Taking DayQuil With Zyrtec (Cetirizine)

In our latest question and answer, the pharmacist discusses whether or not DayQuil can be taken with Zyrtec (cetirizine).


Can you take DayQuil and Zyrtec together?

Asked by Jimmi On Mar 12, 2018

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Mar 23, 2018

Zyrtec (cetirizine) and Dayquil may be safely taken together as there is no drug interaction between the two medications.

Taking DayQuil With Zyrtec (Cetirizine)


Dayquil is a combination ingredient cough/cold/flu medication that contains the following ingredients:

  • Acetaminophen (Pain reliever/fever reducer)
  • Dextromethorphan (Cough suppressant)
  • Phenylephrine  (Nasal decongestant)

While DayQuil has a number of ingredients that will help with cold and flu symptoms, it does not contain an antihistamine. Therefore, if you have seasonal allergies, DayQuil will not prevent them from occurring. It often is a good idea to combine an antihistamine, such as Zrytec (cetirizine) with DayQuil to provide all-around symptom relief.

Zyrtec (cetirizine)

Zyrtec is a "second generation" antihistamine that is an effective all day (i.e. 24 hour) allergy medication. Most second generation antihistamines, such as Claritin and Allegra, do not cause drowsiness or sedation. However,  Zyrtec is not considered non-drowsy. The prescribing information for Zyrtec shows around 13% of users will experience sedation or drowsiness.

Zyrtec is beneficial for preventing allergy symptoms such as:

  • Running nose
  • Congestion
  • Post nasal drip
  • Itchy, watery eyes

DayQuil With Zyrtec

DayQuil and Zyrtec can be taken together, and is sometimes recommended based on your symptoms. It is important to be aware however, the Zyrtec may cause drowsiness in some individuals. If you are looking for a "non-drowsy" antihistamine to take with DayQuil, consider Allegra or Claritin.


  • DayQuil and Zyrtec can be used together. There is no interaction between the two drugs.

About the Pharmacist

Dr. Brian Staiger Pharm.D

Dr. Brian Staiger is a licensed pharmacist in New York State and the founder of PharmacistAnswers.com. He graduated from the University At Buffalo with a Doctor of Pharmacy degree in 2010. He has been featured in numerous publications including the Huffington Post as well as a variety of health and pharmacy-related blogs. Please feel free to reach out to him directly if you have any inquiries or want to connect! He's answered thousands of medication and pharmacy-related questions and he's ready to answer yours! Brian.Staiger@PharmacistAnswers.com Office: 716-389-3076

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