contact lenses should be removed before instillation of the drug and inserted again not earlier than 15 minutes after instillation.

Impact on driving, operating machinery

When the drug is used due to changes in accommodation and pupil width visual acuity may decrease, therefore, until its recovery it is not recommended to drive vehicles and engage in potentially dangerous activities requiring increased concentration and quick psychomotor reactions.

Synopsis

Contraindications

Hypersensitivity to the components of the drug.

Narrow-angle or closed-angle glaucoma.

Elderly age.

Severe cardiovascular or cerebrovascular disease.

Hypertension in combination with coronary heart disease, aortic aneurysm, atrioventricular block of degree I-III, arrhythmia.

Tachycardia.

Tear production disorder.

Prematurity; childhood under 6 years of age (with accommodation spasm).

Hyperthyroidism.

Hepatic porphyria.

Congenital deficiency of glucose-6-phosphate dehydrogenase.

Rinitis.

With caution

Diabetes mellitus (risk of increased blood pressure associated with autonomic dysregulation).

Concomitant use with monoamine oxidase inhibitors (including for 21 days after stopping their use).

Sickle cell anemia, contact lens wear, after surgical interventions (decreased healing due to conjunctival hypoxia).

Side effects

Eye disorders

Conjunctivitis, periorbital edema.

In some cases patients report a burning sensation at the beginning of use, blurred vision, irritation, discomfort in the eye, lacrimation, increased intraocular pressure.

Phenylephrine may cause reactive miosis the day after use. Repeated instillations of the drug within a short period of time may result in less severe mydriasis than previously observed. This effect is more common in elderly patients.

Phenylephrine-induced significant contraction of the pupil dilation muscle may cause pigment particles from the iris pigment sheet to be seen in the anterior chamber humor 30-45 minutes after instillation. Suspension in the chamber humor must be differentiated from manifestations of anterior uveitis, or from blood cells in the anterior chamber humor.

Systemic reactions

Skin and its appendages: contact dermatitis.

Cardiovascular system: palpitations, tachycardia, arrhythmia, increased blood pressure, ventricular arrhythmia, reflex bradycardia, coronary artery occlusion, pulmonary embolism.

Overdose

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

Treatment: if systemic action of phenylephrine occurs, the adverse effects may be controlled by administration of alpha-adrenoblockers, e.g., 5-10 mg of phentolamine intravenously. If necessary, the injection may be repeated.

Pregnancy use

The effects of phenylephrine in pregnant women have not been adequately studied, so the use of the drug in pregnancy is possible if the potential benefit to the mother outweighs the possible risk to the fetus.

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

It is not known whether the drug is excreted with breast milk. If the drug is prescribed, breastfeeding should be discontinued during treatment.

Similarities