OBJECTIVES: We aimed to examine the cognitive effects of mitragynine substitution in morphine-withdrawn rats. Furthermore, we asked whether neuronal addiction markers like the brain-derived neurotrophic factor (BDNF) and Ca2+/calmodulin-dependent kinase II alpha (αCaMKII) might mediate the observed effects.
METHODS: Male Sprague-Dawley rats were given morphine at escalating doses before treatment was discontinued to induce a spontaneous morphine withdrawal. Then, vehicle or mitragynine (5 mg/kg, 15 mg/kg, or 30 mg/kg) substitution was given for 3 days. A vehicle-treated group was used as a control. Withdrawal signs were scored after 24 h, 48 h, and 72 h, while novel object recognition (NOR) and attentional set-shifting (ASST) were tested during the substitution period.
RESULTS: Discontinuation of morphine significantly induced morphine withdrawal signs and cognitive deficit in the ASST. The substitution with mitragynine was able to alleviate the withdrawal signs. Mitragynine did not affect the recognition memory in the NOR but significantly improved the reversal learning deficit in the morphine-withdrawn rats.
CONCLUSIONS: These data support the idea that mitragynine could be used as safe medication therapy to treat opiate addiction with beneficial effects on cognitive deficits.
Methods: Based on the morphine withdrawal model, rats were morphine treated with increasing doses from 10 to 50 mg/kg twice daily over a period of 6 days. The treatment was discontinued on day 7 in order to induce a spontaneous morphine abstinence. The withdrawal signs were measured daily after 24 h of the last morphine administration over a period of 28 abstinence days. In rats that developed withdrawal signs, a drug replacement treatment was given using mitragynine, methadone, or buprenorphine and the global withdrawal score was evaluated.
Results: The morphine withdrawal model induced profound withdrawal signs for 16 days. Mitragynine (5-30 mg/kg; i.p.) was able to attenuate acute withdrawal signs in morphine dependent rats. On the other hand, smaller doses of methadone (0.5-2 mg/kg; i.p.) and buprenorphine (0.4-1.6 mg/kg; i.p.) were necessary to mitigate these effects.
Conclusions: These data suggest that mitragynine may be a potential drug candidate for opiate withdrawal treatment.
METHODS: Ninety-seven patients with adolescent idiopathic scoliosis (AIS) who underwent posterior spinal fusion surgery at a single tertiary institution from March 2019 until June 2020 were enrolled in this retrospective study. Anesthesia was maintained using a target-controlled infusion of remifentanil combined with volatile anesthetic desflurane in 92 patients, while five patients received it as part of total intravenous anesthesia. Intravenous ketamine, paracetamol, and fentanyl were administered as multimodal analgesia. All patients received patient-controlled analgesia (PCA) morphine postoperatively. Pain scores at rest and on movement, assessed using the numerical rating scale, and the cumulative PCA morphine consumption were collected at a six-hourly interval for up to 48 h. According to the median intraoperative remifentanil dose usage of 0.215 µg/kg/min, patients were divided into two groups: low dose and high dose group.
RESULTS: There were no significant differences in the pain score and cumulative PCA morphine consumption between the low and high dose remifentanil group. The mean duration of remifentanil infusion was 134.9 ± 22.0 and 123.4 ± 23.7 min, respectively.
CONCLUSION: Intraoperative use of remifentanil as an adjuvant in AIS patients undergoing posterior spinal fusion surgery was not associated with postoperative hyperalgesia.
METHODS: This prospective, double-blind, randomized study enrolled 60 female patients scheduled for unilateral mastectomy and axillary clearance. The patients received either a superficial serratus plane block or deep serratus plane block. Dermatomal spread was recorded 30 minutes after block administration. Postoperatively, pain visual analog scale (VAS) scores were documented at recovery (time 0), at 30 minutes; and in the ward hourly for 4 hours, and 4-hourly until 24 hours postoperatively. The time to first analgesic rescue and cumulative morphine consumption using patient-controlled analgesia morphine (PCAM) were recorded.
RESULTS: The results showed lower VAS scores at rest (at 1, 2, 3, and 4 hours postoperatively), and during movement (at 1, 2, 3, 4, 8, and 24 hours postoperatively) in the superficial serratus plane block group, P < .005. Similarly, cumulative morphine usage was lower in the superficial serratus plane group, P < .005. The time to the first rescue analgesic was also significantly longer in the superficial group, P < .001. More patients in the superficial serratus plane group achieved greater dermatomal spread at T2 and T7 than those in the deep group.
CONCLUSIONS: Superficial serratus plane block provides better analgesic efficacy than deep serratus plane block in mastectomy and axillary clearance.