Fever Bark - Aspirin, Codeine Phosphate, Methocarbamol Interaction
Herbal: Fever Bark
Also Known As: Alstonia constricta, Alstonia Bark, Australian Febrifuge, Australian Fever Bush, Australian Quinine, Bitterbark, Corteza de Alstonia, Devil Tree, Devil's Bit, Dita Bark, Écorce Amère d'Australie, Écorce de Quinquina, Écorce de Quinquina d'Australie
Drug: Aspirin, Codeine Phosphate, Methocarbamol
Brand names:
Robaxisal C
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
May 04, 2025
Interaction Details
Aspirin, Codeine Phosphate, Methocarbamol is classified as belonging to the following category: Cytochrome P450 2D6 (Cyp2D6) Substrates
Theoretically, fever bark might increase the levels and clinical effects of CYP2D6 substrates.
In vitro research suggests that yohimbine, a constituent of fever bark, inhibits CYP2D6 enzyme activity. The effects of fever bark itself are unclear.
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
- VandenBrink, B. M., Foti, R. S., Rock, D. A., Wienkers, L. C., and Wahlstrom, J. L. Prediction of CYP2D6 drug interactions from in vitro data: evidence for substrate-dependent inhibition. Drug Metab Dispos. 2012;40(1):47-53.
Interaction Details
Aspirin, Codeine Phosphate, Methocarbamol is classified as belonging to the following category: Anticoagulant/Antiplatelet Drugs
Theoretically, combining fever bark with antiplatelet or anticoagulant drugs might have additive effects; however, this has not been reported in clinical research.
Research in healthy adults shows that taking yohimbine, a constituent of fever bark, in doses of 8 mg or more, seems to inhibit platelet aggregation in vitro by binding to the alpha-2 adrenoceptor. The effects of fever bark itself are unclear.
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
- Mustonen, P., Savola, J., and Lassila, R. Atipamezole, an imidazoline-type alpha(2)-adrenoceptor inhibitor, binds to human platelets and inhibits their adrenaline-induced aggregation more effectively than yohimbine. Thromb.Res 8-1-2000;99(3):231-237.
- Berlin, I., Crespo-Laumonnier, B., Cournot, A., Landault, C., Aubin, F., Legrand, J. C., and Puech, A. J. The alpha 2-adrenergic receptor antagonist yohimbine inhibits epinephrine-induced platelet aggregation in healthy subjects. Clin Pharmacol.Ther. 199
- Braddock, L., Cowen, P. J., Elliott, J. M., Fraser, S., and Stump, K. Binding of yohimbine and imipramine to platelets in depressive illness. Psychol.Med 1986;16(4):765-773.
- Boon, N. A., Elliott, J. M., Grahame-Smith, D. G., John-Green, T., and Stump, K. A comparison of alpha 2-adrenoreceptor binding characteristics of intact human platelets identified by [3H]-yohimbine and [3H]- dihydroergocryptine. J Auton.Pharmacol 1983;3
Fever Bark Overview
Fever bark is the bark of the evergreen tree Alstonia constricta. The tree is native to tropical regions of Asia and is known for its tall, straight trunk and glossy, dark green leaves.
Alstonia constricta is used in traditional medicine to treat a variety of ailments, including fever, diarrhea, and infections. The bark of the tree contains several different alkaloids, including reserpine and yohimbine, which could cause serious side effects if misused. Unless you are under the direct supervision of a medical professional, the use of fever bark is not recommended.
Fever bark is sometimes referred to as Australian quinine, but it is not known to contain quinine.
Fever Bark - More Interactions
Fever Bark interacts with 790 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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Parts of this content are provided by the Therapeutic Research Center, LLC.
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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Dr. Brian Staiger, PharmD
In addition to being a clinical pharmacist specializing in pharmacotherapy, Dr. Brian Staiger is a registered herbalist through the American Herbalist Guild. He has combined his passion for pharmacy practice with the study of medical ethnobotany to improve patient care. Feel free to reach out about any of your herbal or medication questions!
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