Alemtuzumab Injection (Lemtrada) is a CD52-directed cytolytic monoclonal antibody used for the treatment of relapsing forms of multiple sclerosis (MS). Due to its unique pharmacological effects and potential risks, strict adherence to medication guidelines and systematic monitoring are required during its use.

Precautions for the Use of Alemtuzumab Injection (Lemtrada)

1. Prevention of Severe Autoimmune Risks

(1) Alemtuzumab may induce a variety of severe autoimmune diseases, including immune thrombocytopenia (ITP), anti-glomerular basement membrane disease, and others.

(2) After receiving the medication, patients should be closely monitored for signs of bleeding tendency (such as abnormal bruising, epistaxis, hematuria) and manifestations of renal dysfunction (such as edema, decreased urine output).

(3) If any relevant symptoms occur, patients must seek medical attention immediately. Early intervention can significantly improve the prognosis.

2. Management of Infusion Reactions

(1) Severe reactions may occur during the infusion and within 24 hours after the infusion, including allergic reactions, myocardial ischemia, and even stroke.

(2) All infusions must be performed in a medical institution equipped with emergency equipment and under the supervision of professional personnel.

(3) Patients should be observed for at least 2 hours after the infusion. Medical staff should inform patients of the possible manifestations of delayed reactions and the corresponding emergency treatment measures.

3. Usage Restrictions in Special Populations

(1) Alemtuzumab is contraindicated in the following populations: patients allergic to the active ingredient or excipients, patients with human immunodeficiency virus (HIV) infection, and patients with active infections.

(2) Women of childbearing age must take effective contraceptive measures during the medication period and within 4 months after the last dose, as the drug may cause harm to the fetus.

(3) Lactating women should weigh the necessity of continued treatment to decide whether to discontinue the medication or stop breastfeeding.

4. Essential Pretreatment Measures

(1) Three days before the start of each treatment course, high-dose corticosteroids (such as 1000 mg methylprednisolone or an equivalent drug) should be administered in advance to reduce the risk of infusion reactions.

(2) Prophylactic treatment against herpes viruses should be initiated simultaneously from the first day of drug administration and continued for at least 2 months or until the CD4+ lymphocyte count recovers to more than 200 cells/μL, whichever is later.

5. Standards for Drug Preparation and Infusion

(1) Before use, visually inspect the drug solution to ensure it is clear and free of particles. Strict aseptic technique must be followed during dilution: inject 1.2 mL of the drug solution into 100 mL of normal saline or 5% glucose solution and mix gently.

(2) The diluted drug solution should be stored away from light and used within 8 hours.

(3) Sharing the infusion line with other drugs is strictly prohibited. Intravenous push or rapid infusion is also forbidden.

Medication Monitoring for Alemtuzumab Injection (Lemtrada)

1. Laboratory Monitoring

(1) Baseline examinations must be completed before medication administration, including complete blood count (CBC) with differential, serum creatinine, routine urinalysis and urine cell count, thyroid function, liver function, and coagulation function.

(2) Post-medication monitoring is divided into three phases: monthly monitoring of blood and urine routines until 48 months after the last dose; thyroid function testing every 3 months; and annual skin examinations to screen for melanoma.

2. Key Monitoring Items

(1) Hematological System Monitoring: Focus on thrombocytopenia (ITP). Monthly CBC monitoring enables early detection. Emergency intervention is required if the platelet count is ≤ 20,000/μL.(2) Renal Monitoring: Abnormal urine protein/creatinine ratio or hematuria indicates a possible occurrence of anti-GBM disease, which requires immediate evaluation.

(3) Thyroid Monitoring: 36.8% of patients develop thyroid diseases, including Graves' disease and thyroiditis, which require long-term follow-up.