Lenvatinib has clear contraindications in patients with severe liver and kidney dysfunction and pregnant women, and strict adherence to medication safety regulations is required. The following provides a detailed explanation from the perspectives of taboo population classification and special precautions, covering key limitations and risk warnings for clinical medication.

1. Patients with severe liver and kidney dysfunction

(1) Liver dysfunction

Lenvatinib is contraindicated in patients with Child Pugh C cirrhosis. Patients with moderate to severe liver damage should reduce their dosage by 50% and closely monitor liver function indicators. If there is grade 3-4 liver toxicity, the medication should be stopped immediately.

(2) Renal insufficiency

End stage renal disease (creatinine clearance rate<15mL/min) or dialysis patients are contraindicated. Patients with moderate to severe kidney damage should use it with caution. It is recommended to reduce the starting dose to 14mg/day and monitor changes in urinary protein and renal function.

2. Pregnant and lactating women

(1) Pregnancy taboos

Based on animal teratogenic data, use by pregnant women can lead to fetal malformations. Pregnancy status must be confirmed before treatment, and women of childbearing age should take effective contraceptive measures during medication and within 30 days after discontinuation.

(2) Breastfeeding restrictions

Medications may be secreted through breast milk, and medication or feeding should be stopped during lactation. It is recommended to avoid breastfeeding for at least one week after the last administration to reduce the risk of infant exposure.

3. Other absolutely taboo groups

(1) History of drug allergies

Individuals with a history of hypersensitivity reactions to lenvatinib or excipients are prohibited from using it, including severe rash, angioedema, and other allergic symptoms.

(2) Active bleeding

Patients with recent hemoptysis, gastrointestinal bleeding, or brain metastases with a tendency to bleed should avoid using medication as it may increase the risk of bleeding.