The effects of volume and baricity of spinal bupivacaine on block onset, height, duration when it’s associated with fentanyl and hyperbaric lignocaine are very effective but has many adverse effects. We conducted this review among published studies found in electronic medical databases such as; PubMed, Embase, up to the beginning of 2022. According to studies, the addition of clonidine to intrathecal bupivacaine provides longer-lasting postoperative analgesia than fentanyl, albeit with a greater sedative effect. Clonidine prolongs postoperative analgesia more than fentanyl, hence fentanyl is suggested when sedation is undesirable while clonidine is advised when sedation is acceptable.