Effects of acute and chronic exposure to secobarbital on the activity of hepatic synthesized clotting factors.

Male Sprague-Dawley rats were injected with either a single subcutaneous dose of 75 mg of secobarbital, or once daily injections of 20 mg of secobarbital for 7 days. Plasma was collected prior to treatment and 18 hours later (75 mg) or 8 and 15 days later (20 mg). Plasma was analyzed for the platelet count (PLT), prothrombin time (PT), fibrinogen (FIB), and coagulation factor activities for factors II, V, VII, IX, and X. Treatment with a single subcutaneous injection of 75 mg of secobarbital caused statistically significant alterations in every clotting activity measured whereas 7 days of treatment with 20 mg once daily resulted in only 2 clotting factors being abnormal. These two factors returned to pretreatment levels following 7 days of withdrawal of secobarbital. The data indicates that a single larger dose of secobarbital is more influential on hepatic synthesized clotting factor activity than is longer treatment with a lesser dose.