Can You Take NyQuil and ZzzQuil Together?

In our latest question and answer, the pharmacist discusses whether or not NyQuil and ZzzQuil can be taken together.

Question

Can you take ZzzQuil and NyQuil together?

Asked by Steve On Sep 02, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Sep 02, 2022
Last updated May 05, 2024

Key points

  • NyQuil and ZzzQuil should not be taken together. They both contain sedating antihistamines.

Answer

It is not safe to take ZzzQuil with NyQuil as both contain sedating "first generation" antihistamines. Using both together would be considered a therapeutic duplication and can increase the risk of side effects. ZzzQuil contains diphenhydramine, the same active ingredient in Benadryl. NyQuil contains doxylamine, also a sedating "first generation" antihistamine.

Interaction Between NyQuil and ZzzQuil: Details

  • Both NyQuil and ZzzQuil contain sedating, "first generation" antihistamines. Using both would be considered a therapeutic duplication and increases the risk of side effects.
  • Both drugs cause CNS (central nervous system) depression, which may result in a decrease in blood pressure and severe drowsiness. In combination with other CNS depressants, dangerous side effects such as respiratory depression are possible.
  • Both drugs have anticholinergic effects, potentially causing dehydration, dry mouth, dry eyes, and constipation.

Dosing Recommendations

Only take the NyQuil at bedtime if you need it for trouble sleeping and you are experiencing multiple cold symptoms. NyQuil is a combination medication that contains the following ingredients:

  • Acetaminophen (analgesic)
  • Dextromethorphan (cough suppressant)
  • Doxylamine (sedating antihistamine)

ZzzQuil contains only doxylamine as its active ingredient and should generally just be used as a sleep aid although it can help certain cold symptoms such as a runny nose and post nasal drip.

While you shouldn't take NyQuil and ZzzQuil together, you can take DayQuil and ZzzQuil together. DayQuil contains the following ingredients:

  • Acetaminophen (analgesic)
  • Dextromethorphan (cough suppressant)
  • Phenylephrine (nasal decongestant)

Taking DayQuil during the day and ZzzQuil at bedtime is safe.

Summary

Do not take the ZzzQuil and Nyquil together due to them both containing a sedating first-generation antihistamine (diphenhydramine and doxylamine respectively).

It is important to note that it is recommended that you do not use sleep aids for more than 2 weeks because it can alter your normal sleep patterns. If you still cannot sleep without medication after 2 weeks, please contact your doctor. Be sure to always read the ingredients on cold medication to ensure that you are not taking too much of the same drug or two drugs treating the same symptom.

Drink plenty of water while on these medications and do not drive or operate machinery while taking NyQuil or ZzzQuil.

References

  • NyQuil & ZzzQuil Manufacturer Website, Vicks

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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