2. Clinical manifestations

(1) Patients with mild acute poisoning showed nystagmus, dizziness, unsteady gait, ataxia and mental abnormality. In severe cases, high fever, dilated pupils, sinus bradycardia, high atrioventricular block, hunchback, blood pressure drop, coma and respiratory depression may occur.

(2) Chronic poisoning can cause brain atrophy, manifested as nystagmus, finger tremor, ataxia and slurred speech. Often accompanied by gingival hyperplasia. Some patients may have fever, jaundice, myocardial injury, allergic skin rash's disease, exfoliative dermatitis, chronic lymphoma, hirsutism, purpura, anemia, leukopenia and eosinophilia. Occasionally peripheral neuritis, proteinuria, porphyria, etc.

(3) Gastrointestinal reactions are the most common adverse reactions, such as nausea, vomiting and abdominal pain, and others include headache, dizziness, fatigue, drowsiness, dry skin or rash.

3. Determination of blood drug concentration. The therapeutic concentration is 10 ~ 20mg/L, which means severe poisoning >; 40 mg/L & gt95 mg/L can be fatal. Due to the influence of plasma protein content and taking drugs at the same time, the correlation between blood drug concentration and clinical symptoms is not significant.