PHENYLEPHRINE HYDROCHLORIDE
Metaoxedrine
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Reviewed by
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September 1998
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Dose and Administration
- Instil one drop in each eye before eye examination as per the
ROP guideline.
Indications
Is used in conjunction with cyclopentolate hydrochloride
to dilate the pupil in preparation for eye examination.
- All babies at risk of severe ROP.
- Intraocular surgery pre and postoperatively.
Contraindications and Precautions
- Known hypersensitivity to phenylephrine.
- Severe hypertension, ventricular tachycardia.
- Caution in neonates with hyperthyroidism, hypertension, myocardial disease, heart block, bradycardia, bronchopulmonary
dysplasia.
Clinical Pharmacology
Phenylephrine is a sympathomimetic
agent with mainly direct effects on adrenergic receptors. Produces mydriasis
without cycloplegia. It also acts as a conjunctival decongestant. The effect
lasts several hours.
Phenylephrine may lower intraocular pressure temporarily.
Systemic absorption from conjunctival membranes can occur.
Possible Adverse Effect
- Reflex bradycardia, ventricular dysrhythmias, tachycardia.
- Excitability, headache, lacrimation, conjunctival allergy.
- Increase in blood pressure.
- May cause local discomfort.
Special Considerations
- Solutions stronger than 2.5% are NOT recommended in the newborn.
- Interactions - beta-blocker: may cause arrhythmias.
- See the ROP guideline.