Phenylephrine Eye Drops are used as a topical ophthalmic solution to dilate the pupils as in certain local procedures and for the examination of the retina. It may be used as an OTC medicine for bloodshot eyes (allergic conjunctivitis).

Phenylephrine Eye Drops Uses:

• Mydriasis:
  • It is used to dilate the pupils for examination and local procedures.
  • It may be used as an OTC medicine for the symptomatic treatment of patients with red eyes (allergic conjunctivitis).

Phenylephrine Eye Drops Dose in Adults

Phenylephrine Eye Drops Dose in the treatment of Mydriasis:

• Type of Phenylephrine: Either a 2.5% or 10% solution.
• How to Use:
  • Instill (put in) 1 eye drop every 3 to 5 minutes.
• Maximum Dose:
  • Don't use more than 3 drops per eye in one session.
• Repeat if Needed:
  • If necessary, you can repeat the dose.

Phenylephrine Eye Drops Dose in Children

Phenylephrine Eye Drops Dose in the treatment of Mydriasis: Ophthalmic:

2.5% Solution:

• Who: Infants, Children, and Adolescents.
• When: Put in 1 drop 15 to 30 minutes before the procedure.
• How Often: Repeat every 3 to 5 minutes.
• Max Total Dose: Don't exceed 3 drops per eye.

10% Solution:

• Who: Children and Adolescents.
• When: Use 1 drop 15 to 30 minutes before the procedure.
• How Often: Administer every 3 to 5 minutes as necessary.
• Max Total Dose: Again, the maximum is 3 drops per eye.

This guidance is based on recommendations from the American Academy of Pediatrics in 2008.

Pregnancy Risk Factor C

• There haven't been studies on how phenylephrine eye drops specifically affect animals during pregnancy, so it's categorized as pregnancy category C.
• When given through a vein, phenylephrine does reach the baby through the placenta (you can find more details in the information about systemic phenylephrine).
• However, the amount of phenylephrine that gets into the body after using eye drops is usually less than when taken by mouth or through an IV.

Use during breastfeeding:

• We're not sure if phenylephrine gets into breast milk.
• So, the advice is to be careful when giving phenylephrine to breastfeeding moms, as there isn't enough information to guarantee it's safe.

Dose in Kidney Disease:

• The information from the manufacturer doesn't include changes in dosage for people with kidney problems.

Dose in Liver disease:

• According to the manufacturer's information, there are no recommended changes in dosage for individuals with liver problems.

Side effects of Phenylephrine Eye Drops:

At typical doses, systemic effects are uncommon.

• Ophthalmic:
  • Miosis (Rebound)
  • Visual Disturbance
  • Burning Sensation Of Eyes
  • Eye Irritation
  • Vitreous Opacity (Transient)

Contraindications to Phenylephrine Eye Drops:

For the 2.5% solution, the manufacturer doesn't list any reasons not to use it, meaning there are no specific conditions where it's prohibited.

For the 10% solution, it's not recommended for people with high blood pressure (hypertension), overactive thyroid (thyrotoxicosis), or infants under 1 year old.

Regarding allergies, there's not much information on whether people who are allergic to one eye decongestant might also react to this one. However, because some decongestants are similar, there's a possibility of an allergic reaction, although it's not guaranteed.

Warnings and precautions

Cardiovascular events

• While it's not common, there have been rare cases where serious heart issues like irregular heartbeats (ventricular arrhythmias) and heart attacks (myocardial infarction) have been reported with the use of the 10% solution.
• People who already have heart problems might be at a higher risk.
• In such cases, it's advisable for healthcare providers to think about using the 2.5% solution instead, which may be safer for these patients.

Hypertension:

• Using the 10% solution of phenylephrine can lead to a notable increase in blood pressure, and this risk is lower with the 2.5% solution.
• When dealing with children under 5 years old, individuals with an overactive thyroid (hyperthyroidism), or those with heart problems, it's important to be cautious with the 10% solution.
• For patients with conditions like thyroid or heart diseases, or if anyone experiences symptoms during treatment, it's recommended to closely monitor their blood pressure after using phenylephrine.

Rebound miosis

• There have been reports of rebound miosis occurring one day after using the treatment.
• Rebound miosis means the pupils, which were dilated before, constrict or become smaller again.
• When the drug is applied again, it might not have the same strong effect in dilating the pupils as it did initially.

Phenylephrine (ophthalmic): Drug Interaction

Monitoring Parameters:

Monitor the response to therapy.   

How to administer Phenylephrine Eye Drops?

• Hand Hygiene:
  • Wash your hands before and after applying the solution.
• Application Technique:
  • Only use the solution in your eyes.
  • Avoid touching the dropper tip to your eyelids or any other surfaces to prevent contamination.
• Where to Apply:
  • Apply the solution to the conjunctival fornix (unless told otherwise by your healthcare provider).
• Eye Protection:
  • Shield your eyes from bright lights when your pupils are dilated.

Mechanism of action of Phenylephrine Eye Drops:

• In straightforward terms, this substance is a powerful alpha-adrenergic agonist that doesn't have much beta-adrenergic activity.
• Its main effect is causing local blood vessels to constrict, which means they get narrower.

Onset and Duration of Action:

• Mydriasis (pupil dilation) begins about 15 minutes after application.
• Maximal mydriasis is typically achieved between 20 to 90 minutes.
• The effects usually last for about 3 to 8 hours.

Absorption:

• There's minimal absorption into the bloodstream, reducing the likelihood of systemic effects.

Plasma Peak Time:

• In the bloodstream, the substance reaches its highest concentration in less than 20 minutes after application (as per Kumar, 1986).

International Brand Names of Phenylephrine Eye Drops:

• Altafrin
• Minims Phenylephrine HCl

Phenylephrine Eye Drops Brand Names in Pakistan: