A Warning for Diabetics with Heart Failure
A Warning for Diabetics with Heart Failure
Doctors are still prescribing drugs known to be dangerous to these patients

By Richard N. Fogoros, M.D.
About.com Guide to Heart Disease since 2000

A new study appearing on July 2 in the Journal of the American Medical Association shows that many doctors continue to prescribe potentially dangerous diabetes drugs for patients who have both diabetes and heart failure. The drugs, metformin (Glucophage) and the thiazolidinediones (such as Avandia and Actos), according to FDA warnings, should not be used in diabetics who have significant heart failure. Yet, this new study shows, nearly 25% of patients with heart failure and diabetes are receiving one or more of these drugs, and furthermore this percentage has significantly increased over the past few years.

In the case of metformin, the FDA-approved labeling actually places a black box (a means of emphasis) around the warning stating that the drug can produce potentially fatal lactic acidosis in patients with heart failure. For the thiazolidinediones, the risk is that the drugs can worsen heart failure in patients who have significant degrees of heart failure.

The study does not identify why patients are being given potentially dangerous drugs – are doctors ignorant of the risks, or have they taken the risks into account and decided that the benefits of treatment outweigh the risks?

This is an important question. When the FDA (and drug companies) identify a toxic effect of a drug, they tend to err on the side of conservatism. By warning doctors not to use the drugs under various circumstances, they shed their own risk of legal liability. The doctors, on the other hand, are faced with actually having to administer medical care to sick patients – and not uncommonly, the “best” option for a given patient involves a treatment that carries some substantial risk. Completely ruling out that “best” option, just to spare themselves the risk of lawsuit, often does not constitute optimal medical care. Before prescribing such treatment, however, the doctor is obligated to discuss the potential risks and benefits in detail with the patient, and make sure the patient is willing to accept those risks.

Then there is the more disturbing possibility that many of these doctors are simply ignorant of the risks, and continue to prescribe these drugs in blissful oblivion.

What should you do if you have diabetes and heart failure, and are taking one of these drugs?

You should quickly figure out whether your doctor has prescribed the drug after carefully considering the risks and benefits, or whether he/she has acted out of ignorance. If the former, make sure you have discussed this decision with your doctor, and that you are fully in agreement with his/her rationale for continuing to use the drug. If the latter, you might want to take that into account when deciding how many other life-and-death decisions you want to entrust to this individual.