The contraindications for Pacritinib mainly include patients with severe heart block and active bleeding, and strict adherence to contraindication standards is necessary to ensure medication safety. The following provides a detailed explanation of precautions from three aspects: specific contraindications, risk assessment, and alternative solutions.

1. Severe heart block patient

(1) Absolute contraindication: Patients with baseline QTc interval>500ms or with grade II or higher atrioventricular block are prohibited from using the medication as it may increase the risk of arrhythmia.

(2) Risk assessment: Prior to medication, a complete electrocardiogram examination is required. For patients with electrolyte imbalances, hypokalemia/hypomagnesemia should be corrected before evaluation.

2 active bleeding patients

(1) Taboo scope: including gastrointestinal bleeding, intracranial bleeding, and recent major surgery (<4 weeks) patients, as drugs may inhibit platelet function.

(2) Risk management: Avoid using anticoagulant/antiplatelet drugs during treatment, and suspend medication for mild bleeding symptoms such as hemorrhoid bleeding.

3 Other high-risk taboo groups

(1) Severe liver damage: Not recommended for Child Pugh C patients as drug metabolism disorders may lead to toxic accumulation.

(2) Pregnancy period: Animal studies have shown embryotoxicity, and pregnant women and women planning to conceive should avoid it throughout the entire process.

4 alternative treatment options

(1) High risk heart patients: JAK inhibitors such as rosotinib with lower risk of QT prolongation may be considered, but platelet count needs to be evaluated.

(2) Patients with bleeding tendency: It is recommended to use non pharmacological therapies such as thrombopoietin receptor agonists or transfusion support for transition.