4218T/C polymorphism associations with post-cesarean patient-controlled epidural fentanyl consumption and pain perception

Pharmacogenetics of opioid medications for relief of labor pain and post-cesarean pain: a systematic review and meta-analysis

OBJECTIVE

Several studies have attempted to identify genetic determinants of clinical response to opioids administered during labor or after cesarean section. However, their results were often contrasting. A systematic review and meta-analysis was conducted to quantitatively assess the association between gene polymorphisms and clinical outcomes of opioid administration in the treatment of labor pain and post-cesarean pain.

METHODS

A comprehensive search was performed up to December 2023 using PubMed, Web of Knowledge, Cochrane Library, and OpenGrey databases. The clinical endpoints of interest were pain score after opioid treatment, total opioid consumption, patient's analgesic satisfaction, and incidence of opioid side effects. Random-effects meta-analyses were conducted when data were available in at least three studies.

RESULTS

Twenty-six studies enrolling 7765 patients were included in the systematic review. Overall, a total of 12 candidate polymorphic genes (OPRM1, COMT, CYP2D6, CYP3A4, ABCB1, ABCC3, UGT2B7, CGRP, OPRK1, OPRD1, KCNJ6, KCNJ9) were considered by the included studies, among which the most investigated variant was OPRM1 rs1799971. Overall pooled results indicated that individuals carrying the G allele of OPRM1 rs1799971 required higher opioid doses for pain management in comparison to rs1799971 AA subjects (standardized mean difference: 0.26; 95% CI: 0.09-0.44; P = 0.003). Such an association was confirmed in the subgroups of patients with labor pain and post-cesarean pain.

CONCLUSION

The present meta-analysis provides strong evidence of an association between OPRM1 rs1799971 and opioid dose requirement for relief of labor pain or post-cesarean pain. However, given the insufficient evidence for other polymorphic gene variants, large studies are still needed to investigate the impact of genetic variability on the efficacy and safety of opioid medications for relief of labor pain and post-cesarean pain (INPLASY Registration No. 202410040).

Correlation of pain perception and fentanyl consumption after major abdominal surgery with CGRP 4218T/C polymorphism: A prospective interventional study

Background and Aims

Genetic polymorphisms contribute to patients' variability in pain perception and response to opioid treatment. The present study evaluated the association of calcitonin gene-related peptide (CGRP) 4218T/C polymorphisms with fentanyl consumption over 24 h postoperatively in patients after major abdominal surgery.

Methods

Eighty-five patients undergoing major abdominal surgery under general anaesthesia were recruited. For postoperative analgesia, epidural fentanyl and intravenous paracetamol were provided. The CGRP 4218T/C genotype was analysed, and the association between the genotype of the patient and the total consumption of fentanyl in the first 24 h after surgery was assessed. The association between different genotypes, the severity of postoperative pain and the side effects of opioids were also studied.

Results

Our study population distribution included 52.9% of the T/T genotype (wild homozygote), 35.3% of the T/C genotype (heterozygote) and 11.8% of the C/C genotype (mutant homozygote). Mean (standard deviation) total fentanyl consumption in the first 24 h was found to be highest in the C/C group (212.0 [7.5] μg), followed by the T/T group (182.8 [9.9] μg) and was the least in the T/C group (159.6 [7.5] μg). The C/C group reported higher pain scores in all the study periods. There was no significant difference in the side effects of opioids, such as nausea, vomiting, sedation among different genotypes of CGRP 4218T/C.

Conclusion

The polymorphism of CGRP 4218T/C affects postoperative pain perception and analgesic consumption. Patients with the C/C genotype had higher postoperative fentanyl consumption and pain scores.

Cerebral Edema in Traumatic Brain Injury: a Historical Framework for Current Therapy

PURPOSE OF REVIEW

The purposes of this narrative review are to (1) summarize a contemporary view of cerebral edema pathophysiology, (2) present a synopsis of current management strategies in the context of their historical roots (many of which date back multiple centuries), and (3) discuss contributions of key molecular pathways to overlapping edema endophenotypes. This may facilitate identification of important therapeutic targets.

RECENT FINDINGS

Cerebral edema and resultant intracranial hypertension are major contributors to morbidity and mortality following traumatic brain injury. Although Starling forces are physical drivers of edema based on differences in intravascular vs extracellular hydrostatic and oncotic pressures, the molecular pathophysiology underlying cerebral edema is complex and remains incompletely understood. Current management protocols are guided by intracranial pressure measurements, an imperfect proxy for cerebral edema. These include decompressive craniectomy, external ventricular drainage, hyperosmolar therapy, hypothermia, and sedation. Results of contemporary clinical trials assessing these treatments are summarized, with an emphasis on the gap between intermediate measures of edema and meaningful clinical outcomes. This is followed by a brief statement summarizing the most recent guidelines from the Brain Trauma Foundation (4th edition). While many molecular mechanisms and networks contributing to cerebral edema after TBI are still being elucidated, we highlight some promising molecular mechanism-based targets based on recent research including SUR1-TRPM4, NKCC1, AQP4, and AVP1.

SUMMARY

This review outlines the origins of our understanding of cerebral edema, chronicles the history behind many current treatment approaches, and discusses promising molecular mechanism-based targeted treatments.

Correlation of P2RX7 gene rs1718125 polymorphism with postoperative fentanyl analgesia in patients with lung cancer

The aim of this study was to investigate the association between purinergic receptor P2X7 (P2RX7) gene rs1718125 polymorphism and analgesic effect of fentanyl after surgery among patients with lung cancer in a Chinese Han population.A total of 238 patients with lung cancer who received resection were enrolled in our study. The genotype distributions of P2RX7 rs1718125 polymorphism were detected by polymerase chain reaction and direct sequencing. Postoperative analgesia was performed by patient-controlled intravenous analgesia, and the consumption of fentanyl was recorded. The postoperative pain was measured by visual analog scale (VAS). Differences in postoperative VAS score and postoperative fentanyl consumption for analgesia in different genotype groups were analyzed by analysis of variance assay.The frequencies of GG, GA, and AA genotypes were 46.22%, 44.96%, and 8.82%, respectively. After surgery, the postoperative VAS score of GA group was significantly high in the period of analepsia after general anesthesia and at 6 hours after surgery (P = .041 and P = .030, respectively), while AA group exhibited obviously high in the period of analepsia after general anesthesia (P < .001), at postoperative 6 hours (P = .006) and 24 hours (P = .016). Moreover, the patients carrying GA and AA genotypes needed more fentanyl to control pain within 48 hours after surgery (P < .05 for all).P2RX7 gene rs1718125 polymorphism is significantly associated with postoperative pain and fentanyl consumption in patients with lung cancer.