Common side effects of dimethyl fumarate in the treatment of multiple sclerosis include flushing, gastrointestinal reactions, and decreased lymphocytes. Most symptoms can be relieved on their own or improved by adjusting the medication regimen. The following provides a systematic explanation of the mechanism of occurrence, clinical manifestations, and response measures.

1. Common side effects and mitigation methods

(1) Flushing reaction

About 40% of patients experience facial flushing and fever, often occurring within 30 minutes after medication. It is recommended to take 325mg aspirin (under the guidance of a doctor) 30 minutes before taking the medication to avoid alcohol and spicy food irritation.

(2) Gastrointestinal symptoms

35-40% of patients experience nausea, diarrhea, or abdominal pain. It should be strictly taken with meals, starting with a dose escalation plan (120mgbid for the first 7 days). Patients with persistent symptoms may temporarily use antiemetic drugs or loperamide.

2. Abnormal laboratory indicators

(1) Decreased lymphocytes

About 30% of patients experience a decrease in lymphocyte count. Baseline and every 6 months testing are required. If it continues to be below 0.5 × 10 ⁹/L, medication should be suspended until recovery is achieved. Avoid contact with infectious sources during treatment.

(2) Abnormal liver function

5-8% of patients experience elevated ALT/AST levels. It is recommended to monitor liver function monthly for 3 months before treatment. If the abnormal value reaches 3 times the upper limit, medication should be stopped for evaluation.

3. Special management measures

(1) Allergy reaction prevention

The incidence of rash is about 8%, and severe cases can progress to vascular edema. Observe for 30 minutes after the first medication and prepare the antihistamine medication. If an itchy rash appears, seek medical attention immediately.

(2) Infection risk control

Avoid receiving live vaccines (such as measles vaccine). Continuous fever or infection symptoms during treatment require timely examination of lymphocyte subsets.