BOSTON (AP) -- Fall River Mayor William A. Flanagan on Monday urged President Barack Obama to intervene in the U.S. Food and Drug Administration’s approval of the new painkiller Zohydro.

In a letter issued Monday, Flanagan requested the president to ask FDA Commissioner Margaret Hamburg to either order San Diego-based drug maker Zogenix to reformulate the drug or mandate its removal from the market entirely. Flanagan also issued a letter to Zogenix CEO Roger L. Hawley.

Gov. Deval Patrick had tried to ban Zohydro in Massachusetts, but a federal judge this month struck down his executive order as unconstitutional. Patrick has since issued stricter requirements for doctors prescribing the drug.

The company, which has said it is working on an abuse-deterrent form of the drug, maintains that Zohydro is no more potent, on a per-milligram basis, than Vicodin or other hydrocodone pills currently on the market.

Some health authorities warn addicts can crush the capsules, thwarting their slow-release properties, and then snort or inject the drug for an immediate and extremely powerful high that can prove lethal.

They also say the drug is available in dosages of hydrocodone that are five times greater than the highest dose in other hydrocodone-containing products. Zohydro is available in 50-milligram doses of hydrocodone. Other products contain doses of 2.5 to 10 milligrams of hydrocodone.

Massachusetts isn’t the only state raising concerns about the drug: Vermont has also issued tougher regulations for prescribing Zohydro. Bills have also been introduced in Congress to ban the drug. And more than two dozen state attorneys general have asked the FDA to reconsider its approval of Zohydro.