Drug & supplement interaction

Bittersweet Nightshade + 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 Bittersweet Nightshade 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. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

Bittersweet Nightshade 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 Bittersweet Nightshade 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.

Worth understanding: our licensed dataset holds no drug-interaction record for Bittersweet Nightshade at all — not against Lapatinib, and not against any other medication we track. This verdict therefore rests on the absence of any recorded data, not on research that looked at this combination and found nothing. We cannot rule an interaction out.

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.

Bittersweet Nightshade safety at a glance

Bittersweet Nights... overall Avoid The plant contains toxic alkaloids and is generally considered unsafe to take by mouth without medical supervision.
Pregnancy Likely Unsafe When used orally. The alkaloids of the plant, solasodine, soladulcine, and related compounds have been linked to birth defects in animals; avoid using. There is... Read the full pregnancy detail
Breastfeeding Likely Unsafe When orally; avoid using. There is insufficient reliable information available about the safety of bittersweet nightshade when used topically; 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 Bittersweet Nightshade? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
What to actually watch for

No Interaction Found — But Data Suggests Bittersweet Nightshade and Lapatinib May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Diarrhea / Vomiting reported in 27.1% of FDA reports for Lapatinib Additional detail

    Bittersweet Nightshade

    “When used orally, the leaves and berries of bittersweet nightshade may be unsafe. There is limited information available about the adverse effects of the stem of bittersweet nightshade when used in medicinal amounts.

    Serious Adverse Effects (Rare):

    Orally: The leaves and berries can cause toxicity, including circulatory and respiratory depression, convulsions, cyanosis, diarrhea, dilated pupils, gastrointestinal blee…”

    Bittersweet Nightshade · Natural Medicines adverse-effect record, reported in cluster headache.

    “Orally, bittersweet nightshade leaf and berry can cause diarrhea, gastrointestinal bleeding, scratchy throat, vomiting and (6).”

    Bittersweet Nightshade · Natural Medicines adverse-effect record, reported in diarrhea.

    1 source cited
    1. 6. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.

    Lapatinib

    Listed in the ADVERSE REACTIONS section of the FDA label for Lapatinib, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for Bittersweet Nightshade but not commonly for Lapatinib: bleeding in the gut, sore throat, seizures and low mood.

Effects for Lapatinib come from the ADVERSE REACTIONS section of its FDA label; effects for Bittersweet Nightshade come from the Natural Medicines adverse-effect record, quoted above. 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. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Special populations

Bittersweet Nightshade in Pregnancy & Breastfeeding

Pregnancy Likely Unsafe

When used orally. The alkaloids of the plant, solasodine, soladulcine, and related compounds have been linked to birth defects in animals; avoid using. There is insufficient reliable information available about the safety of bittersweet nightshade when used topically during pregnancy; avoid using.

Lactation Likely Unsafe

When orally; avoid using. There is insufficient reliable information available about the safety of bittersweet nightshade when used topically; 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 Bittersweet Nightshade 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 Bittersweet Nightshade as Part of a Dietary Supplement Product? Check It for Interactions

We hold 14 real supplement products containing Bittersweet Nightshade, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Bittersweet Nightshade. Even though Bittersweet Nightshade 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 Bittersweet Nightshade 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 Bittersweet Nightshade
Steady interest

#1,193 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Lapatinib
Steady interest

#2,248 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 Bittersweet Nightshade reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The Bittersweet Nightshade 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 Bittersweet Nightshade

What is Bittersweet Nightshade?

Bittersweet Nightshade
  • Skin conditions like eczema and warts
  • Inflammation and joint discomfort
  • Muscle spasms
  • Respiratory complaints
  • Mild fluid retention (traditional 'cleansing' use)

Bittersweet nightshade is a traditional herb with toxic compounds, especially in its berries, and there is very little reliable human evidence that it works for any health condition. Because it can cause serious poisoning, it is not recommended for self-treatment, and it should be avoided during pregnancy and breastfeeding.

Solanum dulcamara · Solanaceae · Stems (twigs), leaves, and sometimes berries · Dried stems, teas, tinctures, topical ointments or creams, homeopathic preparations

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

Bittersweet Nightshade: dosing

There is no established safe or standardized dose for bittersweet nightshade. Because the plant is toxic and the amount of active alkaloids can vary widely, it is not possible to give a reliable, safe amount to take by mouth.If you encounter a commercial product (such as a topical cream or a homeopathic remedy), follow the label exactly and do not exceed the recommended use. We do not recommend taking bittersweet nightshade internally for self-treatment.

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

Read the full Bittersweet Nightshade 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 & Bittersweet Nightshade

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

0Major
0Moderate
0Minor
2,829No known interaction
2,829 No interaction
No interaction 2,829 drugs checked — show the list

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

Showing the 60 most looked-up of 2,829 medications checked with no known interaction — see the full Bittersweet Nightshade list.

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

Bittersweet Nightshade References

The 1 references that drive our Bittersweet Nightshade 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. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.

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 Bittersweet Nightshade and Lapatinib Together: Common Questions

Is it safe to take Bittersweet Nightshade with Lapatinib?
We do not list a known interaction between Bittersweet Nightshade 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.
Do Bittersweet Nightshade and Lapatinib have any of the same side effects?
Yes — our sources link each of them separately to 2 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
Does Lapatinib interact with any supplements?
Yes. Lapatinib has documented interactions with 143 supplements in our database — Bittersweet Nightshade 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

Bittersweet Nightshade 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 1 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Lapatinib and Bittersweet Nightshade?

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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.