The short answer
Ordinary tea and concentrated green tea extracts need different assessments during zileuton treatment. A specific harmful tea-zileuton interaction has not been established.
What this answer covers
Camellia sinensis; beverage, concentrated extract and caffeine content distinguished. The inventory does not specify a standardized extract.
- Supplement or preparation
- Camellia sinensis
- Medication ingredient
- zileuton
Identify tea versus extract
Brewed tea and concentrated capsules can deliver very different constituents. NCCIH distinguishes adult beverage use from extract products, which have uncommon liver injury reports.
Why extracts deserve review
Zileuton itself requires liver monitoring. A concentrated green tea supplement adds an independent possible liver concern, so have it reviewed before starting. This does not prove the combination increases injury by a known amount.
Caffeine is a separate question
Tea may contribute to caffeine intake. The established zileuton-theophylline interaction does not directly measure caffeine exposure from tea, and no exact tea combination study was identified.
Keep the correct asthma regimen
Zileuton is for ongoing asthma control and does not treat a sudden attack. Follow the instructions for your immediate-release or extended-release product, including its food directions. Do not change the dose to compensate for a supplement.
Continue liver monitoring
Keep the liver blood tests arranged by your prescriber. Promptly report yellow skin or eyes, dark urine, unusual fatigue, nausea or pain in the upper right abdomen. A supplement does not replace the monitoring required during zileuton treatment.
Evidence and practical considerations
Side effects & toxicity
The broad Camellia sinensis increased-risk claim is insufficient. Conditional concern is reasonable for concentrated extracts with independent liver injury signals and for substantial caffeine exposure, but no exact combined outcome is demonstrated.
- Exact scope
- Camellia sinensis; beverage, concentrated extract and caffeine content distinguished. The inventory does not specify a standardized extract. with Exact zileuton immediate-release and extended-release oral tablets. Exact RxNorm IN40575. Immediate-release and extended-release tablets have different dosing and food instructions; neither is an acute rescue bronchodilator.
- Medication form and route
- oral
- Timing or duration
- Source-specific single-dose, repeated-dose and observational exposures distinguished.
What remains uncertain
- Do not transfer extract liver findings to routine brewed tea or theophylline PK to tea caffeine; no universal dose or timing rule.
Factors that may matter: preparation and plant part; clinical indication; dose; other medicines; baseline alertness.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed zileuton.
Liver injury precautions and scheduled ALT monitoring; original theophylline interaction study shows reduced clearance, not direct caffeine evidence. CYP1A2, CYP2C9 and CYP3A4 contribute to in vitro metabolism.
How this applies: Exact RxNorm IN40575. Immediate-release and extended-release tablets have different dosing and food instructions; neither is an acute rescue bronchodilator.
No universal supplement dose, interval, event rate or untested formulation equivalence.
Source 2: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed zileuton.
Liver injury precautions and scheduled ALT monitoring; original theophylline interaction study shows reduced clearance, not direct caffeine evidence. CYP1A2, CYP2C9 and CYP3A4 contribute to in vitro metabolism.
How this applies: Exact RxNorm IN40575. Immediate-release and extended-release tablets have different dosing and food instructions; neither is an acute rescue bronchodilator.
No universal supplement dose, interval, event rate or untested formulation equivalence.
Source 3: official supplement guidance
nccih.nih.gov · Source check Sep 10, 2026
Population: People considering the specified supplement.
Tea contains caffeine; concentrated extracts differ from beverages and have been linked to uncommon liver injury and increased blood pressure.
How this applies: Supplement-only context; explicit medication and preparation bridge required.
Does not establish a respiratory medication interaction or identical caffeine content across extracts.
Source 4: official supplement guidance
fda.gov · Source check Sep 10, 2026
Population: People considering the specified supplement.
Caffeine can cause palpitations, anxiety, sleep problems and other effects; sensitivity depends partly on medicines and individual factors.
How this applies: Supplement-only context; explicit medication and preparation bridge required.
General adult intake advice does not establish a safe caffeine limit with this medicine.
Source 5: original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Sixteen healthy men in placebo-controlled crossover.
Theophylline clearance fell and concentrations rose; adverse events were more frequent with zileuton co-use.
How this applies: Only the named drug, preparation, route and measured endpoints apply.
A direct drug-drug study, not caffeine, tea, guarana or cola seed; cannot transfer measured changes to another methylxanthine.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Current exact available claims adjudicated using original captures and explicit identity and comparator limits. |
Article revision: b2b52a24d4257f5e
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.