A nationwide investigation of a possible protamine drug-product defect

To follow-up a report submitted to FDA Spontaneous Reporting System, we investigated the hypothesis that there was not a striking increase in unexpected deaths within four hours after elective coronary artery bypass surgery associated with protamine sulfate use.

Surveys were mailed to clinical pharmacists at 521 hospitals participating in the Drug Surveillance Network. Questionnaires were to be completed with the assistance of cardiac surgeons and anesthesiologists. Hospitals responding with a suspected problem with protamine were contacted via telephone.

Surveys were received from clinical pharmacists at 380 hospitals (73 percent response rate) and 29 hospitals reported the occurrence of potential problems associated with protamine during coronary artery bypass graft surgery. Telephone interviews of the positive responders yielded six cases of possible myocardial decomposition potentially associated with protamine. There was no association with a specific distributor, however, and none of the hospitals reported a dramatic increase in serious adverse events around the time of index cases.

There was no evidence of a widespread public health problem with protamine and a product recall was not necessary. The high response rate and the ability to follow-up with telephone interviews suggests that the Drug Surveillance Network is an effective mechanism for investigating possible outbreaks of serious adverse events in the hospital setting.