Heparin instructions for administration

Heparin Dosage and Administration

When Heparin is added to an infusion solution for continuous intravenous administration, the container should be inverted at least six times to insure adequate mixing and prevent pooling of the Heparin in the solution.

Heparin sodium is not effective by oral administration and should be given by intermittent intravenous injection, intravenous infusion, or deep subcutaneous (intrafat, i.e., above the iliac crest or abdominal fat layer) injection. The intramuscular route of administration should be avoided because of the frequent occurrence of hematoma at the injection site.

The dosage of Heparin sodium should be adjusted according to the patient’s coagulation-test results. When Heparin is given by continuous intravenous infusion, the coagulation time should be determined approximately every 4 hours in the early stages of treatment. When the drug is administered intermittently by intravenous injection, coagulation tests should be performed before each injection during the early stages of treatment and at appropriate intervals thereafter. Dosage is considered adequate when the activated partial thromboplastin time (APTT) is 1.5 to 2 times normal or when the whole blood clotting time is elevated approximately 2.5 to 3 times the control value. After deep subcutaneous (intrafat) injections, tests for adequacy of dosage are best performed on samples drawn 4 to 6 hours after the injections.

Periodic platelet counts, hematocrits, and tests for occult blood in stool are recommended during the entire course of Heparin therapy, regardless of the route of administration.

Heparin Sodium Injection should not be mixed with doxorubicin, droperidol, ciprofloxacin, or mitoxantrone, since it has been reported that these drugs are incompatible with Heparin and a precipitate may form.

Converting to Oral Anticoagulant

When an oral anticoagulant of the coumarin or similar type is to be begun in patients already receiving Heparin sodium, baseline and subsequent tests of prothrombin activity must be determined at a time when Heparin activity is too low to affect the prothrombin time. This is about 5 hours after the last IV bolus and 24 hours after the last subcutaneous dose. If continuous IV Heparin infusion is used, prothrombin time can usually be measured at any time.

In converting from Heparin to an oral anticoagulant, the dose of the oral anticoagulant should be the usual initial amount, and thereafter prothrombin time should be determined at the usual intervals. To ensure continuous anticoagulation, it is advisable to continue full Heparin therapy for several days after the prothrombin time has reached the therapeutic range. Heparin therapy may then be discontinued without tapering.

Therapeutic Anticoagulant Effect With Full-Dose Heparin