<prompt> Antidote of heparin isCaNaEDTAProtamine sulfateDeferiproned - penicillamine  <response>: Ans. is b i.e., Protamine sulfate Protamine sulfate It is a strongly basic, low molecular weight protein obtained from the sperm of certain fish. Given i. v. it neutralizes heparin weight for weight, i.e., 1 mg is needed for every 100 U of heparin. It is needed only when the heparin action needs to be terminated rapidly, e.g., after cardiac or vascular surgery. In absence of heparin, protamine itself acts as a weak anticoagulant by interacting with platelets and fibrinogen. 