Heparin treatment is monitored by:

Ans: A (aPTT) Ref: The Pharmacological basis of therapeutics by Good man & Gilman - 12th edition, page no. 855-857Explanation:Heparin treatment is monitored using activated partial thromboplastin time (aPTT)An aPTT two to three times the normal mean aPTT value generally is therapeutic.Prothrombin time (International Normalized Ratio) is used to monitor warfarin therapy.The low molecular weight heparin such as enoxaparin and tinzaparin and fondaparinux do not require aPTT monitoring as with unfractionated heparin. Hence they can be administered even for out-of -hospital management.Another advantage with LMYV heparin is that they can be given by subcutaneous injection once or twice daily.Heparin and fondaparinux are mainly used in the treatment and prevention of venous thromboembolism.Fondaparinux is a factor Xa inhibitor, which also has the same advantages of LMW - subcutaneous injection, no need of lab monitoring.Fondaparinux should not be used in the setting of angioplasty as it has a greater risk of catheter thrombosis.Anticoagulation ibn pregnancy is best managed with UFH, LMW heparin and fondaparinux since they do not cross placenta to cause fetal malformations as seen with warfarin.Fondaparinux is least likely to cause thrombocytopenia among the anti-coagulants.Heparin is preferred in CABG surgery since protamine sulfate can be used to neutralize its effects following procedure.