Diarrhea, fatigue, and hand foot syndrome during treatment with Lenvatinib are common adverse reactions that require targeted preventive measures and graded management.

1. Diarrhea management

(1) Mild diarrhea (increased bowel movements<4 times per day)

Suggest adjusting diet: avoid high fiber and greasy foods, and increase intake of electrolyte drinks. Oral laxatives such as loperamide can be taken, while monitoring dehydration symptoms such as thirst and decreased urine output.

(2) Moderate to severe diarrhea (≥ 4 times a day or nighttime diarrhea)

Need to pause lenvatinib until symptoms improve and replenish fluids and electrolytes. If grade 2 diarrhea persists for more than 48 hours or grade 3 diarrhea persists, immediate medical attention should be sought, and if necessary, intravenous fluid replacement and medication dosage adjustment should be made.

2. Fatigue relief

(1) Non pharmacological intervention

Reasonably arrange activities and rest periods, and engage in moderate daily exercise such as walking. Optimize sleep environment, avoid caffeine and alcohol intake, and eat high protein foods in small and multiple portions.

(2) Drug intervention

Continuous level 2 fatigue (affecting daily activities) requires assessment of thyroid function and anemia. Medication should be temporarily suspended for level 3 fatigue, and after ruling out other causes, treatment can be resumed with reduced dosage.

3. Coping with Hand Foot Syndrome

(1) Early prevention

Keep the skin of hands and feet moist and use urea ointment. Avoid prolonged friction or high temperature contact, wear loose shoes, socks, and gloves. Starting oral intake of vitamin B6 before treatment may reduce the incidence rate.

(2) Symptom management

Grade 1 (painless redness and swelling) can continue medication and strengthen local care. Grade 2 (painful peeling) requires temporary suspension of lenvatinib until recovery, while grade 3 (ulcerative dermatitis) should be permanently discontinued and treated with specialized care.

4. Key points of comprehensive monitoring

(1) Symptom Diary

Record the time, frequency, and causes of adverse reactions to help doctors assess their severity. Sudden weight loss accompanied by diarrhea should alert oneself to dehydration, while fever accompanied by hand and foot injuries indicates a risk of infection.

(2) Regular follow-up

Assess adverse reactions every 2 weeks during the initial stage of treatment, and conduct monthly follow-up after stabilization. If new or worsening symptoms occur, the medical team should be contacted in a timely manner to avoid adjusting the medication plan on one's own.