Heparin antidote

Soon after the initial development of the heparin sensor, an electrode for the detection of the polycation protamine was proposed [38] based on a polymeric membrane doped with the cation exchanger tetrakis-(4-chlorophenyl)borate. Protamine is a polypeptide and usually administered as a heparin antidote. Protamine is a polycation with an average charge of +20 and is rich in arginine (Fig. 4.8). The response function of protamine-selective electrodes is similar to the heparin response function (Fig. 4.9b). 

Propylthiouracil (PTU) Anti-thyroid Protamine (Protamine) Heparin antidote... 

The numerous negative charges are significant in several respects (1) they contribute to the poor membrane penetrability—heparin is ineffective when applied by the oral route or topically onto the skin and must be injected (2) attraction to positively charged lysine residues is involved in complex formation with ATIII (3) they permit binding of heparin to its antidote, protamine (polycationic protein from salmon sperm). 

Antidote Protamine sulfate 1-1.5 mg, IV, for every 100 units heparin subcutaneous within 30 min of overdose, 0.5-0.75 mg for every 100 units heparin subcutaneous if within 30-60 min of overdose, 0.25-0.375 mg for every 100 units heparin subcutaneous if 2 hr have elapsed since overdose, 25-50 mg if heparin was given by IV infusion. 

Heparin overdose (antidote and treatment) IV 1-1.5 mg protamine neutralizes 100 units heparin. Heparin disappears rapidly from circulation, reducing the dosage demand for protamine as time elapses. 

The use of unfractionated heparin has been optimized by the development of the LMWHs. This is primarily due to our current understanding of the chemistry and biology of heparin. Antithrombin drugs such as hirudin, argatroban, and bivalirudin have been in development for many years. These drugs are useful as substitutes for heparin in such conditions as heparin-induced thrombocytopenia however, these drugs do not have an antidote and cannot be used for surgical indications at... 

In summary, bivalirudin use during PPI is safe and may prove to have an advantage over heparin. However, we caution the use of bivalirudin during PPI procedures attempting to cross and treat chronic total occlusions where the risk of perforation is substantial with an indication for immediate reversal of anticoagulation. There is no known antidote to bivalirudin. 

Hirudin, a polypeptide originally isolated from the salivary glands of the medicinal leech Hirudo medicalis, is now produced by recombinant technology. It is a potent and specific inhibitor of thrombin with which it forms an almost irreversible complex. It is cleared predominantly by the kidneys and has a of 40 minutes after i.v. administration. No antidote is available for a bleeding patient. It has been used successfully in patients with heparin-induced thrombocytopenia (HIT), thromboprophylaxis in elective hip arthroplasty, xmstable angina and myocardial infarction. 

There is currently no specific antidote for fondaparinux it is not neutralized by protamine sulfate. Fondaparinux shows no cross-reactivity with antibodies associated with heparin-induced thrombocytopenia. 

Protamine Sulfate, U5P. Protamine sulfate has an anticoagulant effect, but if used in the proper amount, it counteracts the action of heparin and is u.sed as an antidote for the latter in ca.ses of overdosage. It is administered intravenously in a dose that depends on the circumstances. 

Protamine can be used as an antidote in heparin overdose. Etham late reduces capillary bleeding, and is used in the treatment of menorrhagia and probably works by correcting impaired platelet adhesion. 

Low molecular weight heparins (LMWHs) (antidote is protamine sulfate given IV)... 

The primary adverse effect associated with fondaparinux therapy is bleeding." " The rate of major bleeding in the VTE prophylaxis trials was approximately 2% to 3%. The risk of major bleeding appears to be related to weight therefore, in patients who weigh less than 50 kg, fondaparinux is contraindicated for VTE prophylaxis, and the treatment dose is only 5 mg every 24 hours. Similar to UFH and the LMWHs, fondaparinux should be used with extreme caution in patients with neuraxial anesthesia or following a spinal puncture owing to the risk for spinal or epidural hematoma formation. Unlike UFH and the LMWHs, fondaparinux does not cause heparin-induced thrombocytopenia and does not produce cross-sensitivity in vitro." A specific antidote to reverse the antithrombotic activity of fondaparinux is not currently available, but several potential products have been evaluated. 

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