Natalizumab is a recombinant humanized IgG4κ monoclonal antibody, with the brand name TYSABRI®. This article will systematically introduce the drug's indications, dosage and administration, and precautions for use, providing a reference for the rational clinical use of the drug.

Indications of Natalizumab

1. Main Indications

It is indicated for the treatment of patients with relapsing multiple sclerosis (MS), and its core value lies in reducing the frequency of clinical deterioration.

2. Precautions for Indications

(1) The safety and efficacy of this drug in patients with chronic progressive multiple sclerosis have not been established.

(2) The safety and efficacy of this drug in children with multiple sclerosis under 18 years of age have not been studied, and it is not recommended for this population.

Dosage and Administration of Natalizumab

1. Standard Dosing Regimen

The recommended dose is 300 mg administered by intravenous infusion every 4 weeks, and the specific usage is as follows:

(1) Preparation Method

Operate using aseptic technique.

Add 15 mL of the concentrated solution (containing 300 mg of the drug) to 100 mL of 0.9% Sodium Chloride Injection, invert gently to mix, and avoid vigorous shaking.

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

(2) Infusion Requirements

The infusion time is approximately 1 hour.

Flush the infusion line with 0.9% Sodium Chloride Injection.

Intravenous push or rapid infusion is prohibited.

2. Patient Monitoring

Closely monitor the patient during the infusion and for 1 hour after the end of the infusion.

If symptoms of hypersensitivity reactions occur, the infusion should be stopped immediately.

Precautions for the Use of Natalizumab

1. Contraindications

It is contraindicated in patients with a confirmed allergy to natalizumab or any of its components.

2. Important Precautions

(1) Hypersensitivity Reactions

The incidence is < 1%, and most occur within 2 hours after the start of infusion.

Symptoms include urticaria, dizziness, fever, rash, chills, etc.

(2) Immunosuppression

Avoid combined use with other immunosuppressants, as this may increase the risk of infection.

(3) Laboratory Monitoring

It may cause an increase in circulating lymphocytes, monocytes, etc., which usually return to baseline levels within 16 weeks after drug withdrawal.

3. Drug Use in Special Populations

(1) Pregnancy

It is classified as Pregnancy Category C. Animal studies have shown that it may affect the fetal hematopoietic system. The pros and cons should be weighed during pregnancy, and consideration should be given to discontinuing the drug.

(2) Lactation

Whether it is excreted in human milk is not clear. It is recommended to decide whether to stop breastfeeding based on the importance of the drug.

(3) Geriatric Use

Clinical research data are insufficient, so it should be used with caution.