There is no interaction between benzonatate and NyQuil. They are generally considered to be safe to take together.


However, NyQuil will cause sedation about 30 to 60 minutes after taking by mouth and benzonatate may cause mild sedation in some individuals. Therefore, there is a chance of additive sedative effects with the two medications.


Benzonatate Information

Benzonatate (brand name Tessalon) is a non-narcotic medication, most commonly used for cough symptoms associated with colds and acute respiratory infections. At normal dosages, benzonatate is not associated with respiratory depression or significant CNS (central nervous system) depression and is therefore considered safe to take with most other medications.


Benzonatate works by anesthetizing the stretch receptors in the alveoli of the lungs and airways. This reduces the sensation of needing to cough.


While benzonatate is typically very well tolerated, it can cause mild sedation. When combined with other medications that cause sedation, such as NyQuil, the sedative effects can be enhanced and you should not operate heavy machinery or partake in activities that require strict attention. 


NyQuil Information

NyQuil is a combination cough/cold medication that contains the following ingredients:

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


While NyQuil does contain a cough suppressant (dextromethorphan), it is not thought to interact with benzonatate.


Doxylamine, the sedating antihistamine in NyQuil, could potentially cause additive effects of sedation with given with benzonatate. Doxylamine begins to work in about 30 minutes but peak concentrations in the blood occur nearly 2 to 3 hours after taking by mouth. This means that while you will feel the effects of doxylamine relatively quickly, it can take a few hours for the drug to reach max effect.


Taking Benzonatate With NyQuil

As mentioned above, there is no interaction between benzonatate and NyQuil. However, NyQuil will almost assuredly cause sedition and benzonatate may have mild sedative effects as well. Therefore, although there is no drug-drug interaction between the two, caution is advised when using the combination due to the additive sedative effects.