Can You Take Zyrtec With Sudafed?

In our latest question and answer, the pharmacist discusses whether or not it is safe to use Zyrtec (cetirizine) and Sudafed (pseudoephedrine) together.

3 min read Updated Jun 2026 Read by 21,512 people
Can You Take Zyrtec With Sudafed?
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Marcia asked

Can you take Zyrtec with Sudafed? I have bad allergies and Zyrtec, while working somewhat, isn't touching my nasal congestion. I need something to help me breathe and was wondering if using Sudafed was safe with Zyrtec.

Apr 06, 2022
The quick answer
  • Zyrtec and Sudafed are safe to take together because they are different types of medications that do not interact with each other.
  • These two medications are often combined in over-the-counter products like Zyrtec-D to treat multiple allergy and cold symptoms at the same time.
  • If you purchase Zyrtec-D, you will need to show ID at the pharmacy counter since it must be stored securely by law, though no prescription is required.
A quick summary of Dr. Brian Staiger, PharmD's full answer below, condensed by AI from that answer only (not from any outside source). The pharmacist's answer is the source of record.
Medications in this answer — tap to explore

Thanks for reaching out! Always happy to help. Yes, Zyrtec (cetirizine) may safely be taken with Sudafed (pseudoephedrine) as there is no interaction between the two medications. In fact, both medications are available together in a variety of combination products over the counter, including:

  • Zyrtec-D
  • TopCare Allergy-D

Taking Zyrtec Sudafed

As mentioned above, Zyrtec and Sudafed are considered safe to take with each other. They are in different classes of medication (Zyrtec is an antihistamine while Sudafed is a decongestant) and do not interact with each other. They both can help to alleviate symptoms of allergies and of a cold/flu, including:

  • Runny nose
  • Nasal congestion
  • Sinus pressure
  • Sneezing
  • Postnasal drip

Since they are so often used together and cover most symptoms brought on by allergies and colds, they are available as a single product, Zyrtec-D (the D stands for decongestant).

If you want to purchase Zyrtec-D (or an equivalent generic product), be sure to go to the pharmacy for it since it must be stored securely pursuant to the laws enacted with the Combat Methamphetamine Act of 2005. You don't need a prescription for it, but you will need to show ID.

In the next sections, I discuss some additional information about each drug.

Zyrtec Information

Zyrtec (cetirizine) is classified as a second-generation antihistamine and has a duration of action of around 24 hours.

While most second-generation antihistamines (e.g. Claritin, Allegra) do not cause drowsiness or sedation, Zyrtec is not considered non-drowsy unfortunately. Clinical studies for Zyrtec have reported around 10-13% of users will experience some sort of sedative effect.

In addition to its use for allergies, it also can help relieve itching and hives. Most studies report that it has similar efficacy to Benadryl in this regard with the benefit of causing much less sedation.

I want to point out here that It's worth noting that Zyrtec-D is dosed every 12 hours rather than once daily. This is primarily because it contains 120 mg of extended-release pseudoephedrine, which is formulated for a 12-hour duration, along with 5 mg of cetirizine per tablet. Because of this, two doses per day are needed for around-the-clock coverage. Talk to your pharmacist before adjusting how you take Zyrtec-D, as the pseudoephedrine component has its own daily dosing limits that are important to follow.

Sudafed Information

Sudafed (pseudoephedrine) is a commonly used over-the-counter nasal decongestant.

It works by producing vasoconstriction in the nasal passages, shrinking swollen nasal membranes, which helps to alleviate nasal congestion.

Sudafed also acts to increase nasal airflow and drainage of sinus secretions. Sudafed products must be stored behind the pharmacy counter due to the Combat Methamphetamine Epidemic Act, so be sure to ask the pharmacy if you need to purchase the product. Final Words

Thanks again for contacting us and don't hesitate to do so again in the future.

References & sources
  1. Combat Methamphetamine Epidemic Act — DEA
  2. Cetirizine Monograph — PubChem
  3. Pseudoephedrine Monograph — PubChem
Glossary — Terms in This Answer
Antihistamine
A medication that blocks histamine, a chemical in the body that causes allergy symptoms like itching and sneezing.
Decongestant
A medication that reduces nasal congestion by shrinking swollen nasal tissues.
Second-generation antihistamine
A newer class of antihistamine designed to be safer and cause fewer side effects than older versions.
Sedation
A drowsy or sleepy state caused by medication.
Vasoconstriction
The narrowing of blood vessels, which reduces swelling and congestion.
Extended-release
A medication formulation designed to slowly release its active ingredients over a longer period of time.
Efficacy
The ability of a medication to produce the desired therapeutic effect.
Combat Methamphetamine Act
A law that restricts the sale and storage of certain medications containing pseudoephedrine to prevent illegal drug manufacturing.
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Dr. Brian Staiger, PharmD
About the pharmacist

Dr. Brian Staiger, PharmD

Clinical Pharmacy

Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified

Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...

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