Page 124 - Pharmd general phytochemistry I-Final2024_LEUCTERS

 Heparin exists as the anion at physiologic pH and is usually administered as the
sodium salt.

 Heparin acts as an anticoagulant by combining with antithrombin III, an α-
glycoprotein, which is synthesized in the liver.

 The heparin-antithrombin III complex inactivates factor Xa and therefore inhibits
the generation of thrombin.

Uses:
 It is believed that heparin to be the anticoagulant of choice, but parenteral

administration precludes its long-term use.
 Heparin is generally given to postoperative patients and to those with acute

infarctions requiring immediate anticoagulant activity.
Doses:
 5,000-10,000 USP units every 4 hours.
Rout of administration:
 Heparin is administered intravenously in two ways:
1- The intermittent dose method.
2- The continuous drip method. The flow in the second adjusted according to the
observed clotting.
 If hemorrhage occurs, the anticoagulant effects of heparin can be reversed in

minutes by the administration of protamine sulfate.

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