Natalizumab is a recombinant humanized IgG4κ monoclonal antibody, primarily indicated for the treatment of relapsing multiple sclerosis.

How to Use Natalizumab

Administration Regimen

The standard recommended dose of Natalizumab is 300mg administered via intravenous infusion once every 4 weeks.

The drug must be diluted and prepared before use.

Preparation Method

The preparation process must strictly adhere to the principles of aseptic technique.

Withdraw 15mL of the concentrated solution from a single-use vial.

Inject it into 100mL of 0.9% sodium chloride injection.

Gently invert to mix; do not shake.

The prepared solution should be used immediately or stored refrigerated at 2-8°C, and must be used within 8 hours.

Infusion Specifications

Infusion time: The diluted solution should be administered via intravenous infusion over approximately 1 hour.

After infusion: The infusion line must be flushed with 0.9% sodium chloride injection.

Observation requirements: Closely monitor the patient's response during the infusion and for 1 hour after the infusion is completed.

Prohibited procedures: Intravenous push or rapid infusion is forbidden, and mixing with other drugs for co-infusion is also not allowed.

Dosage Adjustment of Natalizumab

Routine Dosage Adjustment

Clinical trial data indicate that routine dosage adjustment of Natalizumab is not required.

When used in combination with interferon beta-1a (AVONEX®), although the clearance rate decreases by approximately 30%, safety data show that no dosage adjustment is needed.

Dosage Adjustment Under Special Circumstances

Patients with positive antibodies: Approximately 6% of patients develop persistent antibodies, leading to a significant reduction in drug concentration (<1mcg/mL). The clinical effect is similar to that of a placebo, and discontinuation of the drug should be considered.

Overdosage: The safety of doses exceeding 300mg has not been fully evaluated, and the maximum safe dose has not been determined.

Drug interactions: Concurrent use with immunosuppressants may increase the risk of infection, so co-administration should be avoided.

Natalizumab Use in Special Populations

Elderly Patients

Clinical studies did not include a sufficient number of patients aged 65 years or older to determine whether the response of elderly patients differs from that of younger patients.

Pregnant Women

Pregnancy category C: Animal studies show that at 7 times the clinical dose, the drug can cross the placenta, causing mild fetal anemia, thrombocytopenia, etc.

Data on human pregnancy are limited, and the drug should be used only when clearly necessary.

If the drug is found to be used during pregnancy, consideration should be given to discontinuing it.

Lactating Women

It is not yet clear whether the drug is excreted in human milk. Given the risk of potential serious adverse reactions, the necessity of treatment should be weighed to decide whether to discontinue breastfeeding or the drug.

Pediatric Patients

The efficacy of Natalizumab in patients with multiple sclerosis under 18 years of age has not been studied, and its use in pediatric patients is not recommended.