Heparin overdose

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. 

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. 

Indications Heparin overdose Category Heparin antagonist Half-life 2 hours... 

Protamine sulfate, a heparin antagonist, is used in heparin overdose (see also Table 17). 

Similarly, let s imagine that a patient dies of a heparin overdose and the incident investigation finds that the heparin for her IV flush had been kept at the bedside along with her IV push... 

The IV heparin overdose example illustrates another important point if, on this unit, IV push medications are frequently kept at bedside, it means that this practice has become a part of the unit s culture. And that means that local unit leadership has tacitly accepted the hazard. If an exposure occurs with some regularity, it becomes a part of the culture and is regarded by those laboring at the bedside as accepted by the leadership. 

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. 

Glyceryl trinitrate overdose should be treated with the patient s head lowered. Other measures include respiration maintenance, use of plasma expanders, and electrolyte balance. Withdrawal of heparin treatment or dose reduction should be performed with the overdose of heparin. Protamine sulfate may be used to reduce severe bleeding. Heparin should be used with caution with glyceryl trinitrate, aprotinine, alcohol, tobacco, and ACE inhibitors. Nifedipine should be used with care when coadministering with immunosuppressants, magnesium salts, tobacco, digoxin, antineoplastics, calcium channel blockers, antihistamines, antifungals, antiepileptics, antiarrhythmics, and alcohol. 

Allergic reaction due to streptokinase overdose should be treated with corticosteroids and histamines. Severe hemorrhage requires discontinuation of streptokinase. Packed red blood cells are preferable for blood-replacement therapy, and volume expansion is advisable. Streptokinase may be used with caution with heparin, allopurinol, sex hormones, sulfonamides, tetracyclines, and dextran. 

This is the antidote for heparin, but the nurse would not administer this first. Discontinuing the infusion of heparin for a few hours may be sufficient to correct the overdose. 

C. If the patient is overdosed with an unknown quantity of heparin, then give an empiric dose of 25-50 mg over 15 minutes (to minimize hypotension) and de-tennine the activated partial thromboplastin time (aPTT) after 5-15 minutes and for up to 2-8 hours to detemiine need for additional doses. 

The whole content of a vial containing 125 000 international units of heparin was prepared as a continuous infusion, resulting in a 5 times overdose to a patient on a general medical ward in a teaching hospital. 

Comment Haemorrhage is one of the serious, potentially life threatening complication of an overdose of heparin. 

Sulfation is the primary conjugation reaction for substrates with phenol groups or aliphatic alcohols (Sturgill and Lambert, 1997 Brown, 2001). These reactions are catalyzed by sulfotransferases in the cytoplasm. Agents that undergo sulfation include acetaminophen, morphine, ascorbic acid, and endogenous compoimds like chondroitin, heparin, and some steroids. The pool of available sulfates may become saturated in drug overdoses. 

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