Generic Name: pseudoephedrine

Brand Names: Sudafed, Nexafed, Zephrex-D

Drug Class: Decongestants, Systemic

What is pseudoephedrine, and what is it used for?

Pseudoephedrine is a medication available over the counter (OTC) used for temporary relief from sinus congestion and nasal congestion caused by cold, hay fever, upper respiratory infections, and allergies.

Pseudoephedrine works by constricting the blood vessels in the respiratory passage, which promotes drainage of fluids and makes breathing easier.

Pseudoephedrine works by stimulating alpha adrenergic receptors, protein molecules in smooth muscles around blood vessels, which make them contract when stimulated by the neurohormones epinephrine and norepinephrine. Stimulation of alpha receptors in the respiratory mucous tissue constricts the blood vessels and decreases leakage of fluid, reducing congestion. Pseudoephedrine also stimulates beta receptors which cause relaxation of the bronchial passage and increase in heart rate and force of heart muscle contraction.

In addition to nasal and sinus congestion relief, off-label decongestant uses of pseudoephedrine include:

  • Reduction of breast milk production in nursing mothers with excessive lactation
  • Relief from priapism, a condition of painful and prolonged erection because of blood vessel constriction and trapping of blood in the penis

Because of its central nervous system (CNS) stimulant properties and structural similarity to amphetamine, pseudoephedrine is also misused as a street drug in place of or to produce amphetamine or methamphetamine. Some manufacturers now use advanced technology in the manufacture of pseudoephedrine tablets to limit the extraction of pseudoephedrine from the tablets and deter manufacturing of methamphetamine.

What are the side effects of pseudoephedrine?

Common side effects of pseudoephedrine include:

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

  • Serious heart symptoms include fast or pounding heartbeats, fluttering in your chest, shortness of breath, and sudden dizziness;
  • Severe headache, confusion, slurred speech, severe weakness, vomiting, loss of coordination, feeling unsteady;
  • Severe nervous system reaction with very stiff muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, and feeling like you might pass out; or
  • Serious eye symptoms include blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

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What are the dosages of pseudoephedrine?

Tablet, Immediate-Release

  • 30 mg
  • 60 mg
  • 120 mg

Tablet, Extended-Release

  • 120 mg
  • 240 mg

Tablet, IMPEDE Technology (Nexafed)

  • 30 mg
  • IMPEDE technology utilizes an advanced polymer matrix to limit extraction of pseudoephedrine from tablets and deter methamphetamine manufacturing

Tablet, TAREX technology (Zephrex-D)

  • 30 mg
  • TAREX technology utilizes an advanced polymer matrix to limit extraction of pseudoephedrine from tablets and deter methamphetamine manufacturing



Nasal Congestion

Immediate release: 60 mg orally every 4-6 hours as needed

Extended release: 120 mg orally every 12 hours or 240 mg orally every 24 hours

Priapism (Off-label)

  • 60-120 mg orally

Hyperlactation (Off-label)

  • Immediate release: 30 mg as a single dose. If milk production is not decreased after 8 to 12 hours, may administer a single dose of 60 mg.
  • 30 to 60 mg once to twice daily as needed


Nasal Congestion

  • Children below 2 years: Safety and efficacy not established
  • Children 2-6 years: 5-30 mg orally every 4-6 hours as needed
  • Children 6-12 years: 30 mg orally every 4-6 hours, OR 4 mg/kg/day divided every 6 hours; not to exceed 120 mg/day  
  • Children above 12 years: 60 mg orally every 6 hours as needed (immediate release); alternatively, 120 mg PO every 12 hours (extended release) or 240 mg orally every 24 hours (extended release)

Dosing Considerations

  • Potential toxic dose in children below 6 years: 11 mg/kg


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  • Pseudoephedrine overdose may cause symptoms that include giddiness, headache, nausea, vomiting, sweating, thirst, difficulty urinating, muscle weakness, anxiety, insomnia, toxic psychosis, increased heart rate and palpitations. Severe overdose may lead to irregular heart rhythm, circulatory collapse, convulsions, coma and respiratory failure.
  • Overdose of pseudoephedrine is treated with symptomatic and supportive care. Any undigested drug in the gastrointestinal tract may be eliminated with gastric lavage and activated charcoal administration.

What drugs interact with pseudoephedrine?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

  • Severe interactions of pseudoephedrine include:
  • Pseudoephedrine has serious interactions with at least 26 different drugs.
  • Pseudoephedrine has moderate interactions with at least 73 different drugs.
  • Mild interactions of pseudoephedrine include:
    • desmopressin

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or health care provider if you have any questions about the medication.

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Pregnancy and breastfeeding

  • Pseudoephedrine is not the preferred agent for treating nasal congestion during pregnancy, it can cause fetal harm.
  • Do not use pseudoephedrine during the first trimester of pregnancy, and avoid use for a prolonged period later in pregnancy.
  • Pseudoephedrine is present in breast milk. The drug can reduce milk production and limited data report irritability in the breastfed infant.

What else should I know about pseudoephedrine?

  • Follow label instructions exactly if you take OTC pseudoephedrine.
  • Do not administer OTC pseudoephedrine to children below 4 years. Check with your healthcare provider before administering it to children above 2 years.
  • If you take OTC pseudoephedrine, consult your healthcare provider if symptoms do not improve within 7 days or are accompanied by fever. Discontinue the drug and contact your healthcare provider if nervousness, dizziness, or sleeplessness occur.
  • Store safely out of children’s reach.
  • In case of overdose, seek medical help or contact Poison Control.

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Medically Reviewed on 8/9/2022