Neratinib
Neratinib is a targeted kinase inhibitor used to treat HER2-positive breast cancer — either as extended follow-up therapy after early-stage treatment or for advanced and metastatic disease.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
📖 Neratinib: Patient Information Guide
A plain-language walkthrough of Neratinib — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Neratinib is a HER2-targeted cancer treatment approved for two specific settings in adults with HER2-positive breast cancer:
- Nerlynx (as a single agent) — extended adjuvant treatment for early-stage HER2-positive breast cancer, taken after completing adjuvant (post-surgery) trastuzumab-based therapy, to further reduce the risk of cancer returning
- Nerlynx (combined with capecitabine) — treatment of advanced or metastatic HER2-positive breast cancer in patients who have already received two or more HER2-targeted regimens for metastatic disease
⚙️How it works▾
Neratinib is a kinase inhibitor — a drug that blocks specific proteins (called kinases) that cancer cells use to grow. It permanently and irreversibly locks onto three related proteins: HER2, EGFR (epidermal growth factor receptor), and HER4. By blocking these signals, neratinib cuts off instructions that tell cancer cells to multiply, slowing or stopping tumor growth. Several active breakdown products of neratinib in the body also continue to block these same targets.
💊How it's taken▾
Nerlynx comes as a tablet taken once daily by mouth, always with food, at about the same time each day. Tablets must be swallowed whole — do not chew, crush, or split them.
- For early-stage breast cancer, Nerlynx is taken continuously for up to one year (or until disease recurrence)
- For advanced or metastatic breast cancer, Nerlynx is taken on days 1–21 of a 21-day cycle alongside capecitabine
- Your doctor may start you at a lower dose for the first two weeks and increase gradually — a strategy to reduce diarrhea severity
- If you miss a dose, skip it and take your next dose as scheduled; never double up
🤒Side effects — in detail▾
The most common side effects with Nerlynx include:
- Diarrhea (very common; can be severe — preventive treatment is given from day one)
- Nausea and vomiting
- Stomach pain and cramping
- Fatigue or weakness
- Decreased appetite and weight loss
- Rash or skin changes, dry skin
- Mouth sores (stomatitis)
- Muscle spasms, nail changes
Seek prompt medical attention for severe or persistent diarrhea, signs of dehydration (dizziness, little urination, dry mouth), yellowing of the skin or eyes, dark urine, or worsening fatigue — these may signal serious liver or kidney problems.
⚠️Warnings & precautions▾
- Diarrhea: Occurs in most patients and can lead to dangerous dehydration, low blood pressure, and kidney failure if untreated. Your doctor will prescribe preventive loperamide starting with your first dose, or use a gradual dose escalation strategy. Severe or persistent diarrhea may require pausing or reducing your dose. Call your care team early — do not wait.
- Liver toxicity (hepatotoxicity): Nerlynx can raise liver enzyme levels. Your doctor will check your liver labs monthly for the first three months, then every three months. Report yellowing of skin or eyes, dark urine, right-sided stomach pain, fever, rash, or unusual tiredness immediately.
- Embryo-fetal toxicity: Neratinib can cause serious harm to an unborn baby based on animal data. Effective contraception is required during treatment and for at least one month after the last dose for females; males should use contraception for three months after the last dose.
🔀What it interacts with▾
Several types of medications and substances can significantly affect how Nerlynx works or increase its side effects:
- Proton pump inhibitors (PPIs, e.g., omeprazole, pantoprazole): Avoid — they significantly reduce neratinib absorption and may make it much less effective
- H2 blockers (e.g., famotidine, ranitidine): Time Nerlynx at least 2 hours before or 10 hours after your H2 blocker dose to reduce the impact on absorption
- Antacids: Take Nerlynx at least 3 hours after antacids
- Strong CYP3A4 inhibitors (e.g., ketoconazole, certain HIV medications): Avoid — can dramatically increase neratinib levels and raise side effect risk
- Strong or moderate CYP3A4 inducers (e.g., rifampin, efavirenz): Avoid — can dramatically lower neratinib levels and reduce effectiveness
- P-gp and moderate CYP3A4 dual inhibitors (e.g., verapamil): Avoid — can substantially raise neratinib levels
- Digoxin and other P-gp substrate drugs: Nerlynx may raise the levels of these medications — your doctor will monitor you closely for their side effects
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Pregnancy: Neratinib can cause serious fetal harm — a pregnancy test is recommended before starting. Do not use if pregnant unless the risk has been carefully discussed with your doctor.
- Contraception (females): Use effective birth control during treatment and for at least 1 month after your last dose
- Contraception (males): Use effective birth control during treatment and for 3 months after your last dose if your partner could become pregnant
- Breastfeeding: Do not breastfeed while taking Nerlynx or for at least 1 month after your last dose — potential serious harm to the infant
- Severe liver impairment: A lower starting dose is required; tell your doctor about any history of liver disease
- Children: Safety and effectiveness in pediatric patients have not been established — not approved for use in children
- All other medications: Tell your prescriber and pharmacist about every medication, supplement, herbal product, and antacid you take before starting Nerlynx
🚑If you take too much▾
There is no specific antidote for a Nerlynx overdose. If too much is taken, the most likely effects are worsening gastrointestinal symptoms — diarrhea, nausea, vomiting, and dehydration — as these side effects appear to be dose-related. If an overdose is suspected, stop taking the medication and seek immediate medical attention; supportive care (fluids, monitoring) will be provided.
📡Pharmacodynamics — effects in the body▾
Neratinib works by irreversibly blocking the activity of HER2, EGFR, and HER4 receptor proteins inside cancer cells, reducing the signaling that drives cell growth. At doses well above the usual therapeutic level tested in healthy volunteers, Nerlynx did not cause any clinically meaningful changes in heart rhythm (specifically the QTc interval), which is reassuring from a cardiac safety standpoint. The precise relationship between neratinib blood levels and its anti-cancer effect over time has not been fully characterized.
🔬Pharmacokinetics — how your body processes it▾
After swallowing a Nerlynx tablet, peak levels in the blood are reached within about 2 to 8 hours. Taking it with a high-fat meal substantially increases how much neratinib the body absorbs — which is why it should always be taken with food. Neratinib is broken down mainly in the liver (by an enzyme called CYP3A4) and leaves the body almost entirely through the stool (about 97%), with very little exiting through the urine. Its half-life — the time for half the drug to clear the body — is roughly 7 to 17 hours in patients. People with severe liver disease absorb significantly more neratinib, which is why a lower starting dose is used in that group.
📦How to store it▾
Store at controlled room temperature, 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) .
📄 Written from Neratinib’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
Supplements & herbs that interact with Neratinib
168 supplements and herbal products have documented interactions with Neratinib in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 6
- Moderate · 124
- Minor · 38
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Neratinib — the kind of thing our pharmacy team would talk through with you at the counter.
Why is diarrhea such a big deal with this medication, and what can I do about it? ▾
Do I need to take Nerlynx with food, or does it matter? ▾
Can I take my heartburn or antacid medication while on Nerlynx? ▾
Is it safe to get pregnant or try to have a baby while taking this medication? ▾
What signs should make me call my doctor right away? ▾
What if I miss a dose? ▾
Is Neratinib available over the counter? ▾
When was Neratinib first available? ▾
Who makes Neratinib? ▾
💬 Answers drafted from Neratinib’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Neratinib comes
Neratinib is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Tablet
How this form is used
- Nerlynx is used alone as extended adjuvant treatment for early-stage HER2-positive breast cancer following trastuzumab-based therapy
- Nerlynx is used in combination with capecitabine for advanced or metastatic HER2-positive breast cancer after two or more prior HER2-targeted regimens
- Nerlynx tablets are taken once daily by mouth, with food, at approximately the same time each day
- Nerlynx tablets must be swallowed whole — do not chew, crush, or split them
- If you miss a dose of Nerlynx, skip it entirely and resume with your next scheduled dose — do not take two doses to make up for a missed one
- Nerlynx may be started at a lower dose for the first two weeks and gradually increased — or started with a preventive anti-diarrhea medicine — to help manage diarrhea; follow your prescriber's instructions
📊 Neratinib across the U.S. market
How Neratinib appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
Also listed with the FDA, not a patient dose form: Powder (3) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Neratinib is used
A general measure of how commonly Neratinib is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Neratinib is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Neratinib prescribed? Of the 1,596 medications we measure, Neratinib ranks #1,319 by Medicaid prescriptions — more than 17% of them.
Utilization by Neratinib product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
neratinib 40 MG Oral Tablet
Summed across the 2 of 5 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1940648
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Neratinib, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 2 of 5 listed Neratinib NDCs with Medicaid activity.
🔍 Compare Neratinib products
A representative set of FDA-listed product records for Neratinib — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 40 mg | — | Excella GmbH & Co. KG | DRUG FOR FURTHER PROCESSING | View NDC → |
| 40 mg | Oral | Puma Biotechnology, Inc. × 4 listings | NDA | View NDC → |
| 💊Bulk drug substance | ||||
| 1 kg/kg | — | MSN Laboratories Private Limited × 2 listings | BULK INGREDIENT | View NDC → |
| 5 kg/5 kg | — | TAPI Croatia Industries Ltd. | BULK INGREDIENT | View NDC → |
Showing 8 of 8 products — FDA National Drug Code Directory. See every product, package size and price: browse all 8 Neratinib NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Neratinib — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Neratinib in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Neratinib went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 1940643 1 dose form · 1 strength
-
Dose form (SCDF) Oral Tablet RxCUI 1940647In current FDA listingsClinical drug / strength (SCD) 40 MGRxCUI 1940648
Look up RxCUI 1940643 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Neratinib is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Neratinib belongs to the Kinase Inhibitor class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 1 FDA-filed SPL label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Puma Biotechnology, Inc. is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.