Drug & supplement interaction

Ilex Guayusa + Doripenem

Doripenem brand name: Doribax.

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

Ilex Guayusa has a minor interaction with Doripenem. Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.

Read the full interaction report
SeverityMinor
LikelihoodPossible
EvidenceB
What do Severity, Likelihood & Evidence mean?
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Interaction report

Ilex Guayusa and Doripenem

Here is the interaction we found between these two, with the evidence behind it.

Minor

QUINOLONE ANTIBIOTICS

Why this applies to Doripenem

Doripenem falls under QUINOLONE ANTIBIOTICS — the group Ilex Guayusa interacts with.

Theoretically, quinolone antibiotics might increase the levels and adverse effects of caffeine.
Ilex guayusa contains caffeine. Concomitant use of quinolones can decrease caffeine clearance and increase effects and risk of adverse effects.
Severity Minor Likelihood Possible Evidence B

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 a small wrinkle worth knowing about. The interaction we have on file is really about quinolone antibiotics (like ciprofloxacin), which can slow down how your body clears caffeine. Doripenem (Doribax), though, is a different family of antibiotic called a carbapenem, not a quinolone. So this particular caffeine concern doesn't truly carry over to doripenem the same way.

The good news is doripenem isn't known to block caffeine breakdown, so your guayusa tea shouldn't pile up extra jitteriness, a racing heart, or trouble sleeping the way it might with a quinolone. Doripenem is also given as an IV in a hospital setting, where your care team is watching closely. Still, if you have heart concerns or feel unusually wired, mention it to your pharmacist or doctor so they can check in with you.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Harder S, Fuhr U, Staib AH, Wolff T. Ciprofloxacin-caffeine: a drug interaction established using in vivo and in vitro investigations. Am J Med 1989;87:89S-91S. PubMed
  2. Carbo M, Segura J, De la Torre R, et al. Effect of quinolones on caffeine disposition. Clin Pharmacol Ther 1989;45:234-40. PubMed
  3. Healy DP, Polk RE, Kanawati L, et al. Interaction between oral ciprofloxacin and caffeine in normal volunteers. Antimicrob Agents Chemother 1989;33:474-8. PubMed
  4. Staib, A. H., Stille, W., Dietlein, G., Shah, P. M., Harder, S., Mieke, S., and Beer, C. Interaction between quinolones and caffeine. Drugs 1987;34 Suppl 1:170-174. PubMed
  5. Stille, W., Harder, S., Mieke, S., Beer, C., Shah, P. M., Frech, K., and Staib, A. H. Decrease of caffeine elimination in man during co-administration of 4-quinolones. J.Antimicrob.Chemother. 1987;20(5):729-734. PubMed
  6. Fuhr, U., Strobl, G., Manaut, F., Anders, E. M., Sorgel, F., Lopez-de-Brinas, E., Chu, D. T., Pernet, A. G., Mahr, G., Sanz, F., and . Quinolone antibacterial agents: relationship between structure and in vitro inhibition of the human cytochrome P450 isof
  7. Harder S, Staib AH, Beer C, et al. 4-quinolones inhibit biotransformation of caffeine. Eur J Clin Pharmacol 1988;35:651-6. PubMed
  8. Zhang LL, Zhang JR, Guo K, et al. Effects of fluoroquinolones on CYP4501A and 3A in male broilers. Res Vet Sci 2011;90:99-105. PubMed
  9. Cesana M, Broccali G, Imbimbo BP, Crema A. Effect of single doses of rufloxacin on the disposition of theophylline and caffeine after single administration. Int J Clin Pharmacol Ther Toxicol 1991:29:133-8.

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

Ilex Guayusa Also Interacts With Other Medications

Ilex Guayusa has 8 major, 470 moderate, 126 minor known drug interactions in our database — the Doripenem one above is one of them. If you take anything else, check it against the full list below.

Major 8 Moderate 470 Minor 126 No known interaction 2,226 (incl. Doripenem)
Taking anything else?

Check Another of Your Medications Against Ilex Guayusa

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

Everything else you take

See Every Supplement That Interacts With Doripenem

This page covers Ilex Guayusa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Doripenem page lists 84 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Oleander (major), Para-aminobenzoic Acid (paba) (major), Acerola (moderate), Alpha-lipoic Acid (moderate) and Bacillus Coagulans (moderate).

By severity: 2 major · 75 moderate · 7 minor.

From our pharmacist’s overview on the Doripenem page

“Two entries here matter more than all the others, and I would read them first. Doripenem (Doribax) is an intravenous antibiotic reserved for serious bacterial infections, which means anything that weakens treatment or piles on risk deserves genuine caution.”

Reviewed by 2 · Jul 18, 2026

Open the Doripenem interaction page

How much people look this up

Where Ilex Guayusa and Doripenem 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 Ilex Guayusa
Steady interest

#1,156 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Doripenem
Steady interest

#1,538 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 Ilex Guayusa

What is Ilex Guayusa?

  • Energy and alertness
  • Mental focus
  • Antioxidant support
  • Appetite control
  • Athletic and physical performance

Ilex guayusa is a caffeine-containing holly leaf from the Amazon, traditionally brewed as a tea for energy and alertness, much like yerba mate or green tea. There is limited human research confirming specific health benefits, and its main reliable effect comes from its caffeine content. Because it is a stimulant, use it cautiously and check with your pharmacist or doctor if you have heart concerns or are pregnant.

Read the full Ilex Guayusa monograph & all interactions
Medication

About Doripenem Injection

What Is Doripenem Injection Used For?

Brand name: Doribax

  • Doripenem injection is used to treat serious infections of the urinary tract, kidney, and abdomen that are caused by bacteria. Doripenem injection is not approved by the Food and Drug Administration (FDA) to treat pneumonia that developed in people who were on a ventilator in a hospital. Doripenem injection is in a class of medications called carbapenem antibiotics. It works by killing bacteria.

  • Antibiotics such as doripenem injection will not work for colds, flu, or other viral infections. Taking antibiotics when they are not needed increases your risk of getting an infection later that resists antibiotic treatment.

See full Doripenem Injection drug information
Keep checking

Other Drugs & Ilex Guayusa

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

8Major
470Moderate
126Minor
2,225No known interaction
8 Major 470 Moderate 126 Minor 2,225 No interaction
Major

8 interactions

Moderate

470 interactions

Showing 60 of 470 moderate interactions — see all 470 on the Ilex Guayusa page.

Minor

126 interactions

Showing 60 of 126 minor interactions — see all 126 on the Ilex Guayusa page.

No interaction 2,225 drugs checked — show the list

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

Showing the 60 most looked-up of 2,225 medications checked with no known interaction — see the full Ilex Guayusa list.

See the full Ilex Guayusa interactions page
See every supplement checked against Doripenem, 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
Ilex Guayusa monograph › Uses, safety, and every drug interaction in one place Doripenem supplement interactions › Every supplement checked against Doripenem, ranked by severity Doripenem Injection drug information › The full plain-English guide to this medication 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 Ilex Guayusa and Doripenem Together: Common Questions

Can you take Ilex Guayusa with Doripenem?
There is only a minor interaction, which is usually not serious. Read the full details on this page and confirm with your pharmacist before combining them.
How serious is the Ilex Guayusa and Doripenem interaction?
We rate it Minor. This interaction is generally not clinically significant, but it remains worth noting and discussing with your pharmacist.

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

Still Have a Question About Doripenem and Ilex Guayusa?

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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.