Tizanidine for the management of acute postoperative pain after inguinal hernia repair: A placebo-controlled double-blind trial.

BACKGROUND

α2-Agonists are used postoperatively as a component of multimodal analgesia. Tizanidine is a centrally acting α2-agonist with muscle relaxant properties.

OBJECTIVE

The aim of this study was to compare the efficacy of tizanidine with placebo in terms of postoperative pain scores, analgesic consumption, return to daily activity and health-related quality of life.

DESIGN

A randomised double-blind study.

SETTING

Diskapi Yildirim Beyazit Training and Research Hospital.

INTERVENTIONS: After obtaining ethical approval and informed patient consent, 60 patients undergoing inguinal hernia repair under general anaesthesia were randomly allocated into one of the two groups. The patients in Group T received tizanidine 4 mg orally 1 h before surgery and twice daily during the first postoperative week. The patients in Group P received the same treatment with a placebo pill. Both the groups received a standard analgesic treatment regimen comprising intravenous dexketoprofen 25 mg prior to induction of anaesthesia, dexketoprofen 25 mg orally three times daily for 1 week and intravenous paracetamol 1 g at the end of surgery. Supplemental analgesia was provided with paracetamol if the visual numerical rating scale (NRS) was at least 4 cm.

MAIN OUTCOME MEASURES: Postoperative pain was assessed using the NRS. Total analgesic consumption was determined. Return to normal daily activity was evaluated using a five-point daily activity score after the first postoperative week, and health-related quality of life was evaluated using the short form-36 one month after surgery.

RESULTS

The patients in Group T had significantly lower NRS pain scores than those in Group P 6, 12 and 24 h postoperatively both at rest and during movement (P < 0.001), and on postoperative days 1, 2, 3 and 4. The analgesic consumption was also lower in patients who received tizanidine. Ten patients (33%) in Group T and 23 patients (77%) in Group P consumed supplemental paracetamol (P < 0.001) after discharge. The daily activity score was lower in Group T than in Group P (P < 0.001), and the short form-36 scores were significantly different in the pain dimension [74 (74 to 100) in Group T and 74 (31 to 80) in Group P, (P < 0.001)] and in the physical component summary score.

CONCLUSION

The addition of tizanidine to the postoperative pain therapy after herniorrhaphy decreased postoperative pain and analgesic consumption and improved return to normal activity and quality of life.

TRIAL REGISTRATION: ClinicalTrials.gov NCT02016443 (10 October 2013, Principal investigator D. Yazicioğlu).