Bitter Orange - NyQuil (acetaminophen, dextromethorphan, doxylamine) Interaction
Herbal: Bitter Orange
Also Known As: Citrus aurantium, Aurantii Fructus, Aurantium, Bigarade, Chisil, Kijitsu, Marmalade Orange, Meta-Synephrine, Naranja Amarga, Neroli Oil, Norsynephrine, Octopamine, Orange Amère, Seville Orange, Shangzhou Zhiqiao, Sour Orange, Synephrine, Zhi Ke, Zhi Qiao, Zhi Shi
Drug: acetaminophen, dextromethorphan, doxylamine
Brand names:
NyQuil

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
acetaminophen, dextromethorphan, doxylamine is classified as belonging to the following category: Dextromethorphan (Robitussin Dm, Others)
Bitter orange might increase blood levels of dextromethorphan.
One small clinical study shows that bitter orange juice increases dextromethorphan levels, likely through cytochrome P450 3A4 (CYP3A4) inhibition. Theoretically, bitter orange might increase the risk for dextromethorphan-related adverse effects.
Interaction Rating
Likelihood of Occurrence
PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
References
- Di Marco MP, Edwards DJ, Wainer IW, Ducharme MP. The effect of grapefruit juice and seville orange juice on the pharmacokinetics of dextromethorphan: the role of gut CYP3A and P-glycoprotein. Life Sci 2002;71:1149-60.
Bitter Orange Overview

Bitter Orange - More Interactions
Bitter Orange interacts with 931 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.