Editing Pharmacology (section)

=== Anticoagulants, Antiplatelets, and Thrombolytics ===

* '''Heparin (unfractionated)''': monitored by aPTT, with a therapeutic target commonly 1.5 to 2.5 times the control value, or by anti-Xa level per facility protocol. Antidote is '''protamine sulfate'''. Watch for heparin-induced thrombocytopenia, an immune reaction in which the platelet count falls, typically 5 to 10 days after exposure, and the patient paradoxically clots. If suspected, stop all heparin including flushes and notify the provider.
* '''Enoxaparin''': low molecular weight heparin, more predictable, usually no routine monitoring, dose-reduced in renal impairment. Same subcutaneous technique points listed above.
* '''Warfarin''': vitamin K antagonist. Monitored by prothrombin time and INR, with a usual therapeutic INR of 2.0 to 3.0 for atrial fibrillation and venous thromboembolism, and 2.5 to 3.5 for a mechanical mitral valve. Onset takes several days, so heparin bridging is common. Antidote is '''vitamin K (phytonadione)'''; fresh frozen plasma or prothrombin complex concentrate is used for urgent reversal. Teach '''consistent''', not zero, intake of vitamin K rich foods such as spinach, kale, broccoli, and Brussels sprouts. Contraindicated in pregnancy. Many interactions, including antibiotics, amiodarone, and NSAIDs.
* '''Direct oral anticoagulants''': apixaban and rivaroxaban (factor Xa inhibitors, reversal agent andexanet alfa) and dabigatran (direct thrombin inhibitor, reversal agent idarucizumab). No routine INR monitoring.
* '''Antiplatelets''': aspirin, clopidogrel, ticagrelor. Bleeding and bruising are the main risks. Clopidogrel effect is reduced by strong CYP2C19 inhibitors such as omeprazole.
* '''Thrombolytics''' (alteplase): dissolve existing clot in acute ischemic stroke, ST elevation myocardial infarction, and massive pulmonary embolism. Absolute exclusions include active internal bleeding, recent intracranial hemorrhage, and recent intracranial or intraspinal surgery. During and after infusion, minimize venipunctures and injections and monitor neurologic status closely.

Universal anticoagulant teaching: use a soft toothbrush and an electric razor, avoid contact sports, report black tarry stools, pink or brown urine, bleeding gums, nosebleeds that will not stop, unusual bruising, or a fall with head strike, and wear medical identification.