Pyrotinib is a small-molecule tyrosine kinase inhibitor (TKI) targeting HER2-positive breast cancer. It inhibits tumor growth by blocking the HER2 signaling pathway and is primarily used for second-line and subsequent treatment of advanced or metastatic HER2-positive breast cancer. It must be used strictly as prescribed by a physician, and patients should not adjust the dosage or discontinue the medication on their own.
Mechanism of Action and Indications
Mechanism of Action: Pyrotinib irreversibly binds to HER2 receptors, blocking downstream signal transduction and thereby inhibiting tumor cell proliferation and survival.
Indications: It is approved for patients with HER2-positive advanced breast cancer, particularly those whose disease has progressed following prior therapy with agents such as trastuzumab. It is commonly used in combination with chemotherapy agents (such as capecitabine).
Precautions During Medication Use
Prescription Regulation: Treatment regimens must be formulated by a physician based on the patient's pathological subtype, genetic testing results, and clinical status. Self-medication is strictly prohibited.
Treatment Cycle: It is typically administered in cycles of "21 days of treatment followed by 7 days off", with specific adjustments made based on patient tolerability.
Contraindications: Contraindicated in patients allergic to any component of the drug, pregnant or breastfeeding women, and patients with severe hepatic or renal impairment.
Common Side Effects and Management
Diarrhea: Occurs with high frequency. Mild diarrhea can be managed through dietary adjustments or antidiarrheal medications; severe cases require temporary treatment interruption and medical evaluation.
Skin Reactions: Such as rash and hand-foot syndrome, which can be managed with topical treatments while avoiding ultraviolet light exposure.
Other Reactions: Include fatigue, decreased appetite, and abnormal liver function, requiring regular monitoring of relevant clinical parameters.
Monitoring and Follow-up During Treatment
Regular Evaluations: Tumor markers, imaging changes, and HER2 status should be assessed every 2–3 months.
Adverse Effect Monitoring: Particular focus should be placed on hepatic and renal function, electrolyte levels, and cardiac function (such as left ventricular ejection fraction).
Follow-up Adjustments: In the event of disease progression or unacceptable toxicity, the treating physician may alter the treatment plan.
Note: Pyrotinib is a prescription medication. HER2 testing (immunohistochemistry or FISH) must be completed prior to use. Strictly follow medical guidance throughout treatment and seek timely medical care if discomfort occurs.
