File photo Actor Dennis Quaid image:35223:0::0

Heparin is used to keep IV catheters from clotting. The hospital said that a total of three patients received 10,000 units of heparin per millimeter instead of the prescribed 10 units/mm - or 1,000 times what was prescribed. Cedars-Sina is quoted by ABC News as saying:

This was a preventable error, involving a failure to follow our standard policies and procedures...Although it appears at this point that there was no harm to any patient, we take this situation very seriously.

Dr. Michael L. Langberg, the Chief Medical Officer of Cedars-Sinai Medical Center, issued a statement saying:

The error was identified by Cedars-Sinai staff, who immediately performed blood tests on the patients to measure blood clotting function. Four additional patients in the unit were tested as a precaution. The tests indicated that four of the seven patients had normal blood clotting function, and three had tests indicating prolonged blood clotting function. In one of the three patients, the clotting tests returned quickly to normal. The other two patients were given protamine sulfate, a drug that reverses the effects of heparin and helps restore blood clotting function to normal. Additional medical tests and clinical evaluation conducted on the two patients indicated no adverse effects from the higher concentration of heparin or from the temporary abnormal clotting function. Doctors continue to monitor the patients.

Last year, three premature babies at Methodist Hospital in Indianapolis, Indiana died from similar heparin overdoses. In that instance, a pharmacy technician stocked adult heparin for nurses instead of Hep-lock vials used in pediatrics. The Institute of Medicine estimates that 1.5 million patients annually receive incorrect medications. Some hospitals are now using bar codes to match the proper drugs with the correct patient, to prevent potentially dangerous mismatches.