The daily dosage of Selinexor should be calculated based on the dosage form specifications and prescription dosage, and the specific dosage should strictly follow the doctor's advice. The following provides a detailed explanation from the aspects of standard dosage, dosage adjustment, and precautions.

1 Standard Dose Protocol

(1) Multiple myeloma: The recommended dose is 80mg orally, twice a week (such as Monday and Thursday), and should be used in combination with dexamethasone.

(2) Diffuse large B-cell lymphoma: The recommended dose is 60mg orally, once a week, and treatment should be continued until disease progression or intolerance occurs.

2 dose conversion and particle count calculation

(1) 20mg tablets: 4 tablets are required for an 80mg dose, and 3 tablets are required for a 60mg dose.

(2) The entire tablet should be swallowed and should not be broken or crushed. It is recommended to take the medication in the morning.

3 Principles of Dose Adjustment

(1) Hematological toxicity: When the platelet count is less than 50 × 10 ⁹/L or the neutrophil count is less than 0.5 × 10 ⁹/L, the medication should be suspended and reduced by 20% after recovery.

(2) Non hematological toxicity: Adverse reactions of grade 3 or above require discontinuation of treatment. After recovery, continue at 75% of the original dose.

4 Special precautions

(1) It should be taken with meals and ensure sufficient hydration to reduce gastrointestinal reactions.

(2) After missing the dose, it can be taken within 12 hours, and if it exceeds 12 hours, the dose will be skipped.