Combining DayQuil & NyQuil For Nighttime Use

Answer

Both NyQuil and DayQuil share common ingredients so caution is advised when combining doses (to avoid overdose). However, one-half doses of each would be considered safe as you aren't going over the maximum dosage of any of the ingredients. You just need to be very careful to measure doses of each accurately.

Normally, you don't want to combine medications that share common ingredients. In fact, this is the way that most accidental overdoses occur.

For example, the number one reason for Tylenol (acetaminophen) overdoses is unknowingly combining two or more products that contain the drug.

However, as mentioned, since you are only taking half-doses of DayQuil and NyQuil, you are still in a safe dosage range for all the included medications.

Drugs In NyQuil & DayQuil

DayQuil contains the following ingredients:

• Acetaminophen (pain reliever)
• Dextromethorphan (cough suppressant)
• Phenylephrine (nasal decongestant)

NyQuil contains the following ingredients:

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

As seen above, both products contain acetaminophen and dextromethorphan.

Full doses of NyQuil and DayQuil should not be taken together to avoid overdosing. Half-doses will keep you in a safe range.

Differences Between DayQuil And NyQuil

Below, are the main differences between DayQuil and NyQuil:

• Phenylephrine (contained in DayQuil but not NyQuil)
• Doxylamine (contained in NyQuil but not DayQuil)
• Alcohol (NyQuil contains 10%, DayQuil is alcohol-free)

Phenylephrine is the nasal decongestant contained in DayQuil. It is not contained in NyQuil as it can cause insomnia or alertness in some individuals. Doxylamine is the antihistamine in NyQuil. It is added due to its sedative effect.

Combining DayQuil & NyQuil For Nighttime Use

While you could certainly combine DayQuil and NyQuil before bedtime (at appropriate dosages), it may not be as effective for sleep as NyQuil alone since DayQuil contains phenylephrine (nasal decongestant) and can cause insomnia in some people.

However, taking one-half dose of each will not result in too high of a dose of any single ingredient.  It is important to not take a full dose (30 ml) of each as this will result in a potential overdose of ingredients.

Taking half-doses (15 ml) of DayQuil and NyQuil will result in the following doses of each drug:

• Acetaminophen 625 mg (325 mg from each)

• Dextromethorphan 25 mg (15 mg from NyQuil, 10 mg from DayQuil)

• Phenylephrine 5 mg (from DayQuil)

• Doxylamine 6.25 mg (From NyQuil)

All the above doses are within the range of an acceptable single dose of each ingredient.

Final Words

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