Neurobiology of Propofol Addiction and Supportive Evidence: What Is the New Development?

Effect of propofol and ciprofol on the euphoric reaction in patients with painless gastroscopy: A prospective randomized controlled trial

Objective

To explore the effects of propofol and ciprofol on patient euphoric reactions during sedation in patients undergoing gastroscopy and to investigate potential factors that may influence euphoric reactions in patients.

Methods

A total of 217 patients were randomly divided into two groups: the propofol group (P group, n = 109) and the ciprofol group (C group, n = 108). The patients in the P group were given 2 mg/kg propofol, and those in the C group were given 0.5 mg/kg ciprofol. The patients were assessed using the Addiction Research Center Inventory-Chinese Version (ARCI-CV) to measure euphoric reactions at three time points: preexamination, 30 min after awakening, and 1 week after examination. Anxiety, depression, and sleep status were evaluated using appropriate scales at admission and 1 week after the examination. The dream rate, sedative effects, vital sign dynamics, and adverse reactions were documented during the sedation process.

Results

After 30 min of awakening, the P group and C group showed no statistically significant differences in the mean morphine-benzedrine group (MBG) score (8.84 vs. 9.09, P > 0.05), dream rate (42.2 % vs. 40.7 %, P > 0.05), or MBG score one week after the examination (7.04 vs. 7.05, P > 0.05). The regression analysis revealed that sex, dream status, Alcohol Use Disorders Identification Test (AUDIT) score, and examination time had notable impacts on the MBG-30 min score. No statistically significant differences were observed in sedative effects, anxiety, depression, or sleep status between the two groups (P > 0.05). The incidence of injection pain and severe hypotension was significantly lower in the C group (P < 0.05), and hemodynamics and SpO2 were more stable during sedation (P < 0.05).

Conclusion

There was no significant difference between propofol and ciprofol in terms of euphoria experienced by patients after sedation in patients undergoing gastroscopy. Ciprofol has demonstrated addictive potential similar to that of propofol, warranting careful attention to its addictive potential during clinical application.

Non-Opioid Anesthetics Addiction: A Review of Current Situation and Mechanism

Drug addiction is one of the major worldwide health problems, which will have serious adverse consequences on human health and significantly burden the social economy and public health. Drug abuse is more common in anesthesiologists than in the general population because of their easier access to controlled substances. Although opioids have been generally considered the most commonly abused drugs among anesthesiologists and nurse anesthetists, the abuse of non-opioid anesthetics has been increasingly severe in recent years. The purpose of this review is to provide an overview of the clinical situation and potential molecular mechanisms of non-opioid anesthetics addiction. This review incorporates the clinical and biomolecular evidence supporting the abuse potential of non-opioid anesthetics and the foreseeable mechanism causing the non-opioid anesthetics addiction phenotypes, promoting a better understanding of its pathogenesis and helping to find effective preventive and curative strategies.

Factors associated with euphoria in a large subset of cases using propofol sedation during gastrointestinal endoscopy

Background

The utilization of Propofol, a widely used intravenous sedative or anesthetic, is characterized by its quick onset, predictable control, and fleeting half-life during both general anesthesia and intensive care unit sedation. Recent evidence, however, has highlighted propofol's propensity to induce euphoria, particularly in patients undergoing painless procedures such as gastrointestinal or gastric endoscopy. Given its widespread use in patients undergoing such procedures, this study aims to investigate the clinical evidence and factors that may influence propofol-induced euphoria in these settings.

Methods

The Addiction Research Center Inventory-Chinese Version (ARCI-CV) scale was administered to 360 patients undergoing gastric or gastrointestinal endoscopy using propofol as a sedative. Patient characteristics including past medical history, depression, anxiety, alcohol abuse, and sleep disturbance were recorded through history taking and assessment using various questionnaires prior to the examination. The euphoric and sedative statuses were assessed at 30 min and 1 week post-examination.

Results

The experimental results of a survey of 360 patients who underwent gastric or gastrointestinal endoscopy using propofol showed that the mean Morphine-Benzedrine Group (MBG) score before the procedure and after 30 min of the procedure was 4.23 and 8.67, respectively. The mean Pentobarbital-Chlorpromazine-Alcohol Group (PCAG) score before the procedure and after 30 min of the procedure was 3.24 and 6.22, respectively. These results showed that both MBG and PCAG scores increased significantly after the procedure. Certain factors, such as dreaming, propofol dose, duration of anesthesia, and etomidate dose, were all correlated with MBG both at 30 min and 1 week after the examination. In addition, etomidate had an effect of decreasing MBG scores and increasing PCAG scores both at 30 min and 1 week after the examination.

Conclusion

Taken together, propofol may elicit euphoria and potentially contribute to propofol addiction. There are several risk factors for the development of propofol addiction, including dreaming, propofol dose, duration of anesthesia, and etomidate dose. These findings suggest that propofol may have a euphoric effect and may have the potential for drug addiction and abuse.

Pre- and peri-operative clinical information, physiological observations and outcome measures following flexible ureterorenoscopy (FURS), for the treatment of kidney stones. A single-centre observational clinical pilot-study in 51 patients

BACKGROUND

Kidney stone disease contributes to a significant proportion of routine urological practice and remains a common cause of worldwide morbidity. The main aim of this clinical-pilot study was to investigate the effect of flexible ureterorenoscopy (FURS) on pre- and peri-operative clinical information, physiological observations and outcome measures.

METHODS

Included were 51 patients (31 males, 20 females), who underwent elective FURS, for the treatment of kidney stones. Pre-operative and peri-operative clinical information, and post-operative physiological observations and outcome measures were collected using a standard case report form. Pre-operative clinical information included age, gender, BMI, previous history of stone formation and hypertension. Pre-operative stone information included the size (mm), Hounsfield units (HU), laterality and intra-renal anatomical location. Peri-operative surgical details included surgical time in minutes; Laser use; Duration and energy of laser; and post-operative stenting. The physiological outcomes measured included systolic and diastolic blood pressure (mmHg), Likert pain score, temperature, heart rate (bpm) and respiration rate (bpm). Following initial descriptive analysis, a series of Pearson's correlation coefficient tests were performed to investigate the relationship between surgical factors other variable factors.

RESULTS

A series of significant, positive correlations were observed between; age and surgical time (p = 0.014, r = 0.373); stone size and Hounsfield unit (p = 0.029, r = 0.406); surgical time and duration of laser (p < 0.001, r = 0.702); surgical time and BMI (p = 0.035, r = 0.322); baseline heart rate and Hounsfield unit (p = 0.026, r = - 0.414); base line heart rate and BMI (p = 0.030, r = 0.307).; heart rate at 120-min post FURS and age (p = 0.038, r = - 0.308); baseline pain score and BMI (p = 0.010, r = 0.361); baseline respiration rate and BMI (p = 0.037, r = 0.296); respiration rate at 240-min post FURS and BMI (p = 0.038, r = 0.329); respiration rate at 120 min post FURS and age (p = 0.022, r = - 0.330). Four patients developed post-operative complications (3-UTIs with urinary retention, 1-urosepsis).

CONCLUSIONS

We report that following FURS there is an association between various physiological, clinical and surgical parameters. Although these correlations are weak, they warrant further investigation as these may be linked with untoward complications, such as infection that can occur following FURS. This data, however, will need to be validated and reproduced in larger multi-centre studies.

Subanesthetic Dose of Propofol Activates the Reward System in Rats

BACKGROUND

Propofol has addictive properties, even with a single administration, and facilitates dopamine secretion in the nucleus accumbens (NAc). Activation of the dopaminergic circuits of the midbrain reward system, including the ventral tegmental area (VTA) and NAc, plays a crucial role in addiction. However, the effects of propofol on synaptic transmission and biochemical changes in the VTA-NAc circuit remain unclear.

METHODS

We investigated the effects of subanesthetic doses of propofol on rat VTA neurons and excitatory synaptic transmission in the NAc using slice patch-clamp experiments. Using immunohistochemistry and western blot analyses, we evaluated the effects of intraperitoneal propofol administration on the expression of addiction-associated transcription factor ΔFosB (truncated form of the FBJ murine osteosarcoma viral oncogene homolog B protein) in the NAcs in 5-week-old rats.

RESULTS

In the current-clamp mode, a subanesthetic dose (0.5-5 µmol/L) of propofol increased the action potential frequency in about half the VTA neurons (excited neurons: control: 9.4 ± 3.0 Hz, propofol 0.5 µmol/L: 21.5 ± 6.0 Hz, propofol 5 µmol/L: 14.6 ± 5.3 Hz, wash: 2.0 ± 0.7 Hz, n = 14/27 cells; unchanged/suppressed neurons: control: 1.68 ± 0.94 Hz, propofol 0.5 µmol/L: 1.0 ± 0.67 Hz, propofol 5 µmol/L: 0.89 ± 0.87 Hz, wash: 0.16 ± 0.11 Hz, n = 13/27 cells). In the voltage-clamp mode, about half the VTA principal neurons showed inward currents with 5 µmol/L of propofol (inward current neurons: control: -20.5 ± 10.0 pA, propofol 0.5 µmol/L: -62.6 ± 14.4 pA, propofol 5 µmol/L: -85.2 ± 18.3 pA, propofol 50 µmol/L: -17.1 ± 39.2 pA, washout: +30.5 ± 33.9 pA, n = 6/11 cells; outward current neurons: control: -33.9 ± 14.6 pA, propofol 0.5 µmol/L: -29.5 ± 16.0 pA, propofol 5 µmol/L: -0.5 ± 20.9 pA, propofol 50 µmol/L: +38.9 ± 18.5 pA, washout: +40.8 ± 32.1 pA, n = 5/11 cells). Moreover, 0.5 µmol/L propofol increased the amplitudes of evoked excitatory synaptic currents in the NAc, whereas >5 µmol/L propofol decreased them (control: 100.0 ± 2.0%, propofol 0.5 µmol/L: 118.4 ± 4.3%, propofol 5 µmol/L: 98.3 ± 3.3%, wash [within 10 min]: 70.7 ± 3.3%, wash [30 minutes later]: 89.9 ± 2.5%, n = 13 cells, P < .001, Dunnett's test comparing control and propofol 0.5 µmol/L). Intraperitoneally administered subanesthetic dose of propofol increased ΔFosB expression in the NAc, but not in VTA, 2 and 24 hours after administration, compared with the Intralipid control group (propofol 2 hours: 0.94 ± 0.15, 24 hours: 0.68 ± 0.07; Intralipid 2 hours: 0.40 ± 0.03, 24 hours: 0.37 ± 0.06, P = .0002 for drug in the 2-way analysis of variance).

CONCLUSIONS

Even a single administration of a subanesthetic dose of propofol may cause rewarding change in the central nervous system. Thus, there is a potential propofol rewarding effect among patients receiving anesthesia or sedation with propofol, as well as among health care providers exposed to propofol.

Propofol as a Drug of Diversion: Changing Disposal Practices to Reduce Risk

BACKGROUND

Propofol is a drug of diversion because of its high-volume use, lack of prescribed control mechanisms, and accessibility. As a result, intensive care unit nurses and other health care professionals are placed at unnecessary risk. Decreasing the risk of drug diversion can save lives, licenses, and livelihoods.

LOCAL PROBLEM

Objectives were to reduce the risk of drug diversion and diminish the environmental impact of medication discarded down the sink. Disposing of residual propofol into activated carbon pouches was successful and sustainable in operating rooms at the study institution. Literature findings supported this intervention because of propofol's potential for abuse, ongoing diversion events, ease of access, poor control mechanisms, lack of standardization, excessive waste, and ecological impact.

METHODS

The intensive care unit with the highest propofol use was selected to replicate the propofol disposal process used in the operating rooms. Activated carbon pouches and bottle cap removal tools were located in each intensive care unit room at the nurses' workstation for ease of use. Audits of unsecured waste bins and staff surveys of institutional policy awareness, disposal processes, barriers, and concerns were completed before and after the intervention.

RESULTS

Survey results determined significant concern for drug diversion risk. The pilot project displayed success: 44.1% of propofol bottles in waste bins were full before the intervention and 0% were full afterward.

CONCLUSION

Following institutional approval, this propofol disposal process was replicated in all intensive care units and the emergency department in the study institution.

Propofol but not dexmedetomidine produce locomotor sensitization via nitric oxide in rats

RATIONALE

The abused potential of some anesthetics has been debated. Measurement of locomotor sensitization is a better way to detect the neurobehavioral plasticity of addiction.

OBJECTIVES

The present study aims to explore whether propofol and dexmedetomidine are capable of inducing locomotor sensitization.

METHODS

Male Wistar rats (250-300 g) were the subjects (n = 8 for each group). Propofol (20 and 40 mg/kg) and dexmedetomidine (2.5-20 μg/kg) or saline were injected to rats intraperitoneally (IP), and their locomotor activities were recorded for 15 min. Consequently, L-NAME (30 and 60 mg/kg)-a nitric oxide (NO) inhibitory agent-was injected to rats 30 min before propofol (40 mg/kg) or saline injections, and the locomotor activity was recorded. The process was carried out for 13 days, with 7 sessions applied every other day.

RESULTS

Dexmedetomidine did not produce any significant locomotor sensitization. While propofol (20 mg/kg) produced a significant locomotor sensitization in the last treatment session (day 13), at the higher dose, it prompted a significant locomotor sensitization from the 3rd treatment session. L-NAME blocked propofol-induced locomotor hyperactivity and sensitization significantly without producing any noteworthy changes on the locomotor activity during the testing period of 13 days when administered alone.

CONCLUSIONS

Our results suggest that propofol but not dexmedetomidine produced a significant locomotor sensitization via central nitrergic system. Dexmedetomidine may have a lesser psychostimulant type addictive potential than propofol. Sensitization development by propofol implies that this drug might be effective on the neuroadaptive processes associated with a stimulant type of dependence.

[Sensations of patients and their satisfaction during awake craniotomy]

Awake craniotomy (AC) has gained fantastic popularity over the past years. This approach is no longer the destiny of only highly specialized neurosurgical centers. Technical features of AC are completely developed. However, certain aspects of patients' sensations and their satisfaction are still unclear. The review is devoted to these issues. It was shown that AC is positively evaluated by the vast majority of patients. Many patients would choose this technique for redo surgery. However, there are certain important details that can adversely affect satisfaction of patients. Thus, these features should be considered in AC.

Propofol Modulates Early Memory Consolidation in Humans

Maintenance of memory across time is crucial for adaptive behavior. Current theories posit that the underlying consolidation process depends on stabilization of synapses and reorganization of interactions between hippocampus and neocortex. However, the temporal properties of hippocampal-neocortical network reconfiguration during consolidation are still a matter of debate. Translational research on this issue is challenged by the paucity of techniques to transiently interfere with memory in the healthy human brain. Here, we report a neuro-pharmacological approach with the GABA_Aergic anesthetic propofol and a memory task sensitive to hippocampal dysfunction. Patients undergoing minor surgery learned word lists before injection of an anesthetic dose of propofol. Results show that administration of the drug shortly after learning (∼13 min) impairs recall after awakening but spares recognition. By contrast, later administration (∼105 min) has no effect. These findings suggest significant changes in memory networks very early after learning that are decisive for later recall. Propofol general anesthesia provides an experimental tool to modulate the first steps of hippocampus-mediated memory consolidation in humans.

Motivation, risk-taking and sensation seeking behavior in propofol anesthesia exposed peripubertal rats

Adolescent neurodevelopment confer vulnerability to the actions of treatments that produce adaptations in neurocircuitry underlying motivation, impulsivity and reward. Considering wide usage of a sedative-hypnotic agent propofol in clinical practice, we examined whether propofol is a challenging treatment for peripubertal brain. Motivation/hedonic behavior (sucrose preference test), approach/avoidance behavior (elevated plus maze test) and response to dissociative drug phencyclidine (PCP) were studied in peripubertal rats (the rodent model of periadolescence) after propofol anesthesia exposure (PAE). Neurodegeneration (Fluoro-Jade staining) and the expression of proteins (Western blot) involved in excitatory synaptic transmission and activity-dependent synaptic stabilization in the medial prefrontal cortex (mPFC) and striatum (components of motivation/reward circuitry; process both appetitive and aversive events) were examined as well. In peripubertal rats PAE produced 1) transient brain-region specific changes in the expression of N-methyl-d-aspartate (NMDA) receptor subunits NR2A and NR2B, PSD-95 and N-cadherin, without neurotoxicity, 2) hyperlocomotor response to PCP, 3) no changes in preference for palatable 1% sucrose solution and a decrease in food eaten, 4) preference for 20% sucrose solution without changes in food eaten, 5) stretch-attended postures and open arms entries in the elevated plus maze test. Overall, these novel findings show that PAE leaves transient synaptic trace recognized as early form of synaptic plasticity related to passive drug exposure in the brain systems implicated in motivation/reward, increases drug-responsiveness, favors risk-taking and preference of novel/intense stimuli repairing otherwise present motivational deficiency. These findings accentuate multifaceted response to propofol in peripuberty and the importance of environmental stability for the most favorable neurobehavioral recovery.

Alcohol Interaction with Cocaine, Methamphetamine, Opioids, Nicotine, Cannabis, and γ-Hydroxybutyric Acid

Millions of people around the world drink alcoholic beverages to cope with the stress of modern lifestyle. Although moderate alcohol drinking may have some relaxing and euphoric effects, uncontrolled drinking exacerbates the problems associated with alcohol abuse that are exploding in quantity and intensity in the United States and around the world. Recently, mixing of alcohol with other drugs of abuse (such as opioids, cocaine, methamphetamine, nicotine, cannabis, and γ-hydroxybutyric acid) and medications has become an emerging trend, exacerbating the public health concerns. Mixing of alcohol with other drugs may additively or synergistically augment the seriousness of the adverse effects such as the withdrawal symptoms, cardiovascular disorders, liver damage, reproductive abnormalities, and behavioral abnormalities. Despite the seriousness of the situation, possible mechanisms underlying the interactions is not yet understood. This has been one of the key hindrances in developing effective treatments. Therefore, the aim of this article is to review the consequences of alcohol's interaction with other drugs and decipher the underlying mechanisms.

Propofol alleviates hypoxia-induced nerve injury in PC-12 cells by up-regulation of microRNA-153

Background

Although the neuroprotective role of propofol has been identified recently, the regulatory mechanism associated with microRNAs (miRNAs/miRs) in neuronal cells remains to be poorly understood. We aimed to explore the regulatory mechanism of propofol in hypoxia-injured rat pheochromocytoma (PC-12) cells.

Methods

PC-12 cells were exposed to hypoxia, and cell viability and apoptosis were assessed by CCK-8 assay and flow cytometry assay/Western blot analysis, respectively. Effects of propofol on hypoxia-injured cells were measured, and the expression of miR-153 was determined by stem-loop RT-PCR. After that, whether propofol affected PC-12 cells under hypoxia via miR-153 was verified, and the downstream protein of miR-153 as well as the involved signaling cascade was finally explored.

Results

Hypoxia-induced decrease of cell viability and increase of apoptosis were attenuated by propofol. Then, we found hypoxia exposure up-regulated miR-153 expression, and the level of miR-153 was further elevated by propofol in hypoxia-injured PC-12 cells. Following experiments showed miR-153 inhibition reversed the effects of propofol on hypoxia-treated PC-12 cells. Afterwards, we found BTG3 expression was negatively regulated by miR-153 expression, and BTG3 overexpression inhibited the mTOR pathway and AMPK activation. Besides, hypoxia inhibited the mTOR pathway and AMPK, and these inhibitory effects could be attenuated by propofol.

Conclusion

Propofol protected hypoxia-injured PC-12 cells through miR-153-mediataed down-regulation of BTG3. BTG3 could inhibit the mTOR pathway and AMPK activation.