What is the Difference Between Heparin and Alteplase

The key difference between Heparin and Alteplase is that Heparin prevents the further growth of existing blood clots and the formation of new ones by binding to antithrombin III, inhibiting the activity of several clotting factors, while Alteplase breaks down existing blood clots by converting plasminogen into plasmin, an enzyme that can dissolve fibrin.

Heparin and Alteplase are commonly used anticoagulants used to treat blot clots. Heparin is a blood thinner that prevents blood clots from forming. It does this by inhibiting thrombin. Heparin is typically used to treat or prevent blood clots in medical procedures and conditions like surgeries, pulmonary embolisms, and venous thrombosis. Alteplase is a thrombolytic medication that dissolves blood clots by breaking down fibrin. It is typically used to reduce mortality and incidence of heart failure associated with acute ischemic stroke, acute myocardial infarction, and pulmonary emboli. Both medications can be administered intravenously. The best medication for each will depend on their medical condition and the type of blood clot they have. Heparin or Alteplase may be used if the blood clot is in a vein. If the blood clot is in an artery, Alteplase is typically the preferred medication.

CONTENTS

1. Overview and Key Difference
2. What is Heparin  
3. What is Alteplase
4. Similarities – Heparin and Alteplase
5. Heparin vs. Alteplase in Tabular Form
6. Summary – Heparin vs. Alteplase

What is Heparin?

Heparin naturally occurs in various cells, such as the liver, lung, and mast cells, inhibiting the reactions leading to blood clotting. It is primarily used for preventing and treating blood clots in various medical procedures and conditions, including surgeries, pulmonary embolisms, and venous thrombosis. Heparin reversibly interacts with antithrombin III, preventing blood clotting by inactivating coagulation enzymes such as thrombin and factor Xa to prevent the conversion of fibrinogen to fibrin. Furthermore, Heparin also inhibits stable fibrin-stabilizing factors, preventing stable fibrin clot formation. It is a preparation of sulfated glycosaminoglycan with anionic properties and a molecular weight ranging from 3 kDa to 30 kDa.

Heparin is generally administered through parental routes, such as intravenously. The peak plasma concentration is achieved immediately after the administration. It is neither administered orally nor intramuscularly. The plasma half-life of Heparin is dose-dependent. When administered intravenously, it is approximately 30 minutes. Heparin is bound with plasma proteins such as antithrombin, fibrinogens, globulins, serum proteases, and lipoproteins during transportation. It does not undergo enzymatic degradation and is rapidly eliminated in the urine. Heparin has been shown to decrease calcium levels, so administration of calcium supplements may be necessary. It is advised to avoid herbs and other supplements that have anticoagulant effects.

What is Alteplase?

Alteplase is a recombinant human tissue plasminogen activator primarily used as a thrombolytic agent. In commercial Alteplase isolation, the protein is expressed in Chinese hamster ovary (CHO) cells and then purified. It is prescribed to reduce mortality and incidence of heart failure associated with acute ischemic stroke, acute myocardial infarction, and pulmonary emboli. Alteplase degrades the fibrin clots by cleaving plasminogen into plasmin in a fibrin-dependent manner. Alteplase can only convert a limited amount of plasminogen when fibrin is absent. However, when fibrin clots are present, Alteplase binds to fibrin and cleaves the arginine-valine bonds of plasminogen, converting it into plasmin – the active form. Plasmin, in turn, dissolves the fibrin matrix of the thrombus, promoting clot dissolution.

Alteplase is also administered intravenously and distributed to the central compartments with a volume of distribution of 3.9 L to 4.3 L. It is mainly metabolized in the liver and follows a zero-order kinetics. Over 80% of the unmetabolized Alteplase is eliminated in the urine 18 hours after administration. The plasma half-life of Alteplase is 3 hours. The overdose of Alteplase may increase the risk of bleeding and thromboembolic events.

What are The Similarities Between Heparin and Alteplase?

• Heparin and Alteplase are used to treat blood clots.
• Both medications can be administered intravenously.
• They can cause side effects such as bleeding, nausea, and vomiting.
• Both medications should be used cautiously in people with bleeding disorders and liver and kidney diseases.

What is the Difference Between Heparin and Alteplase?

Heparin and Alteplase are commonly used to prevent blood clot formation. Despite having similar clinical implications, there is a difference between Heparin and Alteplase. Heparin works by inhibiting the formation of blood clots, mainly the further growth of existing blood clots and the formation of new ones. Alteplase, on the other hand, works by breaking down existing blood clots. Heparin binds to antithrombin III, which in turn inhibits the activity of several clotting factors, including thrombin and factor Xa. In contrast, Alteplase is a tissue plasminogen activator (tPA) that converts plasminogen into plasmin, an enzyme that can dissolve fibrin, the protein that makes up blood clots through fibrinolysis.

Heparin is typically indicated for various medical procedures and conditions, such as surgeries, pulmonary embolisms, and venous thrombosis. In comparison, Alteplase is typically indicated to reduce the mortality and incidence of heart failure associated with acute ischemic stroke, myocardial infarction, and pulmonary emboli. Overall, Alteplase is significantly more effective than Heparin in preventing blood clot formation.

Below is a summary of the difference between Heparin and Alteplase in tabular form for side-by-side comparison.

Summary – Heparin vs. Alteplase

Heparin and Alteplase are two medications with distinct mechanisms of action and therapeutic indications in the management of blood clots. Heparin primarily helps to prevent the formation of new clots and further growth of existing ones by inhibiting clotting factors, while Alteplase is used to actively dissolve existing blood clots by converting plasminogen into plasmin. There is also a difference between Heparin and Alteplase in terms of metabolism and effectiveness. Heparin does not undergo enzymatic metabolism, and Alteplase is metabolized extensively in the liver. Additionally, Alteplase is considered more effective in dissolving existing clots compared to Heparin. Ultimately, the choice between Heparin and Alteplase depends on the specific medical condition and the therapeutic goal, and it should be made in consultation with a healthcare professional. Both medications have their own unique applications and considerations in the management of clot-related disorders.

Reference:

1. Gittins, N. S, et al. “Comparison of alteplase and heparin in maintaining the patency of paediatric central venous haemodialysis lines: A randomized controlled trial.” Archives of Disease in Childhood, vol. 92, no. 6, 2007, pp.
2. Oduah, Eziafa, et al. “Heparin: Past, present, and future.” Pharmaceuticals, vol. 9, no. 3, 2016, p. 38.

Image Courtesy:

1. “Heparin-General-Structure” By Jü – Own work (CC0) via Commons Wikimedia