Phenylephrine

Jul 28, 2022

Generic name: phenylephrine (oral) [ FEN-il-EFF-rin ]
Brand names: Nasop, Sudafed PE, Sudogest PE, Neo-Synephrine, Ah-Chew D,  … show all 22 brands
Dosage forms: oral liquid (2.5 mg/5 mL); oral tablet (10 mg); oral tablet, chewable, extended release (tannate 10 mg); oral tablet, disintegrating (10 mg)
Drug classes:  Decongestants ,  Vasopressors

What is phenylephrine?

Phenylephrine  is a decongestant that is used to treat stuffy nose and sinus congestion caused by the  common cold ,  hay fever , or other  allergies .

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

Warnings

Do not use  phenylephrine  if you have used an  MAO inhibitor  in the past 14 days, such as  isocarboxazid ,  linezolid ,  methylene blue  injection,  phenelzine ,  rasagiline ,  selegiline , or  tranylcypromine .

Before taking this medicine

Do not use phenylephrine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

You should not use phenylephrine if you are allergic to it.

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

  • heart disease,  high blood pressure ;
  • diabetes;
  • a thyroid disorder;
  • an  enlarged prostate  and urination problems; or
  • any drug allergies.

Ask a doctor before using this medicine if you are pregnant or breast-feeding.

The liquid form of this medicine may contain phenylalanine. Check the medication label if you have  phenylketonuria  (PKU).

How should I take phenylephrine?

Use exactly as directed on the label, or as prescribed by your doctor. Cold medicine is only for short-term use until your symptoms clear up.

Always follow directions on the medicine label about giving cold medicine to a child.

You must chew the chewable tablet before you swallow it.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Remove an orally disintegrating tablet from the package only when you are ready to take the medicine. Place the tablet in your mouth and allow it to dissolve, without chewing. Swallow several times as the tablet dissolves.

Call your doctor if your symptoms do not improve after 7 days, or if you have a fever, rash, or headaches.

If you need surgery, tell your surgeon if you are currently using phenylephrine.

Store at room temperature away from moisture and heat. Do not freeze.

What happens if I miss a dose?

Since cold medicine is used when needed, you may not be on a dosing schedule. Skip any missed dose if it’s almost time for your next dose. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking phenylephrine?

Ask a doctor or pharmacist before using other cough or cold medicines that may contain similar ingredients.

Phenylephrine side effects

Get emergency medical help if you have signs of an allergic reaction:  hives ; difficulty breathing; swelling of your face, lips, tongue, or throat.

Phenylephrine may cause serious side effects. Stop using phenylephrine and call your doctor at once if you have:

  • fast, pounding, or  irregular heartbeat ;
  • severe  dizziness  or  nervousness ;
  • sleep problems ( insomnia ); or
  • increased blood pressure–severe  headache , blurred vision, pounding in your neck or ears.

Common side effects of phenylephrine may include:

  • flushing (warmth, redness, or tingly feeling);
  • loss of appetite; or
  • feeling restless or excited (especially in children).

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 side effects  (more detail)

Phenylephrine dosing information

Usual Adult Dose for Hypotension:

Perioperative dosing (patients undergoing surgery with neuraxial or general anesthesia):
Initial dose: 50 to 250 mcg by intravenous bolus (most common doses: 50 to 100 mcg)
Maintenance dose: 0.5 to 1.4 mcg/kg/min by intravenous continuous infusion (titrate to blood pressure goal)

Septic or Other Vasodilatory Shock:
0.5 to 6 mcg/kg/min by intravenous continuous infusion (titrate to blood pressure goal)
-No bolus
-Doses over 6 mcg/kg/min do not show significant incremental blood pressure increases.

Usual Adult Dose for Shock:

Perioperative dosing (patients undergoing surgery with neuraxial or general anesthesia):
Initial dose: 50 to 250 mcg by intravenous bolus (most common doses: 50 to 100 mcg)
Maintenance dose: 0.5 to 1.4 mcg/kg/min by intravenous continuous infusion (titrate to blood pressure goal)

Septic or Other Vasodilatory Shock:
0.5 to 6 mcg/kg/min by intravenous continuous infusion (titrate to blood pressure goal)
-No bolus
-Doses over 6 mcg/kg/min do not show significant incremental blood pressure increases.

Usual Adult Dose for Nasal Congestion:

10 mg orally every 4 hours
Maximum dose: 60 mg per 24 hours

Usual Pediatric Dose for Nasal Congestion:

12 years and older: 10 mg orally every 4 hours
Maximum dose: 60 mg per 24 hours

Detailed Phenylephrine dosage information

What other drugs will affect phenylephrine?

Many drugs can affect phenylephrine, and some drugs should not be used at the same time. Tell your doctor about all your current medicines and any medicine you start or stop using. This includes prescription and over-the-counter medicines,  vitamins , and  herbal products . Not all possible interactions are listed here.

source :: https://www.drugs.com/mtm/phenylephrine.html