Phenylephrine HCl

A to Z Drug Facts

Phenylephrine HCl

	Action
	Indications
	Contraindications
	Route/Dosage
	Interactions
	Lab Test Interferences
	Adverse Reactions
	Precautions
Patient Care Considerations
	Administration/Storage
	Assessment/Interventions
	Patient/Family Education

(fen-ill-EFF-rin HIGH-droe-KLOR-ide)

Ah-chew D, AK-Dilate, AK-Nefrin, Aleconefrin, Alconefrin 12, Alconefrine 25, Children's Nostril, Mydfrin 2.5%, Neo-Synephrine, Nostril, Phenoptic, Prefrin Liquifilm, Relief, Rhinall, Sinex, Dionephrine Prefrin Liquifilm, Diophenyl-T, Novahistine Decongestant, Prefrin Liquifilm

Class: Vasopressor, Decongestant

Action Stimulates postsynaptic alpha-receptors, resulting in rise in intense arterial peripheral vasoconstriction. Causes marked increase in systolic, diastolic and pulmonary pressures as well as reflex bradycardia. Slightly decreases cardiac output and increases coronary blood flow.

Indications Treatment of vascular failure in shock, shocklike states, drug-induced hypotension or hypersensitivity; correction of paroxysmal supraventricular tachycardia; prolongation of spinal anesthesia; vasoconstriction in regional analgesia; maintenance of adequate level of BP during spinal and inhalation anesthesia; temporary relief of nasal congestion and of minor eye irritations; pupil dilation in uveitis; treatment of open-angle glaucoma; use in diagnostic procedures (funduscopy) and before surgery.

Contraindications Severe hypertension; ventricular tachycardia; pheochromocytoma; 10% ophthalmic solution contraindicated in infants and patients with aneurysms.

Route/Dosage

Mild or Moderate Hypotension

ADULTS: SC/IM 1 to 10 mg (usually 2 to 5 mg); do not exceed initial dose of 5 mg. IV 0.1 to 0.5 mg (usually 0.2 mg); do not exceed initial dose of 0.5 mg. Avoid repeat injections more often than q 10 to 15 min.

Severe Hypotension and Shock

ADULTS: IV continuous infusion Initial dose: 100 to 180 mcg/min of 1:25,000 or 1:50,000 solution (10 mg/250 to 500 ml D5W or Sodium Chloride); once BP has stabilized to low normal level, decrease to maintenance rate of 40 to 60 mcg/min. If prompt initial vasopressor response is not obtained, increase dosage in increments ³ 10 mg and add to infusion; adjust rate until desired BP is obtained.

Hypotension of Spinal Anesthesia

ADULTS: SC/IM 2 to 3 mg 3 to 4 min before injection of anesthetic. For hypotensive emergencies during spinal anesthesia, inject 0.2 mg, increasing by no more than 0.1 to 0.2 mg/dose (maximum 0.5 mg/dose). CHILDREN: SC/IM 0.5 to 1 mg/25 lb (55 kg).

Prolongation of Spinal Anesthesia

ADULTS: 2–5 mg added to anesthetic solution increases duration of motor block by up to 50%.

Vasoconstriction for Regional Analgesia

ADULTS: ³ 2 mg added to local anesthetic solution in concentration of 1:20,000 (1 mg/20 ml).

Paroxysmal Supraventricular Tachycardia

ADULTS: IV Initial dose: £ 0.5 mg via rapid IV push (within 20 to 30 sec); subsequent doses should not exceed preceding dose by more than 0.1 to 0.2 mg (maximum 1 mg/dose).

Nasal Congestion

ADULTS & CHILDREN ³ 12 YR: Intranasal 1 to 2 sprays or 3 gtt of 0.25%, 0.5% or 1% solution q 4 hr. CHILDREN 6 to 12 YR: Intranasal 2 to 3 sprays of 0.25% solution in each nostril q 3 to 4 hr. CHILDREN 6 MO to 6 YR: Intranasal 1 to 2 gtt of 0.16% solution in each nostril q 3 hr.

Vasoconstriction/Pupil Dilation

ADULTS: Ophthalmic Instill 1 gtt 2.5% or 10% on upper limbus. If necessary, repeat after 1 hr.

Uveitis/Prevention of Synechiae

ADULTS: Ophthalmic Instill 2.5% or 10% phenylephrine plus atropine.

To Free Recently Formed Posterior Synechiae

ADULTS: Ophthalmic Instill 1 gtt of 2.5% or 10% to upper surface of cornea.

Wide-Angle Glaucoma

ADULTS: Ophthalmic Instill 1 gtt of 10% on upper surface of cornea prn.

Open-Angle Glaucoma

ADULTS: Ophthalmic Instill 2.5% or 10% solution in conjunction with miotics.

Surgery

ADULTS: Ophthalmic Instill 2.5% or 10% solution 30 to 60 min before operation as short-acting mydriatic.

RefrAction

ADULTS: Ophthalmic Instill 1 gtt 2.5% solution. CHILDREN: Ophthalmic Instill 1 gtt 2.5% solution.

Ophthalmascopic Examination

ADULTS: Ophthalmic Instill 1 gtt 2.5% solution in each eye.

Diagnostic Procedures/Provocative Test for Angleblock in Glaucoma

ADULTS: Ophthalmic Instill 2.5%.

Retinoscopy

ADULTS: Ophthalmic Instill 2.5% solution.

Blanching Test

ADULTS: Ophthalmic Instill 1–2 gtt of 2.5% solution.

Minor Eye Irritations

ADULTS: Ophthalmic Instill 1–2 gtt of 0.12% solution up to 4 times daily.

Interactions

Beta-blockers: Decrease phenylephrine's effect. General anesthetics: Arrhythmias. Guanethidine: May increase pressor response of phenylephrine; resulting in severe hypertension. Halogenated hydrocarbon anesthetics: May sensitize myocardium to effects of catecholamines. Use extreme caution to avoid arrhythmias. MAO inhibitors, furazolidone: May significantly increase pressor response resulting in hypertensive crisis and intracranial hemorrhage. Oxytoxic drugs: May cause severe persistent hypertension. Tricyclic antidepressants: May decrease or increase response; use with caution.

Lab Test Interferences None well documented.

Adverse Reactions

CV: Reflex bradycardia; hypertension; angina; arrhythmias. CNS: Headache; excitability; restlessness; tremor. EENT: With ophthalmic and intranasal forms: Transitory stinging on initial instillation; blurring of vision; rebound congestion.

Precautions

Pregnancy: Category C. Lactation: Undetermined. Children: Ophthalmic use of phenylephrine 10% is contraindicated in infants. Special-risk patients: Administer drug with caution to patients with hyperthyroidism, bradycardia, partial heart block, myocardial disease, prostatic hypertrophy, diabetes mellitus, increased IOP or severe arteriosclerosis. Hypovolemia: Avoid use in uncorrected hypovolemic states unless used as temporary emergency measure to maintain coronary and cerebral flow and in patients with tachyarrhythmias or ventricular fibrillation. Sulfite sensitivity: Use drug with caution in sulfite-sensitive individuals; some commercial preparations contain sodium bisulfite. Narrow-angle glaucoma: Ordinarily any mydriatic is contraindicated in patients with glaucoma. However, when temporary dilation of pupil may free adhesions or when vasoconstriction of intrinsic vessels may lower intraocular tension, these advantages may temporarily outweigh danger from coincident dilation of pupil. Corneal effects: If corneal epithelium has been denuded or damaged, corneal clouding may occur if phenylephrine 10% is instilled. Rebound congestion: May occur with extended use of intranasal or ophthalmic forms.

PATIENT CARE CONSIDERATIONS

Administration/Storage

For vasopressor use, administer medication via continuous pump infusion. Administer IV through large vein, preferably central vein. Titrate carefully to avoid hypotension.
With intranasal administration, do not share container. Instill spray into nose with head upright. Have patient sniff hard for a few minutes after administration. To instill drops, have patient recline on bed, hang head over edge and instill drops. Have patient remain in this position for several minutes after using and turn head from side to side. Do not allow tip of container to touch nasal passage. Discard after medication is no longer needed.
To instill ophthalmic solution tilt patient's head back, hold dropper over eye, drop medication inside lower lid, apply pressure to inside corner of eye for 1 min. Take care not to touch dropper to eye.
Prolonged exposure of ophthalmic solution to air or strong light may cause oxidation and discoloration. Do not use if solution is discolored or cloudy or contains precipitate.
Store parenteral and nasal solution at room temperature and protect from light.

Assessment/Interventions

Obtain patient history, including drug history and any known allergies. Note history of cardiovascular disease such as hypertension and assess for MAO inhibitor use.
For ocular or ophthalmic use, assess for intraocular lens implants due to possibility of dislodging lens. Also assess for history of damaged corneal epithelium.
Check BP and pulse frequently.
Monitor hemodynamic function.
Observe IV site for extravasation and infiltration.

OVERDOSAGE: SIGNS & SYMPTOMS
	Severe hypertension, vomiting, ventricular extrasystoles, short paroxysms of ventricular tachycardia, sensation of fullness in head, tingling of extremities, somnolence, sedation, coma, profuse sweating, hypotension, shock

Patient/Family Education

Intranasal

Advise patient that intranasal form is for short-term use only and should not be used for more than 3 to 5 days.
Inform patient that stinging, burning, or drying of the nose or an increase in nasal discharge may occur with intranasal form.
Instruct patient to gradually stop taking intranasal form of this medicine rather than abruptly discontinuing it because rebound congestion can occur with sudden withdrawal. First stop using drug in one nostril and then in both nostrils.

Ophthalmic

Caution patient that ophthalmic form of drug can cause discoloration of contact lenses and advise patient to wear glasses during therapy.
Instruct patient not to use ophthalmic form for > 72 hr without consulting physician.
Advise patient to discontinue drug and notify physician if severe eye pain, headache, vision changes, floating spots, acute eye redness, pain with light exposure, insomnia, dizziness, weakness, tremor, or irregular heartbeat occurs.
Advise patient that drug may cause temporary blurred or unstable vision, and to use caution while driving or performing other tasks requiring mental alertness.