Description

Treatment—Neutralization Of Heparin Effect 
When clinical circumstances (bleeding) require reversal of heparinization, protamine sulfate (1
% 
solution) by slow infusion will neutralize heparin sodium. No more than 50 mg should be 
administered, very slowly, in any 10-minute period. Each mg of protamine sulfate neutralizes 
approximately 100 USP heparin units. The amount of protamine required decreases over time as 
heparin is metabolized. Although the metabolism of heparin is complex, it may, for the purpose of 
choosing a protamine dose, be assumed to have a half-life of about 
1
/
2
hour after intravenous injection. 

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NDA 17-037/S-158 
Page 20 
Administration of protamine sulfate can cause severe hypotensive and anaphylactoid reactions. 
Because fatal reactions often resembling anaphylaxis have been reported, the drug should be given 
only when resuscitation techniques and treatment of anaphylactoid shock are readily available. 
For additional information consult the labeling of Protamine Sulfate Injection, USP products. 
DOSAGE AND ADMINISTRATION 
Parenteral drug products should be inspected visually for particulate matter and discoloration 
prior to administration, whenever solution and container permit. Slight discoloration does not 
alter potency. 
Heparin Lock Flush Solution is not recommended for use in neonates (see WARNINGS, Use In 
Neonates). 
Maintenance Of Patency Of Intravenous Devices 
To prevent clot formation in a heparin lock set or central venous catheter following its proper insertion, 
Heparin Lock Flush Solution, USP is injected via the injection hub in a quantity sufficient to fill the 
entire device. This solution should be replaced each time the device is used. Aspirate before 
administering any solution via the device in order to confirm patency and location of needle or catheter 
tip. If the drug to be administered is incompatible with heparin, the entire device should be flushed 
with normal saline before and after the medication is administered; following the second saline flush, 
Heparin Lock Flush Solution, USP may be reinstilled into the device. The device manufacturer's 
instructions should be consulted for specifics concerning its use. Usually this dilute heparin solution 
will maintain anticoagulation within the device for up to 4 hours. 
NOTE: Since repeated injections of small doses of heparin can alter tests for activated partial 
thromboplastin time (APTT), a baseline value for APTT should be obtained prior to insertion of an 
intravenous device.