What is the indication for Heparin (unfractionated heparin) 3000 units administered 8 hourly?

Indications for Heparin 3000 Units 8 Hourly

Heparin 3000 units administered subcutaneously every 8 hours is primarily indicated for venous thromboembolism (VTE) prophylaxis in low-weight patients or those with moderate bleeding risk. 1

Primary Indications

• Prophylaxis of deep vein thrombosis (DVT) and pulmonary embolism (PE) in hospitalized patients weighing less than 50 kg 1, 2
• VTE prophylaxis in patients with increased bleeding risk where standard 5000 unit dosing may be inappropriate 3
• Thromboprophylaxis in patients with renal impairment where low molecular weight heparins (LMWHs) are contraindicated 3, 2

Dosing Considerations

Weight-Based Considerations

• Standard prophylactic dosing of unfractionated heparin (UFH) is typically 5000 units every 8-12 hours 3, 2
• The 3000 unit dose represents a reduced dose for patients with lower body weight or increased bleeding risk 1
• For patients weighing >100 kg, the 3000 unit dose would be inadequate as higher doses (5000 units) are recommended 1, 2

Frequency Considerations

• The 8-hour frequency (three times daily) is preferred over 12-hour dosing for more effective VTE prophylaxis 4, 5
• Three times daily dosing provides more consistent anticoagulant effect compared to twice daily dosing 3
• Meta-analyses show that three times daily dosing of UFH is more effective at preventing clinically relevant VTE events than twice daily dosing 5

Advantages of This Regimen

• Does not require routine monitoring of aPTT for prophylactic dosing 1
• Primarily metabolized by the liver, making it suitable for patients with renal impairment 3, 2
• Can be used when LMWHs are contraindicated (e.g., in patients with history of heparin-induced thrombocytopenia) 3

Clinical Context

• Used primarily in inpatient settings for medical and surgical patients at risk for VTE 3
• Duration for medical patients is typically until hospital discharge or full ambulation 2
• For surgical patients, prophylaxis should be continued for at least 7-10 days 3, 2

Potential Pitfalls

• The 3000 unit dose may be subtherapeutic for standard-weight or obese patients, who typically require 5000 units 1, 2
• Inadequate prophylaxis may occur if the reduced dose is used inappropriately in patients who should receive standard dosing 1
• Three times daily dosing carries a slightly higher bleeding risk compared to twice daily dosing, though this is more significant with the 5000 unit dose 5, 6

Alternative Prophylactic Options

• For standard-weight patients: UFH 5000 units subcutaneously every 8 hours 3
• For patients with normal renal function: LMWHs such as enoxaparin 40 mg daily or dalteparin 5000 units daily 3, 2
• For patients with cancer: LMWH is generally preferred over UFH unless contraindicated 3