phenylephrine ophthalmic

Action and Spectrum

Actions and spectrum: 

This drug acts directly on the α- adrenergic receptors present in the eye. This leads to the contraction of the dilator muscle present in the pupil and causes constriction of arterioles in the conjunctiva. 

Drug Interaction

Adverse Reaction

Adverse reactions 

Arrhythmia 

Blurred vision 

Syncope 

Headache 

Myocardial infarction 

Reactive hyperemia 

Transient keratitis 

Sensitivity to light 

Rebound myosis 

Subarachnoid hemorrhage 

Allergic conjunctivitis 

Transient stinging or burning 

Black Box Warning

Black box warning 

Do not drive vehicles until the vision is clear 

Contraindication / Caution

Contraindications/Caution 

Hypersensitivity 

Cardiac disorders 

Arteriosclerotic changes 

Hyperthyroidism 

Type 1 diabetes 

Children with lower body weight 

Rebound myosis 

Pregnancy / Lactation

Pregnancy & breastfeeding: 

Pregnancy consideration: 

US FDA pregnancy category: C 

Breastfeeding warnings: 

Data about the excretion of the drug into breast milk is not known. 

Pregnancy category: 

Category A: well-controlled and satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: There was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: There was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women. 

Category D: Adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits. 

Category X: Drugs listed in this category outweigh the risks over benefits. Hence, these categories of drugs need to be avoided by pregnant women. 

Category N: No data for the drug under this category is available. 

Pharmacology

Pharmacology: 

Phenylephrine ophthalmic is used for mydriatic effect by stimulating α-1 adrenergic receptors in the eye and alleviating eye redness, dryness, burning, and irritation which dilates pupils for examinations and treats eye conditions. 

Pharmacodynamics: 

Phenylephrine is a sympathomimetic amine with strong vasoconstrictive properties. Its impact on cardiac output and end organ perfusion that can vary depending on administration method, patient volume, heart rate, autonomic tone, and underlying cardiac conditions.
When administered ophthalmically it causes smooth muscle contraction and pupil dilation that is useful for fundoscopic exams, surgeries, and treating medical conditions. 

Pharmacokinetics: 

Absorption:   

Systemic absorption is minimal, peak plasma concentration can be achieved < 20 minutes. 

Distribution 

It is bound to plasma proteins. 

Metabolism: It undergoes hepatic metabolism primarily through enzymatic oxidation mediated by catechol-o-methyltransferase. 

Excretion: This drug is eliminated mainly through urine. 

Adminstartion

Administration: 

While using this drug ensure to wash your hands, tilt your head back, gently press on the skin below your lower eyelid, creating a small pocket. Drop the medicine into this space and release your eyelid. Close your eyes without blinking. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: phenylephrine ophthalmic 

Why do we use phenylephrine ophthalmic? 

This medication is used in the treatment of certain eye disorders. It is indicated in the treatment of eye redness and to produce mydriasis before eye examination. It acts as a decongestant by shrinking the blood vessels.