is It Safe To Take DayQuil And A Z-Pack Together?
In our latest question and answer, the pharmacist discusses whether or not it is safe to take the antibiotic azithromycin (Z-Pack) with Dayquil.

Question
Is it safe to take DayQuil with a Z-Pak?

Answered by Dr. Brian Staiger, PharmD
Medical Content Reviewed By HelloPharmacist
Staff
Last updated Apr 01, 2025
Key points
- Azithromycin (the antibiotic in the Z-Pack) has no known interaction with DayQuil or DayQuil Severe.
Answer
Yes, it is safe to take DayQuil and a Z-Pak (azithromycin) together. There is no known interaction between the two.
It is important to remember that DayQuil is a combination ingredient product, and contains multiple drugs. All must be considered when discussing whether or not there are interactions.
Fortunately, none of the ingredients in DayQuil interact with a Z-Pak.
The ingredients in DayQuil are as follows:
- Acetaminophen
- Dextromethorphan
- Phenylephrine
DayQuil also comes in a 'severe' formula and is known as DayQuil Severe. It contains one additional ingredient:
- Acetaminophen
- Dextromethorphan
- Phenylephrine
- Guaifenesin
Just like DayQuil, DayQuil Severe doesn't interact with a Z-Pak.
In fact, A Z-Pak is safe to take with most over-the-counter medications.
The only ones you should avoid are the following:
- Antacids
- Loperamide (Imodium)
I will touch on each of these briefly below.
Antacids: Use Caution
Anything over that contains aluminum or magnesium (e.g. Gaviscon, Mylanta) should not be taken at the same take as a Z-Pak since they can decrease the absorption of the antibiotic, which may make it less effective.
The prescribing information for azithromycin states this specifically:
Patients should also be cautioned not to take aluminum- and magnesium-containing antacids and azithromycin simultaneously.
Loperamide: Use Caution
Loperamide, the active ingredient in Imodium-AD, should generally not be taken with a Z-Pak unless directed by your doctor.
Both loperamide (in high doses) and azithromycin are associated with cardiac side effects like QT prolongation.
The FDA has posted safety communications regarding both drugs (loperamide safety announcement; azithromycin safety announcement).
Final Words
Thanks for reaching out!
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Dr. Brian Staiger, PharmD
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