Two of the patients needed a drug that reverses the effects of heparin, the hospital said at the time.

The hospital issued an apology to the patients' families, and said it would take "all steps" to prevent a recurrence.

The heparin was "unreasonably dangerous" as it was packaged and sold because both the small and large dosage vials had labels with blue backgrounds when the vials "should have been completely distinguishable (by) size and shape," the lawsuit argued.

A similar dosage error killed three premature infants at an Indianapolis hospital last year. Three others survived overdoses.

In February, Baxter Healthcare Corp. sent a letter warning health care workers to carefully read labels on the heparin packages to avoid a mix-up.

But the lawsuit by Quaid and his wife, Kimberly, argues that the company didn't do enough.

The company failed to recall the large-dosage vials after the infant deaths and repackage the drug, the lawsuit contends.

It said the manufacturer also should have issued an "urgent" warning to health care providers that required them to educate nurses and others about the problems and implement safety procedures.