NyQuil bottle on bathroom counter

Answer

Hello and thanks for reaching out to us!

Treatment regimens for Helicobacter pylori (H. pylori) infections can vary based on a number of factors but generally, treatment consists of a combination of two to three antibiotics along with a PPI (proton pump inhibitor), like omeprazole. In some patients, Pepto Bismol (bismuth subsalicylate) is also added on.

The specific treatment you are taking is known as 'concomitant therapy' according to the ACG clinical guidelines for the treatment of Helicobacter pylori infections. It consists of:

There are a number of other drugs that also can used to treat these infections, including levofloxacin, doxycycline, tetracycline and rifabutin.

I list all these drugs because I want to be all-inclusive on the topic of whether or not NyQuil interacts with any of these.

Remember too that NyQuil contains more than one ingredient and NyQuil Severe contains an extra one at that. Original NyQuil contains:

NyQuil Severe contains:

Now, none of the active ingredients in NyQuil or NyQuil Severe are known to interact with the drugs used to treat H. pylori infections (i.e. doesn't interact with any of the antibiotics, PPIs or the Pepto-Bismol I talked about earlier).

However, NyQuil liquid contains alcohol (10% by volume).

Alcohol is not recommended to be consumed if you are taking the antibiotic metronidazole, a topic we have written about a few times.

In fact, the prescribing information for metronidazole states that alcohol use is a contraindication (i.e. should not be done) due to the risk of severe reactions:

Use of oral metronidazole is associated with a disulfiram-like reaction to alcohol, including abdominal cramps, nausea, vomiting, headaches, and flushing. Discontinue consumption of alcohol and products containing propylene glycol during and for at least three days after therapy with metronidazole

A 'disulfiram-like' reaction can occur because metronidazole can impede alcohol metabolism, thus increasing the risk of side effects (e.g. nausea, vomiting).

The amount of alcohol you actually consume if you take a dose of NyQuil is going to be quite low when you compare it to drinking an alcoholic beverage but nevertheless, any amount of alcohol with metronidazole has the potential to cause problems.

Therefore, since you are taking metronidazole, if you also want to take NyQuil to treat your cold symptoms, be sure that you are using the alcohol-free version or the LiquiCaps, which also don't contain alcohol.

As a final point, you generally want to avoid alcohol anyway if you are taking antibiotics since the risk of nausea can be increased when they are combined. Additionally, alcohol can worsen the symptoms of ulcers, which H. pylori infections can cause.

Be sure to reach out to us if you have any additional questions!


Summary

  • NyQuil (acetaminophen; dextromethorphan; doxylamine) and NyQuil Severe (acetaminophen; dextromethorphan; doxylamine; phenylephrine) do not interact with the most commonly used drugs to treat H. pylori infections.
  • However, some NyQuil products, like NyQuil liquid, contain alcohol, which shouldn't be consumed with one drug often used for H. pylori infections, metronidazole.

  • References
    1. Treatment regimens for Helicobacter pylori. UpToDate (Subscription Required)
    2. ACG Clinical Guideline: Treatment of Helicobacter pylori Infection. AJG
    3. NyQuil Manufacturer Website. Vicks
    4. Metronidazole Prescribing Information. AccessFDA