Phenylephrine Injection

Generic name: Phenylephrine Injection [ fen-il-EF-rin ]
Brand name: Neo-Synephrine
Drug classes: Decongestants, Vasopressors

Medically reviewed by Drugs.com. Last updated on Jan 1, 2024.

Uses of Phenylephrine Injection:

It is used to treat low blood pressure.

What do I need to tell my doctor BEFORE I take Phenylephrine Injection?

If you are allergic to phenylephrine injection; any part of phenylephrine injection; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
If you have high blood pressure.
If you have taken certain drugs for depression or Parkinson's disease in the last 14 days. This includes isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline. Very high blood pressure may happen.
If you are taking any of these drugs: Linezolid or methylene blue.

This is not a list of all drugs or health problems that interact with phenylephrine injection.

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take phenylephrine injection with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take Phenylephrine Injection?

Tell all of your health care providers that you take phenylephrine injection. This includes your doctors, nurses, pharmacists, and dentists.
If you are allergic to sulfites, talk with your doctor. Some products have sulfites.
Have blood work checked as you have been told by the doctor. Talk with the doctor.
Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

How is this medicine (Phenylephrine Injection) best taken?

Use phenylephrine injection as ordered by your doctor. Read all information given to you. Follow all instructions closely.

This medicine is given as a shot into a vein or into a vein nonstop for a period of time.

What do I do if I miss a dose?

Call your doctor to find out what to do.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Signs of high blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
Chest pain or pressure.
Shakiness.
Signs of kidney problems like unable to pass urine, change in how much urine is passed, blood in the urine, or a big weight gain.
Fast, slow, or abnormal heartbeat.
Blurred eyesight.
Shortness of breath, a big weight gain, or swelling in the arms or legs.
Numbness or tingling in the hands or feet.
This medicine may cause tissue damage if the drug leaks from the vein. Tell your nurse if you have any redness, burning, pain, swelling, blisters, skin sores, or leaking of fluid where the drug is going into your body.

What are some other side effects of Phenylephrine Injection?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

Dizziness or headache.
Feeling nervous and excitable.
Trouble sleeping.
Restlessness.
Upset stomach or throwing up.
Sweating a lot.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out Phenylephrine Injection?

If you need to store phenylephrine injection at home, talk with your doctor, nurse, or pharmacist about how to store it.

Consumer Information Use and Disclaimer

If your symptoms or health problems do not get better or if they become worse, call your doctor.
Do not share your drugs with others and do not take anyone else's drugs.
Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about phenylephrine injection, please talk with your doctor, nurse, pharmacist, or other health care provider.
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.