Drug & supplement interaction

Buchu + Lapatinib

Lapatinib brand name: Tykerb.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between Buchu and Lapatinib in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Buchu and Lapatinib

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Lapatinib and Buchu in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Buchu safety at a glance

Buchu overall Use caution Generally used in food amounts, but medicinal doses lack strong safety data and the essential oil may be irritating.
Pregnancy Likely Unsafe When used in medicinal amounts; buchu is reported to be an abortifacient. Read the full pregnancy detail
Breastfeeding Possibly Safe When used in food amounts. There is insufficient reliable information available about the safety of using larger amounts; avoid using. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Lapatinib and Buchu? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Lapatinib

Interactions in our licensed database are recorded against drug classes, not just single drug names. Lapatinib is filed under 3 classifications — cytochrome p450 3a4 (cyp3a4) inhibitors, cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. Buchu has documented interactions with 3 drug classes — the most serious being anticoagulant/antiplatelet drugs (moderate), hepatotoxic drugs (moderate) and lithium (moderate) — and none of Lapatinib’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Buchu Does Interact With Other Medications

Buchu has 481 moderate known drug interactions in our database — Lapatinib isn’t one of them. If you take anything else, check it against the full list below.

Moderate 481 No known interaction 2,349 (incl. Lapatinib)
Taking anything else?

Check Another of Your Medications Against Buchu

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

What to actually watch for

What Lapatinib’s Own FDA Label Lists

This is not an interaction — none of it involves Buchu. These are the most notable effects listed in the ADVERSE REACTIONS section of Lapatinib’s own FDA label, for the medication by itself. Knowing the drug’s own list makes it easier to work out the likely cause if something new turns up while you take both.

  • Diarrhea mentioned in 27.1% of FDA reports for Lapatinib
  • Acne
  • Mouth irritation or sores
  • Tiredness mentioned in 8.5% of FDA reports for Lapatinib
  • Vomiting mentioned in 7.8% of FDA reports for Lapatinib
  • A skin rash mentioned in 6.9% of FDA reports for Lapatinib
  • Nausea mentioned in 10.5% of FDA reports for Lapatinib

From the ADVERSE REACTIONS section of the FDA label for Lapatinib. Read the label on DailyMed › Where a percentage is shown, it is the share of 15,427 voluntary FDA FAERS reports for Lapatinib that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Buchu’s licensed record lists no adverse effects our clinical vocabulary could match, so there is no Buchu side to compare — that is a limit of the record, not a statement that Buchu has no side effects.

Special populations

Buchu in Pregnancy & Breastfeeding

Pregnancy Likely Unsafe

When used in medicinal amounts; buchu is reported to be an abortifacient.

Lactation Possibly Safe

When used in food amounts. There is insufficient reliable information available about the safety of using larger amounts; avoid using.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Everything else you take

See Every Supplement That Interacts With Lapatinib

This page covers Buchu only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lapatinib page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 100 moderate · 40 minor.

From our pharmacist’s overview on the Lapatinib page

“Of the 143 supplements on file for lapatinib (Tykerb), nearly all press on the same point, the CYP3A4 enzyme that clears this HER2-targeted breast cancer drug. That deserves real caution, since lapatinib only works when its blood level stays in range.”

Reviewed by 2 · Jul 18, 2026

Open the Lapatinib interaction page

One more smart check

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

We hold 128 real supplement products containing Buchu, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Buchu. Even though Buchu itself has no known interaction with Lapatinib, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Buchu and Lapatinib 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 Buchu
Top 25%

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

29 days ago today
Medication Lapatinib
Steady interest

#1,678 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.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Buchu reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Buchu and Lapatinib records this page draws on were last updated July 11, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Buchu

What is Buchu?

Buchu
  • Urinary tract complaints
  • Diuretic (increasing urine flow)
  • Bloating and fluid retention
  • Mild digestive upset
  • Antimicrobial/antiseptic use
  • Flavoring and fragrance

Buchu is a fragrant South African shrub whose leaves are traditionally used for urinary and bladder complaints and as a diuretic. Solid human studies are lacking, so its benefits are largely unproven, and it should be avoided in pregnancy and breastfeeding. Talk to a pharmacist or doctor before using it, especially if you have kidney or liver problems.

Agathosma betulina · Rutaceae · Leaves and essential oil · Tea, capsules, tincture, dried leaf, essential oil

An interaction check asks whether these two react with each other — it does not ask whether Buchu is a good idea for someone in your situation. Here is what our Buchu record says about it on its own.

Buchu: dosing

There is no well-established standardized dose for buchu. Traditional preparations include teas made from the dried leaf and tinctures, but reliable human studies have not confirmed a safe and effective amount.If you choose to use a buchu product, follow the directions on the label and do not exceed them. Avoid taking the concentrated essential oil internally.

From our Buchu monograph — the full record covers uses, side effects and every documented interaction.

Read the full Buchu monograph & all interactions
Medication

About Lapatinib

What Is Lapatinib Used For?

Brand name: Tykerb

Lapatinib tablets — sold under the brand name Tykerb — are used to treat advanced or metastatic breast cancer in patients whose tumors overexpress the HER2 protein. They are always used in combination with another medicine, not alone.

Tykerb is approved in combination with capecitabine for HER2-positive advanced or metastatic breast cancer in patients who have already received prior treatment including an anthracycline, a taxane, and trastuzumab, and whose disease has progressed on trastuzumab. Tykerb is also approved in combination with letrozole for postmenopausal women with hormone receptor-positive, HER2-positive metastatic breast cancer when hormonal therapy is appropriate.

Most-Reported Side Effects for Lapatinib

From FAERS, the FDA’s public side-effect reporting system (15,427 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 4,174 reports
Nausea 1,615 reports
Fatigue 1,305 reports
Vomiting 1,209 reports
Rash 1,061 reports
See full Lapatinib drug information
Keep checking

Other Drugs & Buchu

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

0Major
481Moderate
0Minor
2,348No known interaction
481 Moderate 2,348 No interaction
Moderate

481 interactions

Showing 60 of 481 moderate interactions — see all 481 on the Buchu page.

No interaction 2,348 drugs checked — show the list

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

Showing the 60 most looked-up of 2,348 medications checked with no known interaction — see the full Buchu list.

See the full Buchu interactions page
See every supplement checked against Lapatinib, ranked by severity
Evidence & sources

Buchu References

The 3 references that drive our Buchu monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  2. Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
  3. Moolla A, Viljoen AM. 'Buchu' - Agathosma betulina and Agathosma crenulata (Retaceae): a review. J Ethnopharmacol 2008;119(3):413-9.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Buchu and Lapatinib Together: Common Questions

Is it safe to take Buchu with Lapatinib?
We do not list a known interaction between Buchu and Lapatinib. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
How was the Buchu and Lapatinib combination checked?
Interactions in our licensed database are recorded against drug classes. Lapatinib is filed under 3 classifications, and Buchu has documented interactions with 3 drug classes — none of Lapatinib's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Buchu interact with any other medications?
Yes. Buchu has 481 documented drug interactions in our database — Lapatinib is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Lapatinib interact with any supplements?
Yes. Lapatinib has documented interactions with 143 supplements in our database — Buchu is not one of them. The Lapatinib interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Buchu monograph Uses, safety profile, and every drug interaction in one place Lapatinib drug information The full plain-English guide to this medication Lapatinib supplement interactions Every supplement checked against Lapatinib, 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 References The 3 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Lapatinib and Buchu?

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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.