Tukysa® (tucatinib) Tablets for HER2-Positive Cancers

What Tukysa Is and How It Works

Tukysa® (tucatinib) is an oral HER2-directed tyrosine kinase inhibitor. It is used with trastuzumab and capecitabine for adults with HER2‑positive unresectable or metastatic breast cancer, including patients with brain metastases. It is also used with trastuzumab for RAS wild‑type, HER2‑positive metastatic colorectal cancer after standard therapy. You can buy Tukysa online from YouDrugstore to access Canadian pricing and careful pharmacist oversight.

YouDrugstore is a licensed Canadian pharmacy in Manitoba. Our pharmacists review prescriptions before dispensing. You can order online or by phone and reach our friendly customer-service chat during posted office hours. We ship to the US.

We source through licensed, vetted partner pharmacies so you receive authentic brand medicines at fair prices and a broad selection.

Tucatinib blocks HER2 signaling inside cancer cells. This helps slow or stop tumor growth. Its design supports activity in the central nervous system, which is important for patients with brain metastases. Tablets come in 50 mg and 150 mg strengths.

Dosage and Usage

Your oncology team sets your exact regimen. Typical schedules are below for general reference.

• Usual adult dose: 300 mg by mouth twice daily.
• Breast cancer: take Tukysa® with trastuzumab and capecitabine continuously.
• Colorectal cancer: take Tukysa® with trastuzumab continuously.
• Swallow tablets whole with water. Do not crush, split, or chew.
• Take with or without food at consistent times, about 12 hours apart.
• If you miss a dose, take the next dose at the usual time. Do not double dose. If you vomit, take the next scheduled dose.
• Your prescriber may pause or reduce the dose for side effects.
• Avoid strong CYP2C8 or CYP3A modulators when possible. Your care team will guide adjustments.

• Store Tukysa® at 20–25°C (68–77°F); brief 15–30°C excursions are allowed.
• Keep in the original bottle with the cap tightly closed. Protect from moisture.
• Keep out of reach of children and pets.
• For travel, carry in hand luggage with your prescription label. Avoid heat and direct sun.
• Bring extra doses in case of delays.

Benefits and Savings

Tukysa® improved progression‑free survival and response rates in clinical studies. Benefits extended to patients with active or stable brain metastases. The oral route adds convenience. You take it at home as part of combination therapy. Many patients appreciate the predictable twice‑daily schedule.

YouDrugstore offers brand and generic medicines at Canadian prices and also carries OTC health products. US customers often see 60–80% savings compared with typical US retail prices. You can set simple reorder reminders, and multi‑month supplies may reduce your per‑month cost where permitted.

Side Effects and Safety

Not all patients experience side effects, and many are manageable. Your oncology team monitors labs and symptoms.

• Common: diarrhea, nausea, vomiting, mouth sores, decreased appetite, abdominal pain.
• Skin: palmar‑plantar erythrodysesthesia (hand‑foot syndrome), especially with capecitabine.
• General: fatigue, headache, cough.
• Lab changes: increased liver enzymes (ALT, AST) and bilirubin, anemia.
• Serious: severe diarrhea or dehydration, severe liver injury, severe hand‑foot reactions.
• Heart: trastuzumab may reduce left ventricular function; report new shortness of breath or edema.
• Allergic reactions are rare but can occur.
• Pregnancy: may harm a fetus. Use effective contraception during treatment and for a short period after the last dose as directed by your prescriber.
• Breastfeeding: do not breastfeed during treatment and for a short period after the last dose.

Drug interactions matter. Tucatinib is a substrate of CYP2C8 and CYP3A. Strong inhibitors can raise levels, and strong inducers can lower levels. Tucatinib can raise exposure to other drugs that are CYP3A, P‑gp, BCRP, or OATP1B1/1B3 substrates. Examples include midazolam, digoxin, and rosuvastatin. Your team may adjust doses or switch therapies.

Onset Time

Response is assessed over weeks to months. Many patients have scans about every 6–12 weeks. Some see early stabilization of disease. Others may need more time before benefit is clear. Your oncology team will set follow‑up intervals and review imaging and labs with you.

Compare With Alternatives

Several HER2‑targeted options exist. Neratinib (Nerlynx®) is another oral HER2 TKI, often used after trastuzumab‑based therapy. It has a higher rate of diarrhea, and antidiarrheals are commonly used from the start. Lapatinib (Tykerb®) is an older HER2/EGFR TKI with a different profile and combination partners.

Antibody‑drug conjugates, such as trastuzumab deruxtecan, may be used at other points in therapy. Choice depends on prior treatments, sites of disease, side‑effect risks, and goals of care. Your oncologist will guide sequencing.

Hormonal therapies target a different biology. For hormone receptor‑positive disease, options may include Anastrozole, Exemestane, or Fulvestrant alongside HER2‑targeted treatment in selected cases. These are not direct substitutes for Tukysa® but may be used in combination plans.

Combination Therapy

Tukysa® is part of combination regimens. For metastatic breast cancer, it is taken with trastuzumab and capecitabine. Your team will set capecitabine cycles and trastuzumab dosing. For metastatic colorectal cancer, Tukysa® pairs with trastuzumab alone.

Supportive care is important. Your team may recommend antidiarrheals, skin care for hand‑foot reactions, and routine lab checks. They will also manage potential heart effects from trastuzumab. Do not start, stop, or change other medicines without discussing interactions.

Patient Suitability and Cost-Saving Tips

Adults with HER2‑positive unresectable or metastatic breast cancer who have received prior anti‑HER2 therapy may be candidates. Patients with brain metastases were included in trials and may benefit. For metastatic colorectal cancer, candidates have RAS wild‑type, HER2‑positive tumors after standard lines.

It is not used for HER2‑negative cancers. Tell your team about liver disease. Dose changes may be required for significant hepatic impairment. Report persistent diarrhea, jaundice, or dark urine promptly. Review all medicines, supplements, and herbal products for interactions.

You can lower costs by ordering a longer supply when appropriate and allowed. Reorder before you run low to avoid gaps. Our team can send reminders. We also list periodic offers and bulk options on our site. Explore education and support in our Breast Cancer and Cancer pages.

If you want general cancer awareness content, see World Lung Cancer Day 2025 Awareness That Saves Lives and brain‑health advocacy in World Brain Day 2025 Empowering Healthy Minds At Every Age.

Authoritative Sources

Review official information before starting therapy. See the Tukysa patient and caregiver site, the FDA approval and prescribing information, and the Health Canada Drug Product Database.

Ready to get started? Create your account, send your prescription, and our team will take care of the rest. We offer prompt, express, cold-chain shipping options as needed, careful handling, and support from ordering to delivery.

This content is for general information. It does not replace medical advice. Always follow your prescriber’s instructions for dosing, lab monitoring, and side‑effect management. A valid prescription is required for dispensing.