Pyrotinib dimaleate is primarily used in the treatment of HER2-positive breast cancer. It functions as a dual tyrosine kinase inhibitor, specifically targeting and blocking both the HER2 and EGFR receptors, which are often overexpressed in certain types of breast cancer. By inhibiting these receptors, it helps to slow down or stop the growth of cancer cells. This medication is particularly beneficial for patients who have not responded well to other HER2-targeted therapies. It is commonly administered orally, making it a convenient option for ongoing treatment. Clinical studies have shown that pyrotinib dimaleate can significantly improve progression-free survival in patients with advanced or metastatic HER2-positive breast cancer, especially when used in combination with other chemotherapeutic agents. Common side effects include diarrhea, nausea, and fatigue. It should be used under close medical supervision. Its role in managing this aggressive form of cancer highlights its importance in modern oncology.