Ultram ER is an opioid pain drug that treats moderately to moderately severe pain. Ultram ER is available in generic form as tramadol hydrochloric acid. It belongs to a drug class Narcotic analgesics, pain killers. Ultram ER releases within an hour after administering in two ways. First, it attaches to the ?-opioid receptor and secondly it blocks the reuptake of norepinephrine and serotonin.