DayQuil NyQuil Combo Package With Text - Does Amoxicillin Interact With DayQuil?


The antibiotic amoxicillin is safe to take with DayQuil. There is no interaction between them.

DayQuil is a combination ingredient cough/cold/flu product which 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 anti-pyretic.

Dextromethorphan is a cough suppressant, using 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.

Answer Summary

There is no drug interaction between DayQuil and amoxicillin. They can safely be 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)

  1. ^ Amoxicillin Prescribing Information. AccessFDA
  2. ^ DayQuil Manufacturer Website.