How do you calculate heparin units?

Heparin units are calculated based on the anticoagulant activity of the heparin preparation, which is typically expressed in International Units (IU). To determine the units, you need to reference the manufacturer's specifications, as the potency can vary between products. The calculation often involves measuring the activated partial thromboplastin time (aPTT) or anti-factor Xa activity in the patient's blood and comparing it to standard curves. Dosing adjustments may be made based on these laboratory results to achieve the desired therapeutic effect.