Phenylephrine Drug & Side Effects

Phenylephrine is a prescription ophthalmological solution used as an eyedrop. Doctors utilize phenylephrine to dilate pupils prior to an eye examination or ocular surgery, as well as to treat certain disorders that affect your eyes, such as glaucoma, inflammation of the uvea and uveitis.

Function

• Phenylephrine works by causing blood vessels in the eyes, as well as the iris, to constrict, which causes the pupil to dilate.

Time Frame

• The dilation caused by phenylephrine usually lasts between one and three hours, according to rxlist.com.

Drug Interactions

• When taken with cardiovascular beta-blocking medications, phenylephrine has the potential to cause hypertension, posing a risk for aneurysms in some patients. Drugs such as MAOI, tricyclic antidepressants and the psychiatric drug reserpine increase the risk of developing side effects from phenylephrine.

Risks

• The most common side effects of phenylephrine include burning or stinging in the eyes, headaches, sensitivity to sunlight and watery eyes. In rare instances the use of phenylephrine results in arrhythmia that could be fatal.

Considerations

• Because the effects of the drug on fetal development are unknown, doctors rarely prescribe phenylephrine for pregnant women. If you have a history of type 2 diabetes, heart disease, hypertension or hypotension, it may not be safe for you to take phenylephrine, according to the Mayo Clinic.