Circulation 60,475 • Volume 13, No. 1 • Spring 1998

Summary of Feb. 5, 1998, Meeting of the Anesthetic and Life Support Drugs Advisory Committee of ASA

Terese T. Horlocker, M.D.

Topic: Class Labeling Revisions for the Low Molecular Weight Heparin (LMWH) and Heparinoids

The committee discussed three questions relating to the labeling of low molecular weight heparins and heparinoids, specifically:

1. Are the revisions sufficient to convey the risks associated with these products when spinal/epidural anesthesia or spinal puncture is used?

The committee generally felt that the label revisions were adequate, considering the small amount of data available. The committee emphasized the need for increasing the awareness of all health care practitioners to the risks, and recommended strong educational and surveillance programs.

If insufficient, what additional actions should be initiated? Consider the following:

a. Further revisions to the package insert including the addition of information on how to use anticoagulants for thromboprophylaxis in the setting of neuraxial anesthesia or spinal puncture;

b. Restricted use of LMWHs and heparinoids to “special circumstances” in patients administered spinal/epidural anesthesia;

c. Contraindication of the use of LMWHs and heparinoids in patients with spinal/epidural catheters.

The committee felt that the European Guidelines for the perioperative use of the low molecular weight heparins should be considered further, but that the current amount of data is too sparse to tightly link the adverse events to the timing of the insertion and removal of catheters. There is concern among the committee that if warnings are too strong, the use of regional anesthesia will be limited unnecessarily. They felt that the physicians should be given sufficient information to make an educated decision about the relative risks of the different types of anesthesia, and the balance of the risks of perioperative thromboembolic complications and spinal or epidural hematomas.

2. If further labeling revisions are proposed, what pharmacological or clinical data would be necessary to support the proposed changes?

The committee recommended considering the inclusion of statements regarding the length of time that these remain pharmacologically active, and a statement indicating that, to date, most of the adverse events have occurred in elderly women.

3. Should the class labeling be extended to all approved anticoagulants (e.g., heparin and warfarin products)?

Total votes = 8

Yes – 1 No – 5

Two committee members felt that any class labeling should be extended to heparin, but not to warfarin.

Submitted by Terese T. Horlocker, M.D., Guest Chair Anesthetic and Life Support Drugs Advisory Committee