LOS ANGELES (AP) ¿ Dennis Quaid and his wife sued the makers of heparin this week after their newborn twins were inadvertently given massive doses of the blood thinner at a hospital.

The product liability lawsuit, filed in Chicago, seeks more than $50,000 in damages. It claims that Baxter Healthcare Corp., based in Deerfield, Illinois, was negligent in packaging different doses of the product in similar vials with blue backgrounds. The lawsuit also says the company should have recalled the large-dosage vials after overdoses killed three children at an Indianapolis hospital last year.

The lawsuit was first reported by CelebTV.com, which obtained the court documents.

The company had not been served with the lawsuit and could not comment specifically on it, spokeswoman Deborah Spak said.

However, "this is not a product issue. The issue here is about improper use of a product," she said.

"While we strive to clearly differentiate our products and dosages, no amount of differentiation will replace the value of clinicians carefully reviewing and reading a drug name and dose before dispensing and administering it," she added.

This fall, the company changed its heparin packaging by adding a red caution label that must be torn off before the vial can be opened.

The Quaids' children, Thomas Boone and Zoe Grace, and a third patient were at Cedars-Sinai Medical Center on November 18 when they were mistakenly given vials of heparin that were 1,000 times stronger than the usual dosage.

The twins were home Tuesday and "appear to be doing well," said Susan E. Loggans, the Chicago attorney who filed the lawsuit.