This will be a randomized, double-blind, controlled trial looking at all adult patients undergoing open abdominal urologic surgeries. After assessing the inclusion/exclusion criteria, the patients will be randomized into one of two groups:~Group 1: Sustained-release (long-acting) opioid on a regular basis for 2 days with immediate-release (short-acting) opioid available on an 'as required' basis~Group 2: Immediate-release (short-acting) opioid on an 'as required' basis only.~All patients will have a general anesthetic at the discretion of the anesthesiologist in the operating room and intravenous opioid will be administered in accordance with the anesthesiologists' discretion.~Pain score and analgesic consumption are the outcome measures.
The advantage of slow-release opioid allows for less fluctuation in drug (pain killer) levels in the blood and an extended period within the effective range for pain relief. The slow-release opioids have been preferred over the short-acting opioids because of the longer duration of action, which lessens the frequency and severity of end-of-dose pain.~Herein, the investigators propose the use of low dose slow-release opioid formulation offers better pain control in the first 48 hours post-operatively in open abdominal urologic surgeries.