Indication: Sudafed PE (phenylephrine) is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion.

Insight:

Sudafed PE is used to treat stuffy nose and sinus congestion caused by the common cold, hay fever, or other allergies.
Do not use this medicine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.
Do not give Sudafed PE to a child younger than 4 years of age. Always ask a physician before giving a cough or cold medicine to a child.
Adverse events include dizziness, irregular heartbeat, loss of appetite, and feeling restless.

Sources:

Sudafed Pe: Uses, Dosage & Side Effects - Drugs.com

sudafed pe image - Google Search