BACKGROUND: At present, as a therapeutic drug mainly for reducing fibrinogen (FIB) levels, the dynamic influence of defibrase on the FIB levels of patients with acute cerebral infarction has not been clearly ascertained. OBJECTIVE: To observe the dynamic changes in FIB levels of patients with acute cerebral infarction at different time points after taking defibrase. DESIGN, TIME AND SETTING: Randomized controlled clinical trial. The study was conducted in the Department of Neurology, the Second Affiliated Hospital of Jinan University, from June to November 2006. PARTICIPANTS: Sixty patients with acute cerebral infarction, who had been treated by the Neurological Department of the Second Affiliated Hospital of Jinan University from June to November 2006, were selected, including 37 males and 23 females, aged 35–75 years. All cases met the diagnostic criteria formulated by the Fourth National Cerebrovascular Disease Conference within 12 hours of onset. All the patients were confirmed with definite hemiparesis and cerebral infarction without coma, and were randomly divided into two groups: a treatment group (n =40) and a control group (n =20). Patients’ families had the right to be informed and agree with the treatment, which had permission from the Hospital Ethics Committee. METHODS: Patients in the control group were given routine treatment with 30 mL fleabane and 0.75 g cytidine diphosphate added to 500 mL saline solution once a day for 14 consecutive days. Patients in the treatment group were given routine treatment and Haiwang defibrase injection (purchased from Changchu Guoao Bio-Pharmaceutical Co. Ltd., Approval document number H10983237) within 12 hours of infarction. Defibrase doses of 15, 12.5 and 10 U were given over 2 hours according to the patients’ pre-treatment plasma FIB levels of ≥ 4.50 g/L, 3.50-4.49 g/L and 1.00-3.49 g/L, respectively. Plasma FIB levels in the treatment group were measured before, and once every six hours for 48 hours after administration of defibrase. Later, measurements were taken once every 12 hours and FIB levels were kept in a range of 0.5–1.3 g/L for one week. When the FIB level increased to over 1.3 g/L, a 5 U dose of defibrase was given again over two hours. FIB levels of the control group were measured once before treatment and once after one week of treatment MAIN OUTCOME MEASURES: (1) Dynamic changes of FIB levels in the defibrase treatment group. (2) Comparison of dynamic changes of FIB levels in the treatment group and control group before and after treatment for one week. RESULTS: All 60 patients were included in the final analysis. The treatment group’s FIB levels quickly decreased to 0.5–1.3 g/L within 12 hours of taking the first dose of defibrase and reached a minimum in 24 hours. Later, they began to rise slowly into the therapeutic range (0.5–1.3 g/L) in 48 hours. The FIB levels of the treatment group increased slowly to over 1.3 g/L in 60 hours after the first dose of defibrase and then quickly decreased to the therapeutic range after the second dose of 5 U defibrase with a minimum level higher than after the first dose, and higher again after the third dose. After treatment, patients’ FIB levels could be kept in the therapeutic range for about one week. The FIB levels in patients in the treatment group were significantly lower after taking defibrase for one week in comparison with the levels before treatment (P < 0.01). There was no difference in the control group between the levels pre-treatment and one week after treatment (P > 0.05). CONCLUSIONS: FIB levels in patients with acute cerebral infarction quickly decrease after taking the first dose of defibrase and reach a minimum in 24 hours. Later, they begin to rise slowly into the therapeutic range (0.5–1.3 g/L) in 48 hours. The FIB levels increase slowly to over 1.3 g/L in 60 hours. The effect of defibrase is weaker when the same dose of defibrase is used in patients repeatedly. BACKGROUND: At present, as a therapeutic drug mainly for reducing fibrinogen (FIB) levels, the dynamic influence of defibrase on the FIB levels of patients with acute cerebral infarction has not been clearly ascertained. OBJECTIVE: To observe the dynamic changes in FIB levels of patients with acute cerebral infarction at different time points after taking defibrase. DESIGN, TIME AND SETTING: Randomized controlled clinical trial. The study was conducted in the Department of Neurology, the Second Affiliated Hospital of Jinan University, from June to November 2006. PARTICIPANTS: Sixty patients with acute cerebral infarction, who had been treated by the Neurological Department of the Second Affiliated Hospital of Jinan University from June to November 2006, were selected, including 37 males and 23 females, aged 35-75 years. All cases met the diagnostic condition formulated by the Fourth National Cerebrovascular Disease Conference within 12 hours of onset. All the patients were confirmed w ith definite hemiparesis and cerebral infarction without coma, and were randomly divided into two groups: a treatment group (n = 40) and a control group (n = 20). Patients’ families had the right to be informed and agree with the treatment, METHODS: Patients in the control group were given routine treatment with 30 mL fleabane and 0.75 g cytidine diphosphate added to 500 mL saline solution once a day for 14 consecutive days. Patients in the treatment group were given routine treatment and Haiwang defibrase injection (purchased from Changchu Guoao Bio-Pharmaceutical Co. Ltd., Approval document number H10983237) within 12 hours of infarction. Defibrase doses of 15, 12.5 and 10 U were given over 2 hours according to the patient ’pre -treatment plasma FIB levels of ≥ 4.50 g / L, 3.50-4.49 g / L and 1.00-3.49 g / L, respectively. Plasma FIB levels in the treatment group were measured before, and once every six hours for 48 hours after a dministrAfter the FIB levels were kept in a range of 0.5-1.3 g / L for one week. When the FIB levels increased to over 1.3 g / L, a 5 U dose of defibrase FIB levels of the control group were measured once before treatment and once after one week of treatment MAIN OUTCOME MEASURES: (1) Dynamic changes of FIB levels in the defibrase treatment group. (2) Comparison of dynamic changes of FIB levels in the treatment group and control group before and after treatment for one week. RESULTS: All 60 patients were included in the final analysis. The treatment group’s FIB levels quickly decreased to 0.5-1.3 g / L within 12 hours of taking the first dose of defibrase and reached a minimum in 24 hours. Later, they began to rise slowly into the therapeutic range (0.5-1.3 g / L) in 48 hours. The FIB levels of the treatment group increased slowly to over 1.3 g / L in 60 hours after the first dose of defibrase and the ntening decreased to the second dose of 5 U defibrase with a minimum level higher than after the first dose, and higher again after the third dose. After treatment, patients’ FIB levels could be be kept in the therapeutic range for about one week. The FIB levels in patients in the treatment group were significantly lower after taking defibrase for one week in comparison with the levels before treatment (P <0.01). There was no difference in the control group between the levels pre-treatment and one week after treatment (P> 0.05). CONCLUSIONS: FIB levels in patients with acute cerebral infarction quickly decrease after taking the first dose of defibrase and reach a minimum in 24 hours. Later, they begin to rise slowly into the therapeutic range (0.5- The Fib levels increase slowly to over 1.3 g / L in 60 hours. The effect of defibrase is weaker when the same dose of defibrase is used in patients repeatedly.