As an immunomodulatory drug, the adverse reactions of Ocrelizumab involve multiple systemic reactions and require different treatment measures based on the severity of symptoms.

1. Common adverse reactions

Infusion related reactions: After the first infusion, facial flushing, headache, or hypotension may occur, with an incidence rate of about 35%, which can usually be relieved by slowing down the infusion rate. Upper respiratory tract infection: manifested as nasal congestion and sore throat, with an incidence rate of about 40%, mostly mild self limiting. Skin reactions: including itching or rash, with an incidence rate of about 15%, can be relieved by local use of antihistamines.

2. Serious reactions requiring immediate medical attention

(1) Infection related symptoms

Continuous fever exceeding 38.5 ℃ accompanied by chills indicates potential severe infection. Progressive dyspnea or coughing with blood, pneumonia should be ruled out. Central nervous system infection manifests as neck stiffness, blurred consciousness, or epileptic seizures, requiring emergency lumbar puncture examination.

(2) Abnormal blood system

Abnormal bleeding such as persistent nosebleeds or subcutaneous bruising indicates thrombocytopenia. Extreme fatigue accompanied by pale complexion may indicate severe anemia. Lymph node enlargement accompanied by weight loss requires exclusion of hematological malignancies.

(3) Allergic reactions

Facial/laryngeal edema accompanied by wheezing sounds requires immediate treatment with adrenaline. Systemic urticaria progresses rapidly and may develop into anaphylactic shock. Sudden drop in blood pressure accompanied by consciousness disorders requires the establishment of venous access for rescue.

3. Special precautions

(1) Hepatitis B virus reactivation

HBsAg positive patients need to undergo antiviral prophylaxis before medication and monitor HBV-DNA monthly. If jaundice or liver enzyme levels increase by more than 5 times, the medication should be stopped immediately.

(2) Progressive multifocal leukoencephalopathy

Manifested as cognitive decline or limb weakness, requiring brain MRI examination. After diagnosis, medication should be discontinued and plasma exchange treatment should be received.

(3) Vaccination contraindications

During the medication period, it is prohibited to receive live vaccines, and inactivated vaccines should be administered during the interval between treatment cycles. The influenza vaccine should be administered 4 weeks before infusion.