Drug & supplement interaction

Green Tea + Olodaterol Hydrochloride, Tiotropium Bromide

Olodaterol Hydrochloride, Tiotropium Bromide brand name: Stiolto Respimat.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Olodaterol Hydrochloride, Tiotropium Bromide falls into 3 drug categories that Green Tea can interact with; the most serious is rated moderate. Green tea might increase the levels and adverse effects of P-glycoprotein (P-gp) substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Green Tea and Olodaterol Hydrochloride, Tiotropium Bromide

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Green Tea interacts with whole categories of medication. Olodaterol Hydrochloride, Tiotropium Bromide falls into 3 of those categories, so it can interact with Green Tea in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

P-GLYCOPROTEIN SUBSTRATES

1 of 3

Why this applies to Olodaterol Hydrochloride, Tiotropium Bromide

Olodaterol Hydrochloride, Tiotropium Bromide falls under P-GLYCOPROTEIN SUBSTRATES — the group Green Tea interacts with.

Green tea might increase the levels and adverse effects of P-glycoprotein (P-gp) substrates.
In vitro research and case reports suggest that green tea inhibits drug efflux by P-gp, potentially increasing serum levels of P-gp substrates. Case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking green tea and certain P-gp substrates.
Severity Moderate Likelihood Possible Evidence D

Interaction 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.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist with Stiolto Respimat (olodaterol and tiotropium). Tiotropium is moved around your body partly by a transporter called P-glycoprotein, which acts like a bouncer that pushes drug out of cells. Green tea may slow that bouncer down a little, so in theory a bit more tiotropium could hang around. If that happens, you might notice the usual anticholinergic effects more, things like dry mouth, blurry vision, constipation, or trouble urinating.

The good news: this is based on very weak, anecdotal evidence, and a normal cup or two of green tea is unlikely to cause trouble. Concentrated green tea extract pills are where I'd be more cautious. Since this is an inhaled medicine with low blood levels, the risk is small, but it's worth a quick chat with your pharmacist if you take green tea supplements regularly.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Pochet S, Lechon AS, Lescrainier C, et al. Herb-anticancer drug interactions in real life based on VigiBase, the WHO global database. Sci Rep 2022;12(1):14178. PubMed
Moderate

BETA-ADRENERGIC AGONISTS

2 of 3

Olodaterol Hydrochloride, Tiotropium Bromide also falls under BETA-ADRENERGIC AGONISTS.

Green tea contains caffeine. Theoretically, concomitant use of large amounts of caffeine might increase cardiac inotropic effects of beta-agonists.
Severity Moderate Likelihood Probable Evidence D

Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports..

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the deal with Stiolto Respimat: one of its two ingredients, olodaterol, is a long-acting beta-agonist that opens up your airways. The caffeine in green tea is a mild stimulant, and on paper combining a lot of caffeine with a beta-agonist could nudge your heart a little harder, possibly leaving you feeling jittery, with a faster heartbeat or some heart pounding (palpitations).

The important word here is theoretical. This concern is based on how these compounds work, not on strong studies, and it's tied to large amounts of caffeine. A cup or two of green tea is very unlikely to cause trouble. Concentrated green tea extract pills are a different matter. If you notice your heart racing or feel shaky, mention it to your pharmacist or doctor.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
Minor

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

3 of 3

Olodaterol Hydrochloride, Tiotropium Bromide also falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES.

Green tea is unlikely to produce clinically significant changes in the levels and clinical effects of CYP3A4 substrates.
In vitro and in vivo research suggests that green tea can inhibit intestinal CYP3A and induce hepatic CYP3A4 enzymes. However, this effect is unlikely to be clinically significant, as green tea does not appear to affect CYP3A4 activity in humans.
Severity Minor Likelihood Unlikely Evidence D

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

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Good news here: if you enjoy a cup or two of green tea while using your Stiolto Respimat inhaler, there's very little to worry about. One of the ingredients, olodaterol, is partly processed by a liver enzyme called CYP3A4. In the lab, green tea has shown some mixed effects on this enzyme, but in actual people it doesn't seem to meaningfully change how the drug behaves.

This concern is mostly theoretical and rests on test-tube and animal studies, so I wouldn't lose sleep over your morning tea. Even in the rare case levels nudged up, you'd watch for things like a faster heartbeat, jitteriness, or a dry mouth. If you're thinking about concentrated green tea extract pills rather than the beverage, just run that by your pharmacist first.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Donovan JL, Chavin KD, Devane CL, et al. Green tea (Camellia sinensis) extract does not alter cytochrome P450 3A4 or 2D6 activity in healthy volunteers. Drug Metab Dispos 2004;32:906-8. PubMed
  2. Nishikawa, M., Ariyoshi, N., Kotani, A., Ishii, I., Nakamura, H., Nakasa, H., Ida, M., Nakamura, H., Kimura, N., Kimura, M., Hasegawa, A., Kusu, F., Ohmori, S., Nakazawa, K., and Kitada, M. Effects of continuous ingestion of green tea or grape seed extrac
  3. Chow, H. H., Hakim, I. A., Vining, D. R., Crowell, J. A., Cordova, C. A., Chew, W. M., Xu, M. J., Hsu, C. H., Ranger-Moore, J., and Alberts, D. S. Effects of repeated green tea catechin administration on human cytochrome P450 activity. Cancer Epidemiol.B PubMed
  4. Engdal, S. and Nilsen, O. G. In vitro inhibition of CYP3A4 by herbal remedies frequently used by cancer patients. Phytother.Res. 2009;23(7):906-912.
  5. Schönthal AH. Adverse effects of concentrated green tea extracts. Mol Nutr Food Res. 2011 Jun;55(6):874-85. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • 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.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Green Tea Also Interacts With Other Medications

Green Tea has 13 major, 904 moderate, 375 minor known drug interactions in our database — the Olodaterol Hydrochloride, Tiotropium Bromide one above is among them. If you take anything else, check it against the full list below.

Major 13 Moderate 904 Minor 375 No known interaction 1,538 (incl. Olodaterol Hydrochloride, Tiotropium Bromide)
Taking anything else?

Check Another of Your Medications Against Green Tea

Covers the 2,830 medications we’ve checked against Green Tea. Pick one to open its full report.

From our Q&A

Questions About Green Tea or Olodaterol Hydrochloride, Tiotropium Bromide

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Green Tea or Olodaterol Hydrochloride, Tiotropium Bromide, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Olodaterol Hydrochloride, Tiotropium Bromide

This page covers Green Tea only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Olodaterol Hydrochloride, Tiotropium Bromide page lists 171 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: American Hellebore (major), Arsenic (major), Cesium (major), Ephedra (major) and Grapefruit (major).

By severity: 9 major · 133 moderate · 29 minor.

Open the Olodaterol Hydrochloride, Tiotropium Bromide interaction page

One more smart check

Taking Green Tea as Part of a Dietary Supplement Product? Check It for Interactions

We hold 9,084 real supplement products containing Green Tea, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Green Tea. Your product may carry other ingredients that interact with Olodaterol Hydrochloride, Tiotropium Bromide too, on top of Green Tea — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Green Tea and Olodaterol Hydrochloride, Tiotropium Bromide Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Green Tea
Top 5%

#23 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Olodaterol Hydrochloride, Tiotropium Bromide
Top 5%

#105 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Green Tea

What is Green Tea?

Green Tea
  • Antioxidant support
  • Weight loss
  • Heart health
  • Mental alertness
  • Cancer risk reduction

Green tea is a popular beverage rich in antioxidants called catechins, and drinking it in normal amounts is considered safe for most people. Concentrated green tea extracts are a different story—they may help modestly with weight or heart health for some, but high doses have been linked to rare liver problems. Talk to your pharmacist or doctor before taking green tea supplements, especially if you have liver concerns or are pregnant.

Read the full Green Tea monograph & all interactions
Keep checking

Other Drugs & Green Tea

Browse every other medication we’ve checked against Green Tea — both the ones with a known interaction and the ones without. Select any drug for the full detail.

13Major
904Moderate
375Minor
1,537No known interaction
13 Major 904 Moderate 375 Minor 1,537 No interaction
Major

13 interactions

Moderate

904 interactions

Showing 60 of 904 moderate interactions — see all 904 on the Green Tea page.

Minor

375 interactions

Showing 60 of 375 minor interactions — see all 375 on the Green Tea page.

No interaction 1,537 drugs checked — show the list

We also checked Green Tea against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 1,537 medications checked with no known interaction — see the full Green Tea list.

See the full Green Tea interactions page
See every supplement checked against Olodaterol Hydrochloride, Tiotropium Bromide, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

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

Keep exploring
Green Tea monograph › Uses, safety, and every drug interaction in one place Olodaterol Hydrochloride, Tiotropium Bromide supplement interactions › Every supplement checked against Olodaterol Hydrochloride, Tiotropium Bromide, ranked by severity Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Green Tea and Olodaterol Hydrochloride, Tiotropium Bromide Together: Common Questions

Can you take Green Tea with Olodaterol Hydrochloride, Tiotropium Bromide?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 3 interactions listed for Green Tea and Olodaterol Hydrochloride, Tiotropium Bromide?
Olodaterol Hydrochloride, Tiotropium Bromide belongs to more than one drug category, and Green Tea interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Green Tea and Olodaterol Hydrochloride, Tiotropium Bromide interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Still Have a Question About Olodaterol Hydrochloride, Tiotropium Bromide and Green Tea?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.