This question was forwarded to me by my friend and colleague, Marisa Marques, MD, Director of the University of Alabama at Birmingham Hospital special coagulation laboratory and transfusion service:
“One of our pharmacists asked if there was a maximum dose for the heparin bolus or infusion rate for obese patients since our current recommendations are based on body weight. I haven’t been able to find a recommendation to cap dosing for these patients.”
Hi, Dr. Marques. Here are the recommended IV dosages, given by Garcia DA, Baglin, TP, Weitz JI, Samama MM. Parenteral anticoagulants: antithrombotic therapy and prevention of thrombosis, 9th ed: American College of Chest Physicians evidence-based clinical practice guidelines. Chest 2012; 141) :24S-43S:
Venous thromboembolic disease: 80 units/kg bolus, 18 units/kg/hour
Acute coronary syndrome: 60–70 units/kg bolus, maximum 5000 units, 12–15 units/kg/hour, max 1000 units/kg/h
If given with thrombolytic agents: 60 units/kg bolus, 12 units/kg/hour, maximum 1000 units/kg/hour
In the article the authors do not discuss a maximum dosage other than the limits given above. They do recommend regular monitoring to ensure that the dosage is within the therapeutic range. Likewise, they recommend monitoring subcutaneously administered low molecular weight heparin in patients who are either obese or underweight.
I’m interested to learn if any of the clinicians who regularly contribute to this site have had any experience with a maximum dose of unfractionated heparin in obese patients. Thanks for your question and check back here for further information.