Des Moines hospitals are putting up a stark warning to anyone tempted to scam emergency-room doctors into prescribing large amounts of painkilling pills: Don’t bother trying. Mercy Medical Center put up signs last year warning that its ER doctors would prescribe pain medication only for emergency medical conditions. Mercy will soon put up the same signs in its urgent-care clinics, and its main rival, Iowa Health-Des Moines, is poised to follow suit. The hospitals' signs and stricter policies are a reaction to increasing abuse of prescription narcotics, such as Oxycontin, hydrocodone and methadone, and increasing deaths from overdoses.