Phez

Phenylephrine HCl.

Each mL contains Phenylephrine 100 mg.

Pharmacology: Pharmacodynamics: Phenylephrine hydrochloride is a synthetic sympathomimetic amine. After topical application to the conjunctiva, phenylephrine acts directly on α-adrenergic receptors in the eye producing contraction of the dilator muscle of the pupil and constriction of arterioles in the conjunctiva. Phenylephrine hydrochloride is used for local ocular disorders because of its vasoconstrictor and mydriatic action. There is almost no cycloplegic effect.
Pharmacokinetics: Phenylephrine is a weak base at physiological pH. The extent of ocular penetration is determined by the condition of the cornea. A healthy cornea presents a physical barrier, in addition to which, some metabolic activity may occur. Where the corneal epithelium is damaged, the effect of the barrier and the extent of metabolism are reduced, leading to greater absorption.
Administration of a 10% solution of Phenylephrine hydrochloride produces maximal mydriasis within 10-90 minutes; recovery occurs within 3-7 hours.
Occasionally, enough Phenylephrine may be absorbed following topical application to the conjunctiva to cause systemic sympathomimetic effects. Circulating drug is metabolized in the liver by the enzyme monoamine oxidase (MAO).

Phenylephrine is used topically in the eye as a mydriatic and a vasoconstriction. Phenylephrine may be used for diagnostic or therapeutic procedures.

Adults: Mydriasis: Instill 1 drop topically to each eye. If necessary, the dose may be repeated after 1 hour (As directed by the physician).
Pediatric: Mydriasis: Instill 1 drop topically to each eye. If necessary, the dose may be repeated after 1 hour. (As directed by the physician)
It is not usually necessary to exceed this dose.
Heavily pigmented irides may require larger doses and caution should be exercised to avoid overdosage.
The use in preterm and newborn infants is not recommended unless clearly necessary and only with caution because of safety concerns associated with the risk of systemic adverse reactions including transient increases in blood pressure. If treatment is medically justified, the lowest possible concentration and dose should be used and instillation of more than one drop per eye must be avoided.
Administration: The use of a drop of topical anaesthetic a few minutes before instillation of Phenylephrine is recommended to prevent stinging. Butacaine sulfate should not be used because it is incompatible with Phenylephrine.
Especially in infants, children and the elderly, it is advised to minimise systemic absorption and the risk for systemic adverse reactions by compressing the lacrimal sac at the medial canthus or gently closing the eye for a few minutes after instillation. To minimise cutaneous absorption, excess fluid should be wiped away from the periocular area.
Wash hands before and after application.
For topical ophthalmic use only.
To avoid contamination, do not touch dropper tip to eyelids or other surfaces when placing drops in eyes.
Solution should be applied to the conjunctival fornix unless otherwise directed.
Protect eyes from bright illumination while pupils are dilated.

Phenylephrine-induced hypertension may be relieved by administration of an α-adrenergic blocking agent (e.g. phentolamine).

Phenylephrine hydrochloride ophthalmic solution is contraindicated in person with a known hypersensitivity to Phenylephrine products or any of its components.
Phenylephrine hydrochloride ophthalmic solution should be avoid in patients with preexisting cardiovascular disease or cerebrovascular disease.
Phenylephrine hydrochloride ophthalmic solution is contraindicated in patients with angle-closure glaucoma.
Phenylephrine hydrochloride 10% ophthalmic solution is contraindicated for use in infants younger than 1 year.

The cardiovascular status of the patient should be considered before Phenylephrine is administered.
The drug should be used with caution in patients with marked hypertension, cardiac disorders, advanced arteriosclerotic changes, type 1 (insulin-dependent, IDDM) diabetes mellitus or hyperthyroidism. Blood pressure should be carefully monitored if the Phenylephrine hydrochloride 10% is used in these patients or in other patients who develop symptoms.
Phenylephrine should be administered with caution to patients at increased risk of adverse systemic effects of the drug.
Increased risk of vasopressor response with higher than recommended doses, or with application to instrumented (e.g. tonometry), traumatized, diseased, or postsurgical eye or adnexa, or with reduced lacrimation during anesthesia.
Rebound miosis is reported in older patients within one day; caution is advised to monitor for this effect in patients undergoing retinal detachment or cataract surgery.
Phenylephrine ophthalmic solutions should not be used in patients with soft contact lenses.
Risk of precipitating severe hypertension.
Do not use Phenylephrine hydrochloride solution if brown or contains a precipitate.

Pregnancy: Pregnancy category C.
Animal reproduction studies have not been performed with Phenylephrine. It is not known whether topically applied Phenylephrine can cause fetal harm when administered to pregnant women. Parenterally administered Phenylephrine in late pregnancy or labor may cause fetal anoxia. Topically applied Phenylephrine should be used during pregnancy only when clearly needed.
Lactation: Since it is not known whether Phenylephrine is distributed into milk, the drug should be used with caution in nursing women.

Undesirable effects from the use of Phenylephrine ophthalmic solution may occur.
Ophthalmic: eye pain, burning or stinging, blurred vision, transient keratitis allergic conjunctivitis, photophobia, lower IOP in normal eyes (tonometry), rebound miosis.
Cardiovascular: reactive hyperemia, palpitation, tachycardia, premature ventricular contractions, hypertension.
Central nervous system: headache or browache, occipital headache, tremors.
Dermatologic: dermatitis, pallor.
Respiratory: pulmonary edema.
Immunologic: hypersensitivity reactions, allergic reactions and anaphylaxis (from preservatives).

Concomitant administration of Phenylephrine with cycloplegic antimuscarinic drugs such as atropine sulfate, cyclopentolate hydrochloride, homatropine hydrobromide, or scopolamine hydrobromide produces increased dilation of the pupil which is of clinical value.
Phenylephrine must be administered under careful supervision and in reduced dosage if used within 21 days after the patient has received a monoamine oxidase inhibitor (MAOI) because potentiation of the pressor effects of phenylephrine may result. There is an increased risk of hypertension when used concurrently with the administration of MAOIs.
The pressor response to Phenylephrine may be potentiated if a tricyclic antidepressant is administered concomitantly. The risk of raised blood pressure and cardiac arrhythmia may also be potentiated.
If Phenylephrine is administered to a patient undergoing chronic oral therapy with guanethidine, the pupillary response to Phenylephrine is greatly increased and the pressor response may also be potentiated. There is an increased risk of hypertension when used concurrently with the administration of guanethidine. Phenylephrine should be administered cautiously to patients receiving guanethidine.
The mydriatic response to Phenylephrine is decreased in patients receiving levodopa.
Because of the increased risk of cardiovascular effects, Phenylephrine should be used with caution during general anaesthesia with anaesthetic agents.

Keep in refrigerator or at temperature 2-8°C (No freezing) and protect from light.

Mydriatic Drugs

S01FB01 - phenylephrine ; Belongs to the class of sympathomimetics used as mydriatics and cycloplegics.

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