Methodist Hospital in Indianapolis plans to increase medication safeguards after a drug stocked in the wrong cabinet led to the deaths of three premature babies, the Associated Press reported.

On September 16, nurses went to a drug cabinet in the newborn intensive care unit to get blood thinner for several premature babies, but the cabinet had been mistakenly stocked withvials containing a dose 1,000 times higher than the babies were supposed to receive. The nurses didn't notice that a pharmacy technician had stocked the cabinet with heparin instead of hep-lock, nor did they notice that the heparin label was a different color than hep-lock (dark blue vs. baby blue). In addition to the three infant deaths, three other babies suffered overdoses but survived.

Hep-lock contains a lesser dosage of heparin that is routinely used to keep intravenous lines open in premature babies. It arrives at the hospital in premeasured vials and is placed in a computerized drug cabinet by pharmacy technicians.

Nurses must enter their employee code and the patient's code into the cabinet's computer to open it. After the drawer opens, nurses select the prescribed meds and enter the amount withdrawn. The system locks afterward to prevent multiple withdrawals for the same patient, but there is no way to prevent nurses from taking the wrong drug.

Hospital officials said the pharmacy tech loaded the cabinet with heparin (10,000 units per millileter) instead of hep-lock (10 units per millileter). Two of the babies died within hours of receiving the heparin, and a third died on September 19. No autopsies were performed, but officials said the cause of death was likely internal bleeding.

Methodist officials adopted new safety measures to prevent future errors, including procedures requiring a minimum of two nurses to verify any dose of blood thinner in the newborn and pediatric critical-care units. No disciplinary action will be taken against those involved in the error.