Turpentine Oil - Vicks NyQuil (Acetaminophen, Dextromethorphan, Doxylamine, Pseudoephedrine) Interaction
Herbal: Turpentine Oil
Also Known As: Pinus palustris, Aceite de Trementina, Essence de Térébenthine, Huile de Pin, Huile de Térébenthine, Huile de Térébenthine Purifiée, Pine Oleoresin, Pine Tree Terpenic, Purified Turpentine Oil, Spirits of Turpentine, Térébenthine, Terebinthinae Aetheroleum
Drug: Acetaminophen, Dextromethorphan, Doxylamine, Pseudoephedrine
Brand names:
Vicks NyQuil

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Acetaminophen, Dextromethorphan, Doxylamine, Pseudoephedrine is classified as belonging to the following category: Cytochrome P450 1A2 (Cyp1A2) Substrates
There is some concern that turpentine oil can inhibit CYP1A2 enzyme activity by up to 90% via induction of inflammation and subsequent downregulation of CYP activity. However, animal research suggests that turpentine oil does not affect the metabolism of phenacetin, a CYP1A2 substrate, despite inducing inflammation.
Some medications metabolized by CYP1A2 include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, tizanidine (Zanaflex), zileuton (Zyflo), zolmitriptan (Zomig), and others.
Interaction Rating
Likelihood of Occurrence
UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
References
- Prasad VG, Vivek Ch, Anand Kumar P, Ravi Kumar P, Rao GS. Turpentine oil induced inflammation decreases absorption and increases distribution of phenacetin without altering its elimination process in rats. Eur J Drug Metab Pharmacokinet 2015;40(1):23-8.
Turpentine Oil Overview

Turpentine Oil - More Interactions
Turpentine Oil interacts with 362 drugs
Interaction Rating Key
These severity listings are for informational use only. Never start, stop or otherwise change your therapy before speaking with your provider.
Major | The combined use of these agents is strongly discouraged as serious side effects or other negative outcomes could occur. |
Moderate | Use cautiously under the care of a healthcare professional or avoid this combination. A significant interaction or negative outcome could occur. |
Minor | Be aware that there is a chance of an interaction. Watch for warning signs of a potential interaction. |
Unknown | No interactions have been reported or no interaction data is currently available. |
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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.
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Drug descriptions are provided by MedlinePlus.