Can You Take Amoxicillin And DayQuil Together?
In our latest question and answer, our pharmacist discusses whether or not it is safe to take DayQuil with amoxicillin.

Question
I just got prescribed amoxicillin for a respiratory infection. I wanted to know if it was okay to use DayQuil with it.

Answered by Dr. Brian Staiger, PharmD
Medical Content Reviewed By HelloPharmacist
Staff
Last updated Apr 23, 2025
Key points
- There is no interaction between amoxicillin and DayQuil. They can be used together safely.
Answer
The antibiotic amoxicillin is safe to take with DayQuil. There is no interaction between them.
DayQuil is a combination ingredient cough/cold/flu product that contains three medications (DayQuil Severe has four):
- Acetaminophen
- Dextromethorphan
- Phenylephrine
- Guaifenesin (DayQuil Severe only)
Acetaminophen is the active ingredient in Tylenol as well. It is an analgesic and antipyretic.
Dextromethorphan is a cough suppressant, used for treating chronic, nonproductive coughs.
Phenylephrine is a nasal decongestant, similar to pseudoephedrine but is available over the counter (pseudoephedrine is also available without a prescription but must be in a locked case or behind the pharmacy counter).
Guaifenesin is an expectorant, which helps to loosen and thin bronchial secretions.
All of the ingredients in DayQuil (and DayQuil Severe) do not interact with amoxicillin. You can feel safe taking them together.
In fact, amoxicillin is safe with the vast majority of over-the-counter cough/cold and flu medications.
There is a very minor interaction with aspirin, as they both compete for protein binding sites. Using both has the risk of increasing the side effects of either drug. Nevertheless, even though an interaction is possible, they are often used together.
About Amoxicillin
Amoxicillin is a semisynthetic "aminopenicillin" similar to ampicillin and penicillin. However, it has a broader spectrum of activity effects than penicillin and is better absorbed than ampicillin (which allows it to be dosed less frequently).
Amoxicillin is used to treat a variety of infections including:
- Otitis media (ear infections)
- Bronchitis
- Sinusitis (sinus infection)
Amoxicillin can be taken with or without food. Food may reduce the risk of gastrointestinal side effects.
Amoxicillin is available in a variety of dosage forms, including:
- Tablets
- Capsules
- Suspension
- Extended-release tablets (Moxatag)
Final Words
Thanks for your question! Reach back out anytime.
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Dr. Brian Staiger, PharmD
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