Pregabalin and Dexmedetomidine Combined for Pain After Total Knee Arthroplasty or Total Hip Arthroplasty Performed Under Spinal Anesthesia

: Pregabalin and dexmedetomidine have been introduced to manage postoperative pain. This study evaluated the effect of the 2 drugs combined on pain in patients undergoing total knee or hip arthroplasty. A total of 124 patients undergoing total knee or hip arthroplasty under spinal anesthesia were randomly assigned to either group C (n=31, placebo), group P (n=33, pregabalin), group PD (n=29, pregabalin and dexmedetomidine), or group D (n=31, dexmedetomidine). One hour before spinal anesthesia, patients received 150 mg of pregabalin or placebo orally, and a bolus dose of 0.5 µg/ kg of intravenous dexmedetomidine was given over 10 minutes before induction of spinal anesthesia. This was followed by a continuous infusion of 0.5 µg/kg/h or the same calculated volume of normal saline until completion of the surgery. Clinically relevant pain for 24 hours postoperatively, including time to first analgesic request, visual analog scale score, ketorolac dose, and volume of patient-controlled analgesia consumed, was recorded. Group C had significantly longer time to first analgesic request, higher visual analog scale scores at rest and on movement, higher ketorolac dose, and higher volume of patient-controlled analgesia for the first 24 hours postoperatively compared with the other groups. Although group PD and group D had less clinically relevant pain than group P, group PD and group D were not significantly different. Dexmedetomidine was more effective than pregabalin for clinically relevant pain. Pregabalin and dexmedetomidine combined had no synergic effect compared with dexmedetomidine alone. [Orthopedics. 2018; 41(6):365-370.].