Doctor Prescribes Dangerous Dose of Coumadin

Case Overview

This case takes place in Maryland and involves a male patient who had a prior history of lung disease related to blood clots which was worsening. The doctor’s plan was to have the patient take 5 mg of Coumadin a day, however the instructions that were given to the pharmacist had the patient taking twice that amount. Over the course of a few weeks, the patient continued to take the Coumadin as he had been instructed. At some point, the patient showed symptoms of internal bleeding and went back to see the doctor who sent him immediately to the ER. He was hospitalized for over two weeks. It is alleged that the doctor over-prescribed Coumadin and failed to monitor him and instruct the patient to have his INR tested daily until he reached a therapeutic level.

Questions to the Pediatrics expert and their responses

What kind of checks/protocols should be taken before prescribing Coumadin to a patient?

Not all patients meet indications for the initiation of anticoagulation and a proportion of those meeting these indications do not qualify secondary to a high bleeding risk or other factors. The risk of stroke should be weighed against the risk of bleeding which is more difficult to quantify. There are several scoring systems available to assess the risk of bleeding (eg HAS-BLED score) but these are less commonly used. A patient's likelihood of compliance with drug administration and monitoring should also be considered as should their consumption of foods or medications known to interact with Coumadin metabolism. If a patient is deemed to be a Coumadin candidate (ie meets indications and does not exhibit evidence of contraindications) Coumadin may be started. Ideally, the patient should be educated regarding the risks of bleeding with Coumadin, the need for compliance with drug administration and monitoring, and the potential for drug or dietary interactions.

How often should INR be tested until a patient reaches a therapeutic level?

There are multiple approaches to the frequency of INR monitoring during the initiation phase of Coumadin therapy. I will typically test the INR 2 to 4 days after initiation of Coumadin and every 3 to 5 days thereafter until the INR level has been therapeutic for at least 2 consecutive checks.

Can Coumadin overdose contribute to a patient's permanent loss of pulmonary function and/or death?

Coumadin overdose could contribute to loss of pulmonary function and death through several mechanisms. A few of these mechanisms of death include but are not limited to death through exsanguination, brain injury, cardiac tamponade, or asphyxiation. It is likely that the failure to monitor the patient here was a lapse in the standard of care.

About the expert

This Board Certified Cardiologist completed his Fellowship training in General Cardiology and Cardiac Electrophysiology from Johns Hopkins Hospital. He is a member of the American College of Cardiology and has authored more than 25 publications in the field of cardiology. Currently, he is the Program Director of Electrophysiology and an Assistant Professor of Medicine at a Maryland-based university medical center, and is the Chief Medical Officer at a private medical company.