Administrators said Sebastian Ferrara's parents brought the child to the University of Florida Pediatrics Clinic and the Shands Medical Plaza for a routine growth hormone stimulation test involving the amino acid arginine.

"The nurse did not check the dosage against the label," CEO for UF's Faculty Group Practice Jane Schumaker explained. "She believed the dose to be administered was the dose had been dispensed."

Even after Sebastian's mother questioned the dosage of arginine, the healthy boy still received 60 grams of the amino acid; his prescription was for 5.75 grams.

"Our investigation to date has identified a series of errors that collectively caused the tragic outcome," Donald Novak, medical director of the UF Pediatric Clinics, said.

During the three hour test, Sebastian complained of a headache, leading to his father calling for a doctor, who check the boy but did not stop the procedure. This is the second time this year a mistake like this has been made.

"We found another child who had gotten an excessive dose of arginine," Novak said. "The other child received a smaller dose and was somewhat larger."

Administrators said the overdose was not recognized at the time, but the child's parents have been notified and there have been no long term effects. The amount Sebastian received and his small size, however, led to cerebral edema - swelling of the brain - and his death two days later at the pediatric intensive care unit at Shands at UF. A nurse and pharmacist are on administrative leave.

"We have to look at the people for sure, but we absolutely have to look at the other systems," Director of Pharmacy Services Alan Knudsen said.

Medical examiners are waiting on toxicology reports, but hospital administrators said arginine was the "definitive cause" of Sebastian's death and steps are being taken to ensure this does not happen again.

"We are looking at how the arginine prescription was processed at the pharmacy and how it was administered in the clinic," Novak said. By Ted Latiak, WCJB TV20 News.