During treatment with crizotinib, close attention should be paid to visual, liver, lung, and heart related symptoms. Early identification and management can help reduce the risk of serious adverse reactions.

1. Visual impairment

1.1 Common manifestations: May present with blurred vision, diplopia, flashes or photophobia, often occurring in the early stages of medication.

1.2 Response measures: If the above symptoms occur, avoid driving or operating precision instruments, and promptly inform the doctor.

1.3 Follow up recommendations: Routine ophthalmic examinations can help evaluate visual changes, and most symptoms can be alleviated with continued treatment.

2. Hepatotoxicity

2.1 Monitoring indicators: During medication, liver function (ALT, AST, bilirubin) should be regularly checked, especially in the first two months.

2.2 Warning signal: If there is yellowing of the skin or eyes, darkening of urine color, or pain in the upper right abdomen, seek medical attention immediately.

2.3 Treatment principle: When the transaminase level significantly increases, the doctor may recommend suspending or reducing the medication, and adjusting the plan after recovery.

3. Interstitial lung disease

3.1 Typical symptoms: newly developed or aggravated dyspnea, dry cough, fever, and non infectious pneumonia should be monitored.

3.2 Emergency medical treatment: Once interstitial lung disease is suspected, medication should be stopped immediately and chest imaging examination should be performed.

3.3 Follow up management: After diagnosis, crizotinib should be permanently discontinued and treatment such as glucocorticoids should be given according to the condition.

4. QT interval prolongation

4.1 Risk factors: Increased risk when combined with electrolyte disorders (such as low potassium and low magnesium), bradycardia, or other QT prolonging drugs.

4.2 Monitoring timing: Regular rechecks of electrocardiogram and electrolytes should be conducted before and during medication, especially in high-risk populations.

4.3 Treatment suggestion: If the QTc interval is significantly prolonged or arrhythmia occurs, medication should be suspended and the cause should be corrected. The decision on whether to resume should be made after evaluation.