Green Tea - Clozaril (Clozapine) Interaction
Herbal: Green Tea
Also Known As: Camellia sinensis, Green Sencha Tea, Green Tea Extract, GTP, GTPF, Japanese Sencha Green Tea, Japanese Tea, Kunecatechins, Poly E, Polyphenon E, PTV, Té Verde, Tea Extract, Tea Green, Tea, Thé, Thé Vert, Yabukita, Yame Green Tea, Yame Tea
Drug: Clozapine
Brand names:
Clozaril, Versacloz
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Jun 16, 2024
Interaction Details
Clozapine is classified as belonging to the following category: Clozapine (Clozaril)
Theoretically, green tea might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Animal research suggests that, although green tea extract does not affect the elimination of clozapine, it delays the time to reach peak concentration and reduces the peak plasma levels. Also, concomitant administration of green tea and clozapine might theoretically cause acute exacerbation of psychotic symptoms due to the caffeine in green tea. Caffeine can increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg daily inhibit clozapine metabolism. Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Researchers speculate that caffeine might inhibit CYP1A2. However, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients be more sensitive to the interaction between clozapine and caffeine.
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
- Hagg S, Spigset O, Mjorndal T, Dahlqvist R. Effect of caffeine on clozapine pharmacokinetics in healthy volunteers. Br J Clin Pharmacol 2000;49:59-63.
- Raaska K, Raitasuo V, Laitila J, Neuvonen PJ. Effect of caffeine-containing versus decaffeinated coffee on serum clozapine concentrations in hospitalised patients. Basic Clin Pharmacol Toxicol 2004;94:13-8.
- Jang EH, Choi JY, Park CS, Lee SK, Kim CE, Park HJ, Kang JS, Lee JW, Kang JH. Effects of green tea extract administration on the pharmacokinetics of clozapine in rats. J Pharm Pharmacol. 2005 Mar;57(3):311-6.
Green Tea Overview
Green tea is a type of tea that is made from the leaves of the Camellia sinensis plant. It is native to Asia and is widely consumed throughout the world. Green tea has a mild, slightly grassy flavor and is typically lighter in color and less astringent than black tea.
Green tea is a rich source of antioxidants, particularly a group of compounds called catechins. These antioxidants are thought to help protect cells from damage caused by free radicals. Green tea is also a good source of other nutrients, including vitamin C and several B vitamins.
Green tea is often consumed for a number of purported health benefits including reducing the risk of heart disease, immune-stimulating effects, and weight loss.
Oral green tea supplements, containing dried powder, are most often utilized for the caffeine content and used as an appetite suppressant for weight loss.
Clozapine Overview
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Clozapine is used to treat the symptoms of schizophrenia (a mental illness that causes disturbed or unusual thinking, loss of interest in life, and strong or inappropriate emotions) in people who have not been helped by other medications or who have tried to kill themselves and are likely to try to kill or harm themselves again. Clozapine is in a class of medications called atypical antipsychotics. It works by changing the activity of certain natural substances in the brain.
Green Tea - More Interactions
Green Tea interacts with 1206 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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