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.
Can you take ZzzQuil and NyQuil together?
Sep 02, 2022- Do not take NyQuil and ZzzQuil together because both contain sedating antihistamines that can increase drowsiness and other side effects when combined.
- Taking both medications together can cause dangerous central nervous system depression, low blood pressure, and potentially respiratory depression.
- You can safely take DayQuil during the day and ZzzQuil at bedtime instead, since DayQuil does not contain a sedating antihistamine.
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 & sources
- NyQuil & ZzzQuil Manufacturer Website — Vicks
Glossary — Terms in This Answer
- Therapeutic duplication
- Taking two medications that contain the same active ingredient or work the same way in your body.
- Diphenhydramine
- A sedating antihistamine that causes drowsiness and is used in sleep aids and allergy medications.
- Doxylamine
- A sedating antihistamine similar to diphenhydramine that helps promote sleep.
- CNS depression
- A slowing down of brain and nervous system activity that can cause drowsiness and reduced alertness.
- Anticholinergic effects
- Side effects that include dry mouth, dry eyes, constipation, and difficulty urinating due to blocked nerve signals.
- Respiratory depression
- A dangerous slowing of breathing rate that can occur when combining certain medications.
- Analgesic
- A medication that relieves pain.
- Cough suppressant
- A medication that reduces or stops coughing.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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