In this study, time to first analgesic request was significantly prolonged in fentanyl group compared with placebo group. This result corroborates the findings of Techanivate et al.,[2] in which time to first request for post‐operative analgesic was significantly prolonged when comparing fentanyl group with placebo group (11.0 h vs. 4.7 h respectively, P < 0.05).