(Portland, OR)  --  Tomorrow, you'll have a chance to safely dispose of unwanted, unneeded, or expired medications during National Prescription Drug Take-back Day.  The annual event, which is hosted by the Drug Enforcement Administration, is being held by police and sheriff's departments at various locations across the Portland-Vancouver metro area.  Officials say more than 24-hundred tons of combined medications were surrendered nationwide during the previous nine Take-back events.  More information, including locations of collection sites, is available online at dea.gov.