Blood Coagulation Tests

Male Sprague-Dawley rats weighing 200-220 g receive the test compound or the vehicle (controls) by 

Based on the contributions by M. Just and V. Laux in the book H.G. Vogel (ed) (2002) Drug Discovery and Evaluation - Pharmacological Assays , Springer-Verlag, second edition. 

In general, citrated plasma is coagulated by the addition of the respective compounds (see below) and the time to clot formation is determined in the coagulome-ter (= coagulation time). 

For detailed laboratory diagnosis of bleeding disorders and assessment of blood coagulation see Palmer (1984) and Nilsson (1987). 

Activated Partial Thromboplastin Time (APTT). To 0.1 ml of citrated plasma 0.1 ml of human placenta lipid extract (Pathrombin, Behring Werke, Marburg) is added and the mixture is incubated for 2 min at 37 °C. The coagulation process is initiated by the addition of 0.1 ml 25 mM calcium chloride when the coagulometer is started and the time to clot formation is determined. The APTT measures effects on the endogenous pathway of coagulation. 

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Blood coagulation tests are usually ordered before and during heparin tiierapy, and die dose of heparin is adjusted to die test results. Optimal results of therapy are obtained when the APTT is 1.5 to 2.5 times the control value The LMWHs do not require close monitoring of blood coagulation tests. 

Blood coagulation tests for those receiving heparin by continuous IV infusion are taken at periodic intervals (usually every 4 hours) determined by the primary health care provider. If the patient is receiving long-term heparin therapy, blood coagulation tests may be performed at less frequent intervals... 

If administration of this drug is necessary, the nurse monitors the patient s blood pressure and pulse rate every 15 to 30 minutes for 2 hours or more after administration of the heparin antagonist. The nurse immediately reports to the primary health care provider any sudden decrease in blood pressure or increase in the pulse rate The nurse observes the patient for new evidence of bleeding until blood coagulation tests are within normal limits. To replace blood loss, the primary health care provider may order blood transfusions or fresh frozen plasma... 

Hypersensitivity to heparin severe thrombocytopenia uncontrolled bleeding (except when it is due to DIG) any patient for whom suitable blood coagulation tests cannot be performed at the appropriate intervals (there is usually no need to monitor coagulation parameters in patients receiving low-dose heparin). 

I.M.1.1 Blood Coagulation Tests 256 in Canine Coronary Artery ... 

No changes in INR (a standardized scale used to report the results of blood coagulation tests), platelet aggregation, clotting factor activity, or plasma levels of warfarin, were observed in healthy volunteers orally administered two garlic tablets (each the equivalent of 2 g fresh garlic) daily for two weeks (Abdul et al. 2008). 

Decreased INR (international normalized ratio, a system used to report the results of blood coagulation tests) was reported in a patient taking warfarin and drinking... 

One case report indicated increased INR (a standardized scale used to report the results of blood coagulation tests increased INR indicates slowed blood clotting) in a woman previously stable on warfarin who drank lycium fruit tea for several days. After cessation of the tea, INR levels returned to normal (Lam et al. 2001). The woman was also taking other drugs, at least one of which has been associated with increased INR levels in persons on warfarin (Trilli et al. 1996). 

Decreased international normalized ratio (INR) (a standardized scale used to report the results of blood coagulation tests) was reported in a patient taking warfarin and other prescription drugs for cardiovascular conditions (Janetzky and Morreale 1997). Thrombosis of a prosthetic aortic valve and a decrease in INR were reported in a patient taking warfarin and ginseng (species and dose unspecified). The patient had a history of erratic INR levels (Rosado 2003). 

History of cardiac and/or hepatorenal disease. Prior to treatment, laboratory studies including blood pressure, complete blood counts, serum electrolytes, blood coagulation tests, fiver function tests, urinalyses, chest X-rays, and electrocardiography are required. 

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