What is Phenylephrine?
Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).
Phenylephrine 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 may also be used for other purposes not listed in this medication guide.
What is the most important information I should know about Phenylephrine?
Do not give this medication to a child younger than 4 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.
You should not use this medication if you are allergic to phenylephrine.
Do not use phenylephrine 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 take phenylephrine before these other drugs have cleared from your body.
Before you take phenylephrine, tell your doctor if you are allergic to any decongestants, or if you have heart disease, heart rhythm disorder, high blood pressure, circulation problems, diabetes, glaucoma, a thyroid disorder, kidney disease, an enlarged prostate or urination problems, anxiety, sleep problems, bipolar disorder or other mental illness.
Phenylephrine may interact with heart or blood pressure medications, antidepressants, diabetes medications, migraine headache medications, and other decongestants.
Never take more of the medicine than directed on the label or prescribed by your doctor.
Call your doctor if your symptoms do not improve after 7 days of using phenylephrine, or if they get worse and your also have a fever.
What should I discuss with my healthcare provider before taking Phenylephrine?
You should not use this medication if you are allergic to phenylephrine.
Do not use phenylephrine 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 take phenylephrine before these other drugs have cleared from your body.
If you have certain conditions, you may need a dose adjustment or special tests to safely use this medication. Before you take phenylephrine, tell your doctor if you are allergic to any decongestants, or if you have:
- heart disease, heart rhythm disorder
- high blood pressure
- circulation problems (such as Raynaud’s syndrome)
- diabetes
- glaucoma
- a thyroid disorder
- kidney disease
- an enlarged prostate or urination problems
- sleep problems, anxiety; or
- mental illness such as bipolar disorder
FDA pregnancy category C. Is not known whether this medication will harm an unborn baby. Before you take phenylephrine, tell doctor if you are pregnant.
Phenylephrine 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.
Disintegrating and liquid forms of cold medicine may contain sugar or artificial sweeteners (phenylalanine). This would be important to know if you have diabetes or phenylketonuria (PKU). Check the ingredients and warnings on the medication label if you are concerned about sugar or phenylalanine.
Phenylephrine Side Effects
What are the possible side effects of Phenylephrine?
Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Stop using phenylephrine and call your doctor at once if you have a serious side effect such as:
- severe dizziness, restless feeling, nervousness, or insomnia
- unusual thoughts or behavior
- feeling like you might pass out
- fast, pounding, or uneven heartbeat
- tremors or shaking
- numbness, tingling, or cold feeling in your hands or feet; or
- urinating less than usual or not at all
Less serious side effects may include:
- headache, dizziness
- feeling excited or restless (especially in children)
- upset stomach; or
- mild sleep problems
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Phenylephrine Interactions
What other drugs affect Phenylephrine?
Tell your doctor about all other medications you use, especially:
- other decongestants, including nasal sprays
- digoxin (digitalis, Lanoxin)
- medicine to treat diabetes
- medicines to treat high blood pressure such as reserpine, methyldopa (Aldomet), and others
- migraine headache medicine such as ergotamine (Ergomar), naratriptan (Amerge), sumatriptan (Imitrex) or zolmitriptan (Zomig)
- an antidepressant such as amitriptyline (Elavil), clomipramine (Anafranil), imipramine (Janimine, Tofranil), and others
- a beta-blocker such as atenolol (Tenormin), carvedilol (Coreg), metoprolol (Lopressor, Toprol), propranolol (Inderal), sotalol (Betapace), and others; or
- a calcium channel blocker such as amlodipine (Norvasc), diltiazem (Tiazac, Cartia, Cardizem), felodipine (Plendil), nifedipine (Procardia, Adalat), verapamil (Calan, Covera, Isoptin, Verelan), and others
This list is not complete and there may be other drugs that can interact with phenylephrine. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.
What should I avoid while taking Phenylephrine?
Do not use any other over-the-counter cold, allergy, or cough medication without first asking your doctor or pharmacist. Phenylephrine is contained in many medicines available over the counter. If you take certain products together you may accidentally take too much phenylephrine. Read the label of any other medicine you are using to see if it contains phenylephrine or another decongestant.
Avoid taking diet pills, caffeine pills, or other stimulants (such as ADHD medications) without your doctor’s advice. Taking a stimulant together with a decongestant can increase your risk of unpleasant side effects.
Avoid smoking. It can add to the effects of phenylephrine in decreasing blood flow, which can lead to uncomfortable symptoms.
Avoid drinking alcohol while you are taking phenylephrine.
Phenylephrine Dosage
How should I take Phenylephrine?
Use this medication exactly as directed on the label, or as it has been prescribed by your doctor. Do not use the medication in larger amounts, or use it for longer than recommended. Cold medicine is usually taken only for a short time until your symptoms clear up.
Do not give this medication to a child younger than 4 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.
You may take phenylephrine with food if it upsets your stomach.
Take the phenylephrine tablet with a full glass of water.
Measure the liquid form of phenylephrine with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.
The chewable phenylephrine tablet must be chewed thoroughly before you swallow it.
To use the phenylephrine disintegrating strip, place one strip on your tongue and allow it to dissolve without chewing.
To use the disintegrating tablet, make sure your hands are dry and peel back the foil from the blister package. Place the tablet on your tongue. It will begin to dissolve right away. Do not swallow the tablet whole. Allow it to dissolve in your mouth without chewing.
Phenylephrine is usually taken every 4 hours. Follow the directions on the medicine label. Never take more of the medicine than directed on the label or prescribed by your doctor.
Call your doctor if your symptoms do not improve after 7 days of using phenylephrine, or if they get worse and your also have a fever.
If you need to have any type of surgery, tell the surgeon ahead of time if you have taken a cold medicine within the past few days.
Store phenylephrine at room temperature away from moisture and heat. Keep the disintegrating tablets or strips in their package until you are ready to take one.
Throw away any unused phenylephrine after the expiration date on the label has passed. Do not flush this medication down a toilet. Ask your pharmacist about the safest way to dispose of unused medicines.
What happens if I overdose on Phenylephrine?
Seek emergency medical attention if you think you have used too much of this medicine.
Overdose symptoms may include feeling restless or nervous, severe dizziness, sweating, vomiting, hallucinations, fast or uneven heart rate, fainting, seizure (convulsions), and weak or shallow breathing.
What happens if I miss a dose of Phenylephrine?
Cold medicine is usually taken only as needed, so you may not be on a dosing schedule. If you are taking the medication regularly, take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at your next regularly scheduled time. Do not take extra medicine to make up the missed dose.
Sourced from everydayhealth.com