Description

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. 
Preservative-Free Heparin Lock Flush Solution in the 100 unit/mL concentration is not recommended 
for use in neonates and infants (see WARNINGS, Use In Neonates and Infants). 

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NDA 17-037/S-158 
Page 30 
Maintenance of Patency of Intravenous Devices 
To prevent clot formation in a heparin lock set or central venous catheter following its proper insertion, 
Preservative-Free 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, Preservative-Free 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. 
Withdrawal of Blood Samples 
Preservative-Free Heparin Lock Flush Solution, USP may also be used after each withdrawal of blood 
for laboratory tests. When heparin would interfere with or alter the results of blood tests, the heparin 
solution should be cleared from the device by aspirating and discarding it before withdrawing the 
blood sample. 
HOW SUPPLIED 
HEP-LOCK U/P (Preservative-Free Heparin Lock Flush Solution, USP) 
10 USP units/mL 
1 mL DOSETTE vials packaged in 25s (NDC 0641-0272-25) 
100 USP units/mL 
1 mL DOSETTE vials packaged in 25s (NDC 0641-0273-25)