When Belzutifan is used to treat VHL related tumors, it is important to focus on managing common adverse reactions such as anemia, hypoxia, and gastrointestinal reactions. By regulating monitoring and timely intervention, drug-related toxicity can be effectively controlled to ensure treatment safety.

1. Anemia management

(1) Incidence: 90% of patients develop anemia, with grade 3 anemia accounting for 7%.

(2) Monitoring: Regularly test hemoglobin before and during treatment, once every 2 weeks in the first month.

(3) Treatment: Suspend administration when hemoglobin<8g/dL, reduce dosage to 80mg after recovery to ≥ 9g/dL, and continue treatment.

2. Risk of hypoxia

(1) Performance: May cause symptoms of hypoxia such as difficulty breathing and fatigue.

(2) High risk groups: patients with chronic lung disease, elderly people, and residents living in high-altitude areas need to strengthen monitoring.

(3) Prevention: Avoid vigorous exercise and promptly assess blood oxygen saturation when symptoms occur.

3. Digestive system reactions

(1) Nausea: incidence rate is 39%. It is recommended to take medication after meals and use antiemetic drugs if necessary.

(2) Constipation: 31% of patients experience it, requiring an increase in dietary fiber and water intake, and may consider laxatives.

4. Symptoms of the nervous system

(1) Headache: 56% of patients experience it, which can be treated symptomatically but should be avoided in combination with strong CYP3A4 inhibitors.

(2) Dizziness: The incidence rate is about 20%. It is recommended to slowly change position and avoid driving or operating machinery.

6. Systemic reactions

(1) Fatigue: 62% of patients reported, it is recommended to take medication in divided doses and arrange activity intensity reasonably.

(2) Fever: Monitor for signs of infection and seek medical evaluation promptly if the body temperature exceeds 38.5 ℃.

6. Special management requirements

(1) Contraceptive requirements: Efficient contraceptive measures should be taken during treatment and one week after discontinuation of medication.

(2) Drug interactions: Avoid using potent CYP3A4 inducers or inhibitors in combination.

(3) Imaging assessment: CT/MRI examination is performed every 12 weeks to evaluate tumor response.