Physicians are overriding a vast majority of safety alerts about potentially bad drug interactions, a new three-state study finds. Doctors, probably more annoyed than enlightened, instead are relying on their own judgment rather than that of commercial services, researchers said in last week’s edition of the Archives of Internal Medicine.

Investigators examined prescribing practices of nearly 3,000 doctors in Massachusetts, New Jersey and Pennsylvania who submitted 3.5 million prescriptions over the first nine months of 2006. Researchers said doctors overrode more than 90% of the nearly 235,000 drug interaction alerts and 77% of drug allergy cautions.

“The sheer volume of alerts generated by electronic prescribing systems stands to limit the safety benefits,” said lead study author Dr. Thomas Isaac, of the Dana-Farber Cancer Institute and Beth Israel Deaconess Medical Center in Boston. “Too many alerts are generated for unlikely events, which could lead to alert fatigue. Better decision support programs will generate more pertinent alerts, making electronic prescribing more effective and safer.”

The researchers said medication safety alerts could be improved by reclassifying frequently overridden alerts, giving doctors a way to suppress certain alerts for medications already cleared, and customizing alerts based on a doctor’s specialty.