6,502
edits
Changes
Jump to navigation
Jump to search
Anticoagulant Rodenticide Toxicity (view source)
Revision as of 12:35, 23 August 2010
, 12:35, 23 August 2010→Description
Line 38:
Line 38:
during the coagulation process and thus cannot
during the coagulation process and thus cannot
actively participate in fibrin formation.
actively participate in fibrin formation.
+
+
+Warfarin and similar compounds interfere with the regeneration of vitamin K from an intermediate formed during the action
+of vitamin K as an essential co-factor in the production of several of the factors involved in the clotting cascade. This is by competitive
+inhibition of the enzyme involved in the regenerative process and leads to a reduction in available vitamin K, thereby resulting
+in defective blood clotting. Vitamin K dependent clotting factors are VII, IX, 11 and X so the intrinsic pathway (activated by blood
+vessel injury), the extrinsic pathway (activated by tissue injury) and the final common pathway (with conversion of prothrombin
+to thrombin, formation of fibrin and stabilisation of the platelets) is affected. However, the primary haemostatic response (formation
+of platelet plug) is unaffected.
+Increased blood vessel fragility also appears to be a result of coumarin toxicity and may account for bleeding at sites that are
+not subject to external trauma.
+Following absorption, coumarins are carried bound to plasma albumin. Therefore, effects are potentiated by drugs that are also
+bound to albumin such as phenylbutazone, or conditions that result in low plasma albumin levels such as renal insufficiency.
==Signalment==
==Signalment==