Covidien Ltd. has recalled thousands of mislabeled syringes that could cause people with diabetes to take by mistake a dangerous overdose of insulin, federal health officials announced.

The healthcare products company distributed 4,710 boxes in the recalled lot with 471,000 syringes, all put on the market by Wal-Mart Stores Inc. at the Wal-Mart Super centers or Sam’s Club stores. The lot was shipped from August 1st, 2008 through October 8th, 2008. Overall, an estimated 500,000 single use, disposable, hypodermic, insulin syringes have been recalled.

The Food and Drug Administration said the recalled ReliOn syringes might be mislabeled. An insulin overdose of as much as 2.5 times the intended dose administered to diabetes patients could lead to low blood sugar levels, serious health effects and even death. Already one such adverse event has been reported, the FDA said in a press release.

While being packed, a large number of syringes labeled for use with U-40 insulin were accidentally mixed with syringes labeled for use with U-100 insulin. In order to inform and warn people about the possible mislabeling and overdose risk, announcements have been posted on the Wal-Mart website, as well as in Wal-Mart stores and Sam’s Clubs. Besides, Covidien Ltd. has sent out notification letters addressed to more than 16,500 customers.

“Product safety and quality continue to be our number one priority. We apologize for any confusion or inconvenience this issue may cause you,” said ReliOn on its Web site recall page. “We value your continued support.”