Comparison of the Efficacy of Adding Clonidine, Chlorpromazine, Promethazine, and Midazolam to Morphine Pumps in Postoperative Pain Control of Addicted Patients

Background: Addicted patients present difficulties for pain management because they have another problem besides their pain. Adding adjuvants to opioid pumps to inten- sify quality, control other problems, lengthen analgesia, and reduce side effects has been considered in the field. Objectives: The objective of this study was to evaluate the analgesic effects of adding clonidine, promethazine, chlorpromazine, and midazolam to morphine in patient- controlled intravenous analgesia (PCIA) in orthopedic patients with addiction prob- lems. Patients and Methods: 90 patients with histories of substance abuse were enrolled in this randomized controlled trial. Patients were randomly divided into three groups. The first group received 20 mg of morphine sulfate plus 50 mg of chlorpromazine plus 50 mg of promethazine plus 10 mg of midazolam (M20P). The second group re- ceived the first group’s regimen plus 150 micrograms of clonidine (M20PC). The third group received 40 mg of morphine sulfate (M40). A pump with a flow rate of 5 mL/h was chosen. Patients were evaluated every 12 hours, and visual analogue scale (VAS), verbal rating scale (VRS), extra opioid usage, nausea and vomiting (N&V), and sedation scores were recorded. Results: Patients’ nausea and vomiting and sedation scores were not statistically differ- ent between the three groups. Mean VAS and VRS scores were found to be statistically lower in the M20PC group than in the other groups. Extra opioid usage between the three groups was statistically lower in the M20PC group than in the other groups. The percentage of patients satisfaction was significantly higher in the M20PC group than in the other two groups. Conclusions: This study showed that, compared to simply increasing the dose of mor- phine, adding chlorpromazine, promethazine, midazolam, and clinidine to morphine significantly controlled pain scores and increased treatment satisfaction in addicted patients without notable side effects.