Interaction Details

Aspirin, Butalbital, Caffeine, Codeine Phosphate is classified as belonging to the following category: Anticoagulant/Antiplatelet Drugs

Theoretically, arnica might have additive effects with anticoagulant and antiplatelet drugs. Homeopathic arnica preparations are unlikely to have this interaction.
In vitro evidence shows that sesquiterpene lactones in arnica flowers can decrease platelet aggregation. However, this effect has not been reported in humans.

Interaction Rating


Likelihood of Occurrence


Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.


  • Schroder H, Losche W, Strobach H, et al. Helenalin and 11 alpha, 13-dihydrohelenalin, two constituents from Arnica montana L., inhibit human platelet function via thiol-dependent pathways. Thromb Res 1990;57:839-45.

Arnica Overview

Arnica Arnica is a plant that is native to Europe and North America and is part of the daisy family. It is known for its yellow, daisy-like flowers and has been traditionally used in homeopathic medicine to help decrease pain, swelling, and bruising. It has also been used in topical preparations to help reduce the pain from osteoarthritis. Arnica preparations are typically standardized according to the Homeopathic Pharmacopeia of the United States. In terms of drug interactions, it is important to note that in theory, arnica might have additive effects with anticoagulant and antiplatelet drugs but homeopathic arnica preparations are unlikely to have this interaction due to the extremely low amounts used.
See More Information Regarding Arnica

Arnica - More Interactions

Arnica interacts with 120 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.

© 2021 Therapeutic Research Center, LLC

Drug descriptions are provided by MedlinePlus.

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