Natalizumab is a humanized monoclonal antibody targeting α4-integrin, indicated for the treatment of relapsing forms of multiple sclerosis (MS).
How to Use Natalizumab
Standard Administration Regimen
Dose and Frequency: The recommended dose is 300mg, administered as an intravenous infusion once every 4 weeks, with the infusion duration lasting approximately 1 hour.
Dosage Form and Specification: It is supplied as a 15mL sterile concentrate (300mg/vial), which needs to be diluted with 0.9% Sodium Chloride Injection to a volume of 100mL before use.
Infusion Operation Specifications
Dilution Requirement: Withdraw 15mL of the drug solution and add it to 100mL of 0.9% Sodium Chloride Injection. Gently invert to mix; shaking or freezing is avoided.
Stability: The diluted solution can be stored at room temperature for ≤8 hours, or refrigerated (2-8°C) for ≤24 hours. It must be brought to room temperature before use.
Infusion Monitoring: During the infusion and within 1 hour after the end of the infusion, closely monitor for allergic reactions (such as urticaria, hypotension).
Management of Missed Infusions
If a scheduled infusion day is missed, the infusion should be administered as soon as possible, and the original once-every-4-week schedule should be resumed. No dose adjustment is required.
Dose Adjustment of Natalizumab
Dose Adjustment for Immune-Related Adverse Reactions
Allergic Reactions: In case of systemic allergies (such as dyspnea, hypotension), permanent discontinuation of the drug is required.
Infection Risk: Discontinue administration during the period of severe infection (such as pneumonia); after the infection is controlled, evaluate the necessity of restarting treatment.
Abnormal Liver Enzymes: If Grade 3 liver enzyme elevation persists, discontinue administration temporarily; after liver enzymes return to ≤Grade 1, consider dose reduction or permanent discontinuation.
Natalizumab Administration Regimens for Special Populations
Pregnancy and Lactation
Pregnancy: Animal studies have shown risks of fetal thrombocytopenia and anemia (at 7 times the clinical dose). Data in humans are limited. Contraception is required during drug use, and the drug should be used during pregnancy only when the benefits are significant.
Lactation: Whether the drug is excreted into breast milk is unknown. It is recommended to either discontinue the drug or stop breastfeeding.
Pediatric and Geriatric Patients
Pediatric Patients: Efficacy in patients under 18 years of age has not been established, and its use is not recommended.
Geriatric Patients: Clinical study data are insufficient, and individualized evaluation is required.
Hepatic and Renal Impairment
No dose adjustment is required for patients with mild to moderate hepatic or renal impairment; data on patients with severe impairment are lacking.
Immunocompromised Patients
Concomitant use with immunosuppressants (such as azathioprine) is prohibited, as it may increase the risk of progressive multifocal leukoencephalopathy (PML).
