Wyeth-Ayerst Pharmaceuticals recently took steps to warn of potential dangers of using the heart medication Cordarone (generic name: amiodarone) in pediatric patients. The Food and Drug Administration (FDA) last week notified physicians that an official change in labeling has taken place to reflect these concerns. This medication was never approved to treat pediatric patients and the original labeling does indicate this fact. Despite this, off-label use in pediatric patients is quite common. Off-label use of medications by physicians is legal as long as a medication is approved for general use by the FDA. Such practice is relatively commonplace for many other types of medications.

Amiodarone is indicated in the treatment of a heart rhythm disturbance known as ventricular arrhythmias. Specifically, it is intended to be used for disturbances of this kind that are life-threatening, repetitive and hard to treat with other medications. The medication does have a number of potential side-effects and the labeling clearly states that no studies in pediatric patients have been done.

The company has identified two possible risks that caused it to release its warning. Both of these risks occur when the intravenous form of the medication is used - not the tablet form that patients might take at home.

The first problem is that the medication may cause a syndrome known as "gasping syndrome" in neonates. This can be a potentially fatal side effect. The second problem involves the fact that the medication reacts with the plastic tubing used in intravenous lines. When it is infused through these lines, the company states that it can "leach out plasticizers" and these chemicals have been shown in animal studies to have potentially harmful effects on the male reproductive system during development.

Anesthesiologists, in the setting of both the operating room and the intensive care unit, are among the group of physicians that use amiodarone frequently. It is important, therefore, for those caring for pediatric patients to be aware of these possible problems and take heed of the warnings from the company and the FDA.