Tucatinib is an anticancer drug targeting HER2 protein, which is mainly used to treat HER2 positive breast cancer and colorectal cancer. Its side effects can be divided into serious reactions that need vigilance and mild symptoms that may self alleviate.

1 Indications

(1) Combined with trastuzumab and capecitabine to treat adult unresectable or metastatic HER2 positive breast cancer (including brain metastasis), it is applicable to patients who have previously received anti HER2 regimen.

(2) Used in combination with trastuzumab to treat RAS wild-type, HER2 positive metastatic colorectal cancer, suitable for patients who have failed chemotherapy with fluoropyrimidine/oxaliplatin/irinotecan.

2 Side effects and treatment

2.1 Serious side effects requiring immediate medical attention

(1) Nervous system: headache, gait instability, epileptic seizures, or loss of consciousness.

(2) Cardiovascular system: abnormal heart rhythm, abnormal bleeding or edema.

(3) Digestive system: jaundice, clay stools, or persistent vomiting and diarrhea.

(4) Other: Difficulty breathing, blurred vision, or muscle spasms throughout the body.

2.2 Possible Self Relieving Side Effects

(1) Muscle and joint symptoms: back pain, muscle stiffness, or joint pain.

(2) Skin reactions: facial flushing, desquamation of hands and feet, or oral inflammation.

(3) Systemic symptoms: weight loss, fatigue, or constipation.

2.3 Special Preventive Measures

(1) Renal function monitoring: This medication may reversibly increase creatinine levels, and if there are persistent abnormalities, other renal function markers should be used instead.

(2) Drug interactions: Avoid using strong CYP3A inducers/CYP2C8 inhibitors in combination with specific substrate drugs.