WASHINGTON (AP) — Federal regulators are warning doctors in an online posting that one lot of injectable painkillers from Hospira may contain too much of the drug.

Hospira recalled one lot of its Hydromorphone Hydrochloride Injection after finding a vial that contained more than the 1 milligram listed on the label. Hydromorphone is derived from morphine and is used to treat severe pain conditions.

The recalled products come from lot number 07547LL and have an expiration date of July 1, 2013. They were distributed to wholesalers in more than two dozen states last September and October.

The drug is sold in prefilled glass vials for use with Lake Forest, Ill.-based Hospira’s Carpuject syringe injector.

The FDA said in Monday’s posting that anyone with the drug should stop using it immediately and call 1-888-912-7093.