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.


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

Asked by Cher On Oct 01, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Oct 01, 2022
Last updated Jun 14, 2024

Key points

  • There is no interaction between amoxicillin and DayQuil. They can be used together safely.


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.


  • Amoxicillin Prescribing Information, AccessFDA
  • DayQuil Manufacturer Website, Vicks
  • Dextromethorphan Monograph, PubChem

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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