What is the appropriate dosing for a Heparin (unfractionated heparin) infusion?

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Last updated: March 30, 2025View editorial policy

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From the Guidelines

Heparin drip dosing should be initiated with a bolus of 60 U/kg followed by an initial infusion rate of 12 U/kg per hour, with a maximum of 4000 U bolus and 1000 U/h initial infusion for patients weighing greater than 70 kg, and adjusted to maintain activated partial thromboplastin time (aPTT) at 1.5 to 2.0 times control (approximately 50 to 70 seconds) 1. The dosing protocol is based on the patient's weight, and the initial infusion rate should be adjusted according to the aPTT results.

  • The target aPTT range is usually between 1.5 to 2.0 times the control value, which is approximately 50 to 70 seconds 1.
  • For patients undergoing reperfusion therapy with streptokinase, it may be reasonable to administer UFH intravenously 1.
  • Regular monitoring of aPTT and platelet counts is essential to balance anticoagulation efficacy against bleeding risk, with platelet counts monitored daily in patients given UFH 1.
  • The dose of heparin may need to be adjusted based on the patient's renal function, age, weight, and bleeding risk.
  • Heparin works by binding to antithrombin III, enhancing its ability to inactivate several coagulation factors including thrombin and factor Xa.
  • The recommended weight-adjusted dose of UFH, when it is administered without fibrinolytics, is 60 to 70 U/kg IV bolus and 12 to 15 U/kg per hour infusion 1.

From the FDA Drug Label

2.3 Therapeutic Anticoagulant Effect with Full-Dose Heparin The dosing recommendations in Table 1 are based on clinical experience be adjusted for the individual patient according to the results of suitable laboratory tests, the following dosage schedules may be used as guidelines: Table 1: Recommended Adult Full-Dose Heparin Regimens for Therapeutic Anticoagulant Effect *Based on 68 kg patient METHOD OF ADMINISTRATION FREQUENCY RECOMMENDED DOSE Continuous Intravenous Infusion Initial Dose 5,000 units by intravenous injection Continuous 20,000 to 40,000 units/24 hours in 1,000 mL of 0.9% Sodium Chloride Injection, USP (or in any compatible solution) for infusion

The recommended adult full-dose heparin regimen for therapeutic anticoagulant effect via continuous intravenous infusion is:

  • Initial dose: 5,000 units by intravenous injection
  • Continuous infusion: 20,000 to 40,000 units/24 hours in 1,000 mL of 0.9% Sodium Chloride Injection, USP (or in any compatible solution) for infusion 2

From the Research

Heparin Drip Dosing

  • Heparin drip dosing is not directly addressed in the provided studies, which primarily focus on argatroban and its use in patients with heparin-induced thrombocytopenia (HIT) or HIT with thrombosis (HITTS) 3, 4, 5, 6, 7.
  • However, the studies discuss the management of patients with HIT or HITTS, including the use of alternative anticoagulants such as argatroban, and the monitoring of activated partial thromboplastin time (aPTT) levels 3, 4, 5, 6.
  • Argatroban is administered by continuous infusion, with a recommended initial dose of 2 microg/kg per min, to achieve aPTT levels 1.5-3.0 times baseline 4, 5.
  • The effectiveness of argatroban in managing HIT or HITTS has been evaluated in several studies, with results showing reduced incidence of thrombotic events and bleeding complications 5, 6, 7.
  • A Bayesian network meta-analysis found that argatroban performed better overall for selected patients with HIT, with shorter hospitalization length, and lower rates of haemorrhages, thromboembolisms, and mortality compared to other anticoagulants 7.

Key Findings

  • Argatroban is a suitable alternative anticoagulant for patients with HIT or HITTS 3, 4, 5, 6, 7.
  • Monitoring of aPTT levels is crucial in managing patients with HIT or HITTS 3, 4, 5, 6.
  • Standardized protocols for managing HIT or HITTS can improve patient outcomes 6.

Study Limitations

  • The studies primarily focus on argatroban and its use in patients with HIT or HITTS, with limited information on heparin drip dosing 3, 4, 5, 6, 7.
  • Further research is needed to evaluate the effectiveness of standardized protocols for managing HIT or HITTS 6.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Effect of argatroban on the activated partial thromboplastin time: a comparison of 21 commercial reagents.

Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis, 2005

Research

Argatroban in the management of heparin-induced thrombocytopenia.

Vascular health and risk management, 2010

Research

Evaluation of a standardized protocol using lepirudin or argatroban for heparin-induced thrombocytopenia.

Cardiovascular & hematological agents in medicinal chemistry, 2011

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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