St. John's Wort - Ephedrine, Phenobarbital, Theophylline Interaction
Herbal: St. John's Wort
Also Known As: Hypericum perforatum, Amber Touch-and-Heal, Barbe de Saint-Jean, Chasse-diable, Demon Chaser, Fuga Daemonum, Hardhay, Herbe Aux Mille Vertus, Hypereikon, Hyperici Herba, Hypericum, Millepertuis, Perforate St. John's Wort, Racecourse Weed, Rosin Rose, Saynt Johannes Wort
Drug: Ephedrine, Phenobarbital, Theophylline
Brand names:
Tedral
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jul 22, 2023
Interaction Details
Ephedrine, Phenobarbital, Theophylline is classified as belonging to the following category: Theophylline
St. John's wort might decrease the levels of theophylline, although this effect might not be clinically relevant.
St. John's wort does not seem to significantly affect theophylline pharmacokinetics. There is a single case report of a possible interaction with theophylline. A patient who smoked and was taking 11 other drugs experienced an increase in theophylline levels after discontinuation of St. John's wort. This increase has been attributed to a rebounding of theophylline serum levels after St. John's wort was no longer present to induce metabolism via cytochrome P450 1A2 (CYP1A2). However, studies in healthy volunteers show that St. John's wort is unlikely to affect theophylline to any clinically significant degree.
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
- Nebel A, Schneider BJ, Baker RA, et al. Potential metabolic interaction between St. John's wort and theophylline. Ann Pharmacother 1999;33:502.
- Schulz V. Incidence and clinical relevance of the interactions and side effects of Hypericum preparations. Phytomedicine 2001;8:152-60.
- Henderson L, Yue QY, Bergquist C, et al. St John's wort (Hypericum perforatum): drug interactions and clinical outcomes. Br J Clin Pharmacol 2002;54:349-56..
- Morimoto T, Kotegawa T, Tsutsumi K, et al. Effect of St. John's wort on the pharmacokinetics of theophylline in healthy volunteers. J Clin Pharmacol 2004;44:95-101.
Interaction Details
Ephedrine, Phenobarbital, Theophylline is classified as belonging to the following category: Phenobarbital (Luminal)
St. John's wort decreases the levels and clinical effects of phenobarbital.
St. John's wort may increase the metabolism of phenobarbital. Plasma concentrations of phenobarbital should be monitored carefully. The dose of phenobarbital may need to be increased when St. John's wort is started and decreased when it is stopped.
Interaction Rating
Likelihood of Occurrence
LikelyWell-controlled human studies have demonstrated the likely existence of this interaction
References
- Henderson L, Yue QY, Bergquist C, et al. St John's wort (Hypericum perforatum): drug interactions and clinical outcomes. Br J Clin Pharmacol 2002;54:349-56..
St. John's Wort Overview
St. John's wort (Hypericum perforatum) is a plant native to Europe and is known for its medicinal properties. St. John's wort has been used to treat a variety of conditions, including depression, anxiety, and sleep disorders. It is one of the most extensively used and researched natural medicines in the world, and is thought to work similarly to certain conventional antidepressants by increasing the levels of serotonin in the brain.
St. John's Wort - More Interactions
St. John's Wort interacts with 1098 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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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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