The misuse and abuse of propofol

A comprehensive analysis of propofol abuse, addiction and neuropharmacological aspects: an updated review

This review aims to assess the existing studies on propofol, a relatively new intravenous anesthetic, related to its abuse and addictive potential and to explain the neurobiological and neuropharmacological aspects of propofol addiction. Several neurobiological factors related to complex processes in the brain influence propofol abuse and addiction. In this review, we assessed the literature regarding propofol abuse and addiction, including both experimental and clinical studies. We selected articles from animal studies, case reports, clinical trials, meta-analyses, narrative reviews, and systematic reviews to extract all relevant crucial quantitative data with a measure of neurobiological and neuropharmacological aspects. Thus, the main goal of this study was to investigate the current literature and discuss the association between the central nervous system and propofol abuse and addiction in the context of addictive behavior. Current data suggest that propofol has a strong addictive potential and produces prominent addiction in both animals and humans. Thus, medical practitioners should exercise caution with propofol use, and we argue that this drug should be added to the list of controlled substances.

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.

Propofol misuse in medical professions: a scoping review

PURPOSE

We aimed to describe the current literature concerning propofol misuse in medical professionals, specifically relating to the individual demographics of those misusing propofol and the outcomes of propofol misuse.

METHODS

We conducted a retrospective scoping review of the literature using a modified PRISMA approach. We used MEDLINE, EMBASE, and PsycINFO databases to identify relevant studies based on search terms. Studies describing individual medical professionals misusing propofol were included.

RESULTS

Twenty-four articles describing 88 individual cases of propofol misuse were included for data charting and analysis. Anesthesiologists and certified registered nurse anesthetists were most commonly identified. Death was a common method of identification of misuse, while rehabilitation and death were common final outcomes associated with propofol misuse.

CONCLUSIONS

Despite knowledge of the pharmacokinetic and pharmacodynamic properties of propofol by those misusing this medication, death was a common outcome reported in the literature. Data related to long-term outcomes including re-entry to clinical practice or success of rehabilitation were limited.

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.

Neurons in the Locus Coeruleus Modulate the Hedonic Effects of Sub-Anesthetic Dose of Propofol

Propofol is a worldwide-used intravenous general anesthetic with ideal effects, but hedonic effects of propofol have been reported and cause addictive issue. There is little known about the neurobiological mechanism of hedonic effects of propofol. Increasing researches have shown that the dopaminergic nervous system of the ventral tegmental area (VTA) and the noradrenergic system of locus coeruleus (LC) play a crucial role in hedonic experiences, which are putative sites for mediating the hedonic effects of propofol. In the present study, rat hedonic response scale and place conditioning paradigm were employed to examine the euphoric effects of propofol. In vivo GCaMP-based (AVV-hSyn-GCaMP6s) fiber photometry calcium imaging was used to monitor the real-time neuronal activity in VTA and LC area in rats exhibiting propofol-induced euphoric behaviors. Then DREADDs (designer receptors exclusively activated by designer drugs) modulation using rAAV-hSyn-hM4D(Gi)-EGFP was performed to confirm the neuronal substrate that mediates the euphoric effects of propofol. The score of hedonic facial responses was significantly increased in the 4 mg/kg group compared with that of the 0 mg/kg group. The locomotor activity in the propofol-paired compartment was significantly increased at the 4 mg/kg dose compared with that of the saline-paired group. When compared with the 0 mg/kg group, the place preference increased in the 4 mg/kg group. Administration of 4 mg/kg of propofol triggers reliable increases in GcaMP fluorescence. However, in the VTA GcaMP-expressing rats, administration of 4 mg/kg of propofol did not induce any change of GcaMP signals. The facial score and the place preference, which increased by 4 mg/kg propofol were abolished by chemogenetic inhibition of the neuronal activity in the LC area. Our results suggest that LC noradrenergic neurons, not VTA dopaminergic neurons, are directly involved in the hedonic effects of sub-anesthetic dose of propofol.

Toxicological effects of propofol abuse on the dopaminergic neurons in ventral tegmental area and corpus striatum and its potential mechanisms

This study was aimed at examining propofol- (a known anesthetic) induced emotion-related behavioral disorders in mice, and exploring the possible molecular mechanisms. A total of 60 mice were divided into two groups: control and propofol group. Mice were injected with propofol (150 mg/kg, ip) at 8:00 a.m. (once a day, lasting for 30 days). During the 30 days, loss of righting reflex (LORR) and return of righting reflex (RORR) of mice were recorded every day. At the 1st (T1) and 30th (T2) day of drug discontinuance (T2), 15 mice of each group were selected to perform the open field test; then the mice underwent perfusion fixation, and the midbrain and corpus striatum were separated for immunofluorescence assay with anti-tyrosine hydroxylase (Th) and anti- dopamine transporter (DAT) antibodies. Results showed that after propofol injection, LORR and RORR increased and decreased, respectively. Long-term use of propofol resulted in decreased activities of mice (activity trajectory, line crossing, rearing time, scratching times and defecating frequency). Immunofluorescence assay showed long-term use of propofol induced decrease of Th and DAT. Collectively, our present work suggested long-term abuse of propofol induces neuropsychiatric function impairments, and the possible mechanisms are related to dopamine dyssynthesis via down-regulating tyrosine hydroxylase and dopamine transporter.

Implementation of a new method to track propofol in an endoscopy unit

AIM

Propofol is a widely used anesthesia induction agent and is easily accessible in most healthcare facilities. Unlike regulated or schedule drugs, propofol is inconsistently tracked, leading to inaccurate inventories, incorrect billing, and unrecognized diversion. The goal of this project was to implement a new method of tracking propofol in a single setting, with the aim of accounting for 100% of the drug.

METHODS

For two, 2-week observation periods, data were extracted from an automated medication management system or pharmacy inventory system, anesthesia records, and pharmacy billing sheets for cases in a Gastrointestinal (GI) Endoscopy Unit, and compared pre-implementation and post-implementation of a new tracking and accounting protocol. Variables included amount of propofol inventoried, dispensed, administered, returned, billed, wasted, and missing.

RESULTS

Pre-implementation (n = 300), 10% cases had no record of propofol removal from the automated medication system. Of the 90% that did, 25% had an amount signed out that did not match the amount administered. Thirty-one percent of all propofol was unaccounted for during this 2-week period. Furthermore, 19.7% of cases did not have a billing form located. Post-implementation of the process change, unaccounted for propofol decreased to 26% of all cases (P = ns). The percentage of missing billing forms decreased from 19.7 to 5.8% (P = 0.00).

CONCLUSION

Data suggest notable amounts of propofol were unaccounted for and not billed for in the GI Endoscopy Unit prior to the protocol change. Post-protocol change data reveal modest improved accounting of the medication and significant cost-capture. Improvements may enhance inventory reconciliation, availability of drug stock, and potentially result in a decreased risk of unrecognized diversion.

Propofol sedation during gastrointestinal endoscopy arouses euphoria in a large subset of patients

Background

Propofol is recommended for sedation in gastrointestinal endoscopy (GE), but preliminary data suggest addictive potentials.

Objective

The objective of this article is to evaluate the frequency of predominantly euphoric reaction after GE and patients' subsequent reminiscences.

Methods

Eighty-two patients undergoing elective GE under propofol sedation were enrolled in a prospective observational study. The grade of anxiety, expectation or relief about the examination's result and affective state in terms of cheerfulness, relaxation, activation, sedation and anxiety were surveyed using a numeric rating scale (1 to 10) immediately before (t1), after GE (t2) and seven days (t3) later. Statistics: hierarchical cluster analysis, heat map, χ2 test and paired t test.

Results

Mean propofol dosage was 264 ± 120 mg. Two clusters of mood changes emerged (t1 vs. t2). One (n = 46, 56.1%) was characterized by an unease reaction pattern with equal values regarding cheerfulness, relaxation and anxiety, while relaxation decreased; the other cluster showed a euphoric reaction pattern (n = 36, 43.9%) with markedly increased cheerfulness, relaxation and decreased anxiety. These effects intensified at recall (t3). Despite similar endoscopy results, euphoric cluster patients rated these more positively.

Conclusion

Propofol induces euphoria in nearly half of the patients undergoing elective GE with persisting, even enhanced reminiscence (germanctr.de, trial number DRKS00011202).

Non-opioid anesthetic drug abuse among anesthesia care providers: a narrative review

PURPOSE

The objective of this narrative review is to provide an overview of the problem of non-opioid anesthetic drug abuse among anesthesia care providers (ACPs) and to describe current approaches to screening, therapy, and rehabilitation of ACPs suffering from non-opioid anesthetic drug abuse.

SOURCE

We first performed a search of all literature available on PubMed prior to April 11, 2016. The search was limited to articles published in Spanish and English, and the following key words were used: anesthesiology, anesthesia personnel, AND substance-related disorders. We also searched Ovid MEDLINE^® databases from 1946-April 11, 2016 using the following search terms: anesthesiology OR anesthesia, OR nurse anesthetist OR anesthesia care provider OR perioperative nursing AND substance-related disorders.

PRINCIPAL FINDINGS

Despite an increased awareness of drug abuse among ACPs and improvements in preventive measures, the problem of non-opioid anesthetic drug abuse remains significant. While opioids are the most commonly abused anesthesia medications among ACPs, the abuse of non-opioid anesthetics is a significant cause of morbidity, mortality, and professional demise.

CONCLUSION

Early detection, effective therapy, and long-term follow-up help ACPs cope more effectively with the problem and, when possible, resume their professional activities. There is insufficient evidence to determine the ability of ACPs to return safely to anesthesia practice after rehabilitation, though awareness of the issue and ongoing treatment are necessary to minimize patient risk from potentially related clinical errors.

Locomotor stimulation by acute propofol administration in rats: Role of the nitrergic system

BACKGROUND

The addictive potential of propofol has been scientifically discussed. Drugs' psychostimulant properties that can be assessed via measurements of locomotor activity are linked to their addictive properties. No studies that have investigated the effects of propofol on locomotor activity have been reported to date. The present study sought to investigate the effects and possible mechanisms of action of propofol on locomotor activity in rats.

METHODS

Adult male albino Wistar rats (250-330g) were used as subjects. The locomotor activities of the rats were recorded for 30min immediately following intraperitoneal administration of propofol (20 and 40mg/kg), saline or vehicle (n=8 for each group). NG-nitro arginine methyl ester (l-NAME, 15-60mg/kg), a nitric oxide (NO) synthase inhibitor, and haloperidol (0.125-5mg/kg), a non-specific dopamine receptor antagonist, were also administered to other groups of rats 30min prior to the propofol (40mg/kg) injections, and locomotor activity was recorded for 30min immediately after propofol administration (n=8 for each group).

RESULTS

Propofol produced significant increases in the locomotor activities of the rats in the first 5min of the observation period [F(2,21)=9.052; p<0.001]. l-NAME [F(4,35)=3.112; p=0.02] but not haloperidol [F(4,35)=2.440; p=0.067] pretreatment blocked the propofol-induced locomotor hyperactivity. l-NAME did not cause any significant change in locomotor activity in naïve rats [F(2,21)=0.569; p=0.57].

CONCLUSIONS

Our results suggest that propofol might cause a short-term induction of locomotor activity in rats and that this effect might be related to nitrergic but not dopaminergic mechanisms.

Increased use in propofol and reported patterns of adverse events among anesthetics in Korea

BACKGROUND

Propofol is an addictive drug, and the problem of its abuse and dependence has occurred. To compare the safety profiles of propofol and other similar anesthetics such as diazepam, lorazepam, and midazolam, we evaluated their uses and related adverse drug reactions (ADRs) using Korean Adverse Event Reporting System (KAERS) data.

METHODS

The domestic consumption data and the ADR reports of four anesthetics from 2008 to 2012 were retrieved. ADR proportions were calculated using defined daily dose/1000 inhabitants/day (DID) for the denominator. The patient's characteristics were compared among the four drugs statistically, and the types of ADRs were analyzed.

RESULTS

The consumption and ADR reports increased during the study period, particularly in the cases of propofol and midazolam. Lorazepam showed the highest overall and serious ADR proportions (220.81 reports/DID, 58.47 reports/DID, respectively); however, with respect to death proportion, propofol was the first (19.21 reports/DID). Also, ADRs related to drug addiction were mainly observed in the propofol group.

CONCLUSIONS

Four anesthetics were different with regard to the consumption and proportion or the type of ADRs. The use of propofol increased more than 2 times, and propofol showed the highest ADR proportions in death and drug addiction cases among the four anesthetics.

[Life-threatening fentanyl and propofol addiction: interview with a survivor]

Anesthesiologists have a well-known increased risk of substance abuse including the intravenous administration of opioids and propofol. However, katamnestic reports from the point of view of propofol-addicted anesthesiologists themselves are missing which would aid a better understanding of the dynamics and progress of addiction. This article presents an interview with a formerly addicted female anesthesiologist who after long-term abuse with oral tilidine combined with naloxone switched to intravenous administration of fentanyl and later on propofol. Several life-threatening incidents occurred but after some severe setbacks occupational rehabilitation outside the field of anesthesiology was successful following inpatient treatment. This case shows exemplarily in accordance with the current literature that warning signs in addicted physicians are often ignored by colleagues and supervisors and rehabilitation is possible under professional therapy and continuous surveillance. Additionally, this case emphasizes the necessity of controlling the distribution of propofol to reduce the life-threatening professional risk to anesthesiologists.

Altered states: psychedelics and anesthetics

The psychedelic experience has been reported since antiquity, but there is relatively little known about the underlying neural mechanisms. A recent neuroimaging study on psilocybin revealed a pattern of decreased cerebral blood flow and functional disconnections that is surprisingly similar to that caused by various anesthetics. In this article, the authors review historical examples of psychedelic experiences induced by general anesthetics and then contrast the mechanisms by which these two drug classes generate altered states of consciousness.