Pseudoephedrine is a decongestant that can provide temporary relief from nasal congestion and other cold and flu symptoms like coughing. It works by constricting blood vessels in the nasal passages, reducing swelling and congestion. Pseudoephedrine is found in many popular over-the-counter cold medications, but you have to specifically look for cough syrups that contain it.
What is pseudoephedrine?
Pseudoephedrine is a sympathomimetic amine that is structurally similar to ephedrine. It works by stimulating alpha and beta adrenergic receptors which causes vasoconstriction or narrowing of the blood vessels. This decreases inflammation and congestion in the nasal passages and sinuses. Pseudoephedrine is an effective nasal decongestant and is a common ingredient in many cold and allergy medications including some cough syrups.
How does pseudoephedrine relieve coughs?
While pseudoephedrine is primarily used as a decongestant, it can also help relieve coughs associated with colds and respiratory illnesses. Coughs are frequently caused by excessive nasal drainage dripping down the back of the throat which triggers the cough reflex. By constricting blood vessels and reducing nasal congestion, pseudoephedrine minimizes postnasal drip which can in turn suppress the cough. Less nasal drainage means less irritation to trigger coughing.
Is pseudoephedrine an antihistamine?
No, pseudoephedrine is not an antihistamine. Antihistamines like diphenhydramine (Benadryl) work by blocking histamines which are chemicals released by the body during an allergic reaction. Pseudoephedrine works differently by stimulating alpha and beta receptors to shrink nasal blood vessels. The two medications relieve congestion through different mechanisms of action. Pseudoephedrine is considered a decongestant while antihistamines prevent or reduce allergic reactions. They may be found together in certain combination medications.
Cough Syrups with Pseudoephedrine
There are a few major brands of cough syrup that contain pseudoephedrine as an active ingredient:
Mucinex D
Mucinex D is a prominent over-the-counter cough syrup that includes both the cough suppressant dextromethorphan along with pseudoephedrine as a nasal decongestant. The “D” in the name indicates that pseudoephedrine is present. Mucinex D provides relief for chest congestion, mucus, coughing, nasal congestion and sinus pressure.
Robitussin Cough + Chest Congestion DM
Robitussin makes numerous cough and cold formulations, but their Cough + Chest Congestion DM syrup combines the expectorant guaifenesin with pseudoephedrine. The “DM” refers to its pseudoephedrine content. It thins and loosens mucus while pseudoephedrine tackles nasal congestion and postnasal drip that triggers coughs.
Delsym 12 Hour Cough Relief Plus
Delsym 12 Hour Cough Relief Plus contains the cough suppressant dextromethorphan polistirex along with pseudoephedrine. Its extended release formulation provides long lasting relief for up to 12 hours. The “Plus” in the name indicates that it includes pseudoephedrine as an added decongestant.
Vicks DayQuil Cough
Vicks DayQuil Cough combines acetaminophen for pain and fever reduction with pseudoephedrine to target nasal congestion as well as coughs. DayQuil formulas with pseudoephedrine clearly advertise “Sinus & Nasal Decongestant” on the label. Other DayQuil products may not contain pseudoephedrine.
Theraflu Daytime Severe Cold and Cough
Theraflu Daytime Severe Cold and Cough provides multiple symptom relief. It includes pseudoephedrine and an antitussive for cough suppression. Phenylephrine is used for nasal decongestion. Acetaminophen is present for pain and fever reduction. This Theraflu product specifically lists pseudoephedrine as an active ingredient.
Pseudoephedrine Dosage
Pseudoephedrine cough syrups are available in both regular and extended release formulations. The regular strength products typically provide:
- Adults: 30 mg pseudoephedrine every 4 to 6 hours as needed
- Children ages 6 to under 12: 15 mg pseudoephedrine every 4 to 6 hours as needed
Extended release pseudoephedrine cough syrups contain larger doses that are slowly released over 12 hours or longer. Common extended release dosages include:
- Adults: 120 mg pseudoephedrine every 12 hours
- Children ages 6 to under 12: 60 mg pseudoephedrine every 12 hours
Always follow the dosage directions on the specific cough syrup packaging as concentrations can vary between products. Pseudoephedrine oral dosages depend on the patient’s age and the formulation. Tablets and syrups are available in immediate and extended release forms.
Pseudoephedrine Dosage Table
| Age | Regular Strength Dose | Extended Release Dose |
|---|---|---|
| Adults 18 years and older | 30 mg every 4-6 hours as needed | 120 mg every 12 hours |
| Children 6-12 years | 15 mg every 4-6 hours as needed | 60 mg every 12 hours |
| Children under 6 years | Not recommended | Not recommended |
Pseudoephedrine Precautions
While generally safe and effective when used as directed, there are some precautions to be aware of with pseudoephedrine:
- Do not use pseudoephedrine if you have heart disease, high blood pressure, thyroid disease, diabetes, or difficulty urinating.
- Pseudoephedrine may increase blood pressure and heart rate or cause insomnia, anxiety, and restlessness.
- Do not take pseudoephedrine within 14 days of taking certain antidepressants known as MAO inhibitors.
- Avoid other stimulant drugs like amphetamines or caffeine when taking pseudoephedrine.
- Pseudoephedrine can pass into breast milk and may harm a nursing infant so use caution when breastfeeding.
Always talk to your doctor before taking pseudoephedrine if you have any medical conditions or take other medications. Discontinue use if nervousness, dizziness, or sleeplessness occurs. Seek medical help if symptoms worsen or persist for more than 7 days.
Pseudoephedrine Drug Interactions
The stimulant effects of pseudoephedrine can potentially interact with numerous medications. Some significant pseudoephedrine drug interactions to be aware of include:
- Antidepressants like MAO inhibitors – hypertensive crisis risk
- Stimulants like amphetamines – increased side effects
- Blood pressure medications – decreased efficacy
- Cold and allergy medications – overdose due to duplicated ingredients
- Narcotic pain relievers – exacerbated side effects
Always read medication labels carefully and talk to your pharmacist about potential interactions when purchasing new over-the-counter medicines. Let your healthcare provider know about all prescription and non-prescription medications you are taking before starting pseudoephedrine.
Pseudoephedrine and Blood Pressure
Pseudoephedrine is generally considered safe for people with controlled high blood pressure. However, it can potentially worsen uncontrolled or extremely high blood pressure. People with hypertension or heart disease should use caution when taking pseudoephedrine as a decongestant.
The stimulant actions of pseudoephedrine can increase blood pressure and heart rate in some individuals. People with blood pressure issues may experience pseudoephedrine side effects like:
- Increased blood pressure
- Rapid or irregular heart rate
- Cardiac arrhythmias
- Heart palpitations
Avoid pseudoephedrine if you have uncontrolled blood pressure or severe cardiovascular disease. Talk to your doctor about the risks before using cough syrups containing pseudoephedrine if you have high blood pressure or heart issues.
Pseudoephedrine Restrictions
Although available over-the-counter, there are some legal restrictions in place for purchasing pseudoephedrine products:
- A photo ID is required to purchase pseudoephedrine cough syrups from the pharmacy counter in many states.
- Pseudoephedrine sales may be limited to certain quantities like no more than 3.6 grams per day or 9 grams per month.
- Pharmacies track pseudoephedrine purchases in a controlled substance monitoring program.
- You must be 18 years or older to purchase pseudoephedrine cough syrups.
These rules help prevent the diversion of pseudoephedrine into illegal methamphetamine production. While inconvenient, the restrictions allow continued consumer access to beneficial over-the-counter cold and allergy relief products containing pseudoephedrine as a nasal decongestant.
Pseudoephedrine vs Phenylephrine
Both pseudoephedrine and phenylephrine are commonly used as oral nasal decongestants in over-the-counter medications. Some key differences between them include:
- Mechanism – Pseudoephedrine is an alpha and beta adrenergic agonist while phenylephrine is primarily an alpha-1 adrenergic agonist.
- Effectiveness – Studies show pseudoephedrine provides greater congestion relief than phenylephrine.
- Stimulation – Pseudoephedrine is more likely to increase blood pressure, heart rate, anxiety and insomnia.
- Regulation – Pseudoephedrine sales are strictly regulated while phenylephrine is more readily available.
In general, pseudoephedrine is considered more effective as a nasal and sinus decongestant but more likely to cause stimulant side effects. Phenylephrine is less potent but has fewer restrictions. Check active ingredients if stimulant side effects are a concern.
Pseudoephedrine vs Ephedrine
Although their names sound alike, there are important chemical differences between pseudoephedrine and ephedrine:
- Source – Pseudoephedrine is synthesized from yeast fermentation while ephedrine comes from the ephedra plant.
- Structure – Pseudoephedrine only contains one chiral center while ephedrine has two.
- Strength – Ephedrine is considered more potent with greater stimulant effects.
- Legality – Pseudoephedrine is approved OTC while ephedrine is a banned controlled substance.
In summary, pseudoephedrine is the milder, legal over-the-counter form of ephedrine available in cough syrups and cold medicines. While similar, pseudoephedrine does not provide the same stimulant “high” as the banned natural product ephedrine.
Conclusion
Pseudoephedrine is an effective nasal decongestant that can also minimize coughs associated with postnasal drip. Many popular over-the-counter cold and cough syrup brands such as Mucinex D, Robitussin DM, Vicks DayQuil Cough, and Theraflu Severe Cold & Cough contain pseudoephedrine as an active ingredient. Look for “D” or “DM” labeling to identify cough syrups with added pseudoephedrine. Though regulated, pseudoephedrine remains available without a prescription in most states to provide safe congestion relief when used as directed. Talk to your doctor or pharmacist if you have any medical conditions before using cough syrups containing pseudoephedrine. Proper use can help dry up excessive nasal drainage and suppress coughs for cold and flu relief.
