What regimen does this page illustrate?

It illustrates one high-intensity VTE regimen: an 80 units/kg IV bolus (maximum 10,000 units) and an initial infusion of 18 units/kg/hr (maximum 1,800 units/hr). This is not universal; always use the indication-specific institutional order set.

Why is there a maximum cap on the bolus and infusion?

Dose caps are protocol-specific safeguards. This example uses a 10,000-unit bolus cap and 1,800-units/hr maximum initial rate; other validated protocols may use different caps or no cap. Never transfer these limits to another indication or institution.

What body weight should be used — actual or ideal?

Standard UFH weight-based protocols use actual body weight (ABW). Some institutions use adjusted body weight for morbidly obese patients (BMI ≥ 40), but this varies. Confirm with your institution's heparin policy.

What bag concentration does this tool assume?

The calculator defaults to the standard preparation of 25,000 units in 250 mL (100 units/mL), but you can also select 50 units/mL (25,000 units in 500 mL) or 200 units/mL (25,000 units in 125 mL) directly from the bag concentration dropdown.

Is this calculator a replacement for clinical judgment?

No. This tool is for educational and reference purposes only. Heparin dosing requires aPTT monitoring, clinical assessment of bleeding risk, renal function, platelet counts (to watch for HIT), and adherence to validated institutional protocols. Always verify orders with a licensed pharmacist or physician.

When should heparin NOT be used?

Absolute contraindications include active major bleeding, heparin-induced thrombocytopenia (HIT), and severe thrombocytopenia. Relative contraindications include recent surgery, intracranial hemorrhage, and severe liver disease. Clinical evaluation is mandatory before initiating anticoagulation.

Heparin Dosing Calculator

Enter patient weight to illustrate a high-intensity VTE UFH regimen: 80 units/kg bolus (max 10,000) and 18 units/kg/hr infusion (max 1,800 units/hr).

Patient Weight

Actual Body Weight (kg)

Standard protocols use actual body weight.

Bag Concentration (units/mL)

Protocol Reference

Bolus 80 units/kg

Bolus cap 10,000 units max

Initial infusion 18 units/kg/hr

Infusion cap 1,800 units/hr max (example protocol)

For educational purposes only — not a substitute for clinical judgment. Heparin is a high-alert medication. All doses must be verified by a licensed pharmacist or physician and managed with aPTT monitoring per an institutional protocol.

Enter patient weight and click Calculate Dose

IV Bolus Dose

Calculated (80 units/kg)

—

units

Dose to give

—

units IV push

Initial Continuous Infusion

Rate (units/hr)

—

units/hr

Pump rate

—

mL/hr

Calculation Summary

Patient weight —

Bolus (80 units/kg) —

Infusion (18 units/kg/hr) —

Bag concentration used —

Clinical Next Steps

1. Obtain baseline aPTT, PT/INR, CBC, and platelet count before initiating therapy.
2. Recheck aPTT 6 hours after bolus or any rate change.
3. Adjust infusion rate per your institution's validated aPTT-based heparin nomogram.
4. Monitor platelet count every 2–3 days to detect heparin-induced thrombocytopenia (HIT).
5. Verify all doses with a licensed pharmacist or physician before administration.

Summary