Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).

Phenylephrine nasal is used to treat nasal congestion and sinus pressure caused by allergies, the common cold, or the flu. Phenylephrine may be used to treat congestion of the tubes that drain fluid from your inner ears, called the eustachian (yoo-STAY-shun) tubes.

Phenylephrine nasal may also be used for purposes not listed in this medication guide.

Do not give this medication to a child younger than 4 years old. Always ask a doctor before giving cough or cold medicine to a child. Death can occur from the misuse of cough or cold medicine in very young children.

You should not use this medication if you are allergic to phenylephrine.

Do not use phenylephrine nasal if you have used linezolid (Zyvox) or procarbazine (Matulane), or if you have taken a monoamine oxidase inhibitor (MAOI) such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) in the last 14 days. Serious, life-threatening side effects can occur if you use phenylephrine before these other drugs have cleared from your body.

Before using phenylephrine nasal, tell your doctor if you are allergic to any decongestants, or if you have heart disease, heart rhythm disorder, high blood pressure, diabetes, glaucoma, a thyroid disorder, or an enlarged prostate or urination problems.

Phenylephrine may interact with heart or blood pressure medications, antidepressants, diabetes medications, and other decongestants.

Never use more of this medicine than directed on the label or prescribed by your doctor.

Call your doctor if your symptoms do not improve after 3 days of using phenylephrine nasal, or if they get worse and you also have a fever. Using phenylephrine nasal too long can damage the lining of your nasal passages and lead to chronic nasal congestion.

You should not use this medication if you are allergic to phenylephrine.

Do not use phenylephrine nasal if you have used linezolid (Zyvox) or procarbazine (Matulane), or if you have taken a monoamine oxidase inhibitor (MAOI) such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) in the last 14 days. Serious, life-threatening side effects can occur if you use phenylephrine before these other drugs have cleared from your body.

Ask a doctor or pharmacist if it is safe for you to use this medicine if you have:

• heart disease, heart rhythm disorder;

• high blood pressure;

• diabetes;

• glaucoma;

• a thyroid disorder; or

• an enlarged prostate or urination problems.

FDA pregnancy category C. Is not known whether this medication will harm an unborn baby. Before using phenylephrine nasal, tell doctor if you are pregnant.

Phenylephrine nasal may pass into breast milk and could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Older adults may be more likely to have side effects from this medication.