Medical Information

Pralsetinib is a targeted drug used to treat specific RET fusion positive tumors. When using it, attention should be paid to multiple risks such as interstitial lung disease, hypertension, and liver toxicity, and the dosage should be adjusted according to adverse reactions. The following provides a detailed explanation of precautions in clinical monitoring, dosage adjustment, and medication for special populations.

1. Key points of clinical monitoring

(1) Interstitial lung disease/pneumonia: It is necessary to monitor symptoms such as cough and difficulty breathing. When acute respiratory symptoms occur, medication should be suspended and screened. Severe or recurrent cases should be permanently discontinued.

(2) Hypertension: Regularly monitor blood pressure before and during treatment. Medication should be suspended for grade 3 hypertension and permanently discontinued for grade 4 hypertension.

(3) Hepatotoxicity: Frequent monitoring of liver function is required before medication and in the early stages of treatment. For grade 3 or above hepatotoxicity, the dosage should be suspended or adjusted.

2. Principle of dose adjustment

(1) Adverse reaction management: Gradually reduce the dose according to the severity (300mg → 200mg → 100mg), and stop taking when 100mg cannot be tolerated.

(2) Drug interactions: When combined with potent CYP3A inhibitors, the dosage should be reduced, while when combined with inducers, the dosage should be doubled.

3. Medication for special populations

(1) Pregnancy/lactation period: May cause fetal damage, strict contraception is required during medication, and is prohibited during lactation.

(2) Liver and kidney dysfunction: Mild to moderate dose adjustment is not necessary, severe data is insufficient.

(3) Children and the elderly: thyroid cancer patients over 12 years old can use it, and there is no significant difference in safety among the elderly population.

4. Standard dose

Adult non-small cell lung cancer, thyroid cancer, and children aged 12 and above with thyroid cancer: 400 milligrams orally once daily, continue treatment until disease progression or intolerable toxicity.

5. Dose adjustment

(1) Adverse reaction adjustment

Reduce the initial dose to 300 milligrams per day, the second dose to 200 milligrams per day, and the third dose to 100 milligrams per day. Those who cannot tolerate 100 milligrams should discontinue the medication. Specific adjustments need to be classified according to the type of adverse reactions (such as interstitial lung disease, hypertension, hepatotoxicity, etc.).

(2) Drug interaction adjustment

When used in combination with P-gp or potent CYP3A inhibitors, the dosage should be reduced to 200 milligrams or 100 milligrams per day; After 7 days of combined use with a potent CYP3A inducer, the dosage needs to be doubled. Restore the original dosage after discontinuing the relevant medication.

6. Special population dosage

Patients with mild to moderate renal or liver dysfunction do not need to adjust the dosage, while severe or end-stage patients do not have clear data and should be used with caution.