Pseudoephedrine (Sudafed) for Runny Nose, Congestion, and Other Cold Symptoms

Pseudoephedrine is an over-the-counter (OTC) medication typically used for a runny nose and sinus congestion. Known by the brand name Sudafed, it is a drug classified as a nasal decongestant. These drugs stop a runny nose and dry up your sinuses.

Pseudoephedrine only treats symptoms caused by a common cold, sinusitis, allergies, and similar conditions. It is not a cure for viral or bacterial illness. 

This article details what Sudafed is, other pseudoephedrine brand names, and how it is safely used. It also discusses pseudoephedrine side effects and pseudoephedrine abuse.

Common Brand Names

Pseudoephedrine works by temporarily narrowing the blood vessels in your sinuses. They can become swollen when you have a cold, allergies, or a sinus infection. It shrinks swollen nasal membranes, and reduces the swelling and hyperemia, the increased blood flow to nasal tissues.

In addition to using Sudafed to stop a runny nose, people may use other brands containing pseudoephedrine. They include:

• Biofed
• Cenafed
• Contac 12-Hour
• Decofed
• Dimetapp Decongestant
• Drixoral
• Efidac 24
• Suphedrin

You should note that Sudafed PE is actually made with phenylephrine, which is similar to but not the same as Sudafed with pseudoephedrine.

Products with pseudoephedrine are not the same as antihistamines like Benadryl, which contains diphenhydramine.

Uses of Pseudoephedrine

The most common indication for pseudoephedrine is as a decongestant, for conditions such as nasal congestion, sinus congestion, and eustachian (ear) tube congestion.

You can take pseudoephedrine if:

• You have a runny nose, nasal congestion, sinus congestion, or severe symptoms related to allergies.
• You are healthy and have never had an allergic reaction to pseudoephedrine or another medication that contains pseudoephedrine.

If you have health problems, take other medications on a regular basis, or if you are pregnant, you should check with your healthcare provider and pharmacist before taking pseudoephedrine.

How It Is Taken

Pseudoephedrine comes in different forms, including:

• Regular tablets, taken every four to six hours
• 12-hour extended-release tablets
• 24-hour extended-release tablets
• Liquid, taken every four to six hours

It's important that you take the medication as prescribed. For example, only one 24-hour tablet should be taken each day; only two 12-hour tablets should be taken each day. It's also advised that you take the last dose of the day a few hours before bedtime, to avoid disrupting your sleep.

Sudafed and other brands are available over-the-counter in both child and adult formulas, so make sure that the formula you buy is age-appropriate.

Pseudoephedrine Side Effects

Pseudoephedrine is also classified as an alpha-adrenoceptor and beta-adrenoceptor agonist. Alpha and beta refer to the types of nerve receptors that control the constriction of smooth muscles, such as those in blood vessels.

By activating these receptors, pseudoephedrine causes vasoconstriction (the narrowing of blood vessels). Because these receptors are not only located in nasal passages, pseudoephedrine can cause the constriction of other smooth muscles, too.

For example, it can stimulate the heart rate and slow parts of the digestive tract.

Common side effects include:

• Restlessness
• Nausea
• Anxiety
• Weakness
• Headache
• Insomnia
• Flushing
• Trembling
• Itching

Who Shouldn't Take Sudafed?

Pseudoephedrine is contraindicated for use in certain people in whom treatment may pose health risks. It should never be used if:

• You have had an allergic reaction to it in the past.
• You are taking any medications in a class called MAO inhibitors, such as Marplan (isocarboxazid), Nardil (phenelzine), Eldepryl (selegiline) and Parnate (tranylcypromine). If you have not taken MAO inhibitors within 14 days, it is safe to take pseudoephedrine.
• You have a history of high blood pressure, thyroid disease, heart disease, an enlarged prostate gland, or diabetes, without seeing guidance or discussing risks first.

Newborns should not be given pseudoephedrine, nor should women who are breastfeeding. Notify your healthcare provider and pharmacist if you have any of these conditions.

Pseudoephedrine Abuse

In March 2006, the Combat Methamphetamine Epidemic Act of 2005 became law and was incorporated into the Patriot Act.

Methamphetamines are highly addictive street drugs that are "cooked" in illegal labs using over-the-counter pseudoephedrine and other household ingredients.

Pseudoephedrine can be chemically altered to make methamphetamine. The drugs can then be swallowed, inhaled, injected, or smoked to get the stimulant high.

A Word From Verywell

As a nasal decongestant, pseudoephedrine offers benefits to people with runny nose symptoms due to a cold or the flu. The medication also has side effects and, for some people, may present risks when using it. Talk to your healthcare provider or pharmacist about pseudoephedrine use.