In cases of immediate anticoagulation, which medication is typically administered?

In cases requiring immediate anticoagulation, heparin is commonly used due to its rapid onset of action. Heparin, particularly unfractionated heparin, acts quickly to inhibit thrombin and factor Xa in the coagulation cascade, thereby preventing the formation of new clots and the extension of existing ones. This makes heparin the preferred choice in acute situations such as deep vein thrombosis, pulmonary embolism, or during certain cardiac events.

The choice of heparin is particularly advantageous because it can be administered intravenously, allowing for immediate therapeutic effects, which is critical in urgent medical scenarios. Additionally, its effects can be quickly reversed with protamine sulfate if necessary.

Other options like dantrolene are primarily used in the management of malignant hyperthermia, statins are typically used for lipid management and cardiovascular risk reduction, and chloroquine is an antimalarial medication. None of these options provide the immediate anticoagulant effect that heparin does.