One hundred nineteen patients undergoing foot or ankle surgery were randomized to receive intravenous dexamethasone combined with dexmedetomidine (n=39), dexamethasone alone (n=40), or placebo (n=40). The primary outcome was the duration of analgesia, measured as the time from nerve block to first pain sensation. Secondary outcomes included the duration of motor block, opioid consumption, pain scores, and sleep quality over 72 hours. The median duration of analgesia was longest in the dexamethasone-dexmedetomidine group (1,572 minutes) compared to dexamethasone alone (1,400 minutes) and placebo (870 minutes). However, there was no significant difference in duration between the combined therapy and dexamethasone alone. Combined therapy reduced opioid consumption and pain scores within 24 hours but showed no additional benefit beyond that timeframe. Overall, dexamethasone, with or without dexmedetomidine, significantly extended analgesia and reduced early opioid use compared to placebo, suggesting its clinical utility in prolonging nerve block effects.