Anesthesiologist addicted to propofol

Simple quantification of propofol and its metabolites in blood and urine using gas chromatography-tandem mass spectrometry (GC-MS/MS)

An analytical method which was used for the simultaneous detection and quantification of propofol and its metabolites in human blood and urine by gas chromatography-tandem mass spectrometry (GC-MS/MS) was newly established and applied to authentic human samples obtained from the deceased. The QuEChERS method was employed, and then analyzed by GC-MS/MS. We separately used sulfatase and β-glucuronidase to hydrolyze the urine sample and calculated the increase of propofol and 4-hydroxypropofol before and after the hydrolysis. The results of urinary concentrations in urine from the subject were: 4.88 μg/mL for propofol, 0.53 μg/mL for 4-hydroxypropofol, 3.35 μg/mL for propofol-glucuronide, 0.31 μg/mL for the total concentration of 1-(2,6-diisopropyl-1,4-quinol)-glucuronide plus 4-(2,6-diisopropyl-1,4-quinol)-glucuronide, and 0.39 μg/mL for 4-(2,6- diisopropyl-1,4-quinol)-sulfate. The lower limit of quantification was 10 ng/mL for all determined compounds; the extraction recoveries were not less than 57.2 %. Intraday and interday precisions and accuracies were all less than 10 %. The calibration curves for propofol and 4-hydroxypropofol in human urine showed the correlation values of not less than 0.999; propofol and 4-hydroxypropofol in blood also presented good linearities in the concentration ranges of 0.1-10 μg/mL. The two compounds had good stability within 7 days at 25, 4, and -20 ℃. To our knowledge, this is the first trial to establish a simple and reliable method to simultaneously detect and quantify of propofol and its phase I and II metabolites in human blood and urine samples by GC-MS/MS.

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.

Involvement of the ERK signaling pathways in the NAc in propofol-seeking behavior induced by cues in rats

Propofol, an intravenous short-acting anesthetic, has the potential to induce craving and relapse. Accumulated evidence demonstrates that extracellular signal-regulated kinase (ERK) plays an essential role in drug reward and relapse. In the previous study, we demonstrated that the ERK signaling pathways in the Nucleus accumbens (NAc) were involved in propofol reward. However, the role of the ERK signaling pathways in propofol relapse is still unknown. We first trained rats to self-administer propofol for 14 days, then evaluated propofol-seeking behavior of relapse induced by a contextual cues and conditioned cues after 14-day withdrawal. Meanwhile, MEK inhibitor U0126 was used to investigate the role of the ERK signal pathways in propofol-seeking behavior induced by contextual cues and conditioned cues. Results showed that the number of active nose-poke responses in propofol-seeking behavior induced by conditioned cues was much higher compared to contextual cues. U0126 (5.0 μg/side, Lateral Ventricle (LV)) pretreatment significantly decreased the active responses induced by conditioned cues, which was associated with a large decline in the expression of p-ERK in the NAc. Moreover, microinjectionofU0126 (2.0 μg/side) in the NAc also attenuated the active responses of propofol-seeking behavior. Additionally, microinjections with U0126 in the LV (5.0 μg/side) or NAc (2.0 μg/side) both failed to alter sucrose self-administration or locomotor activity of rats. Therefore, we conclude that ERK phosphorylation in the NAc maybe involved in propofol relapse.

[Propofol: use, toxicology and assay features]

The study objective is to review the literature on the use, pharmacological properties, toxicology, and assay methods for intravenous anesthetic propofol. The scope and forms of propofol use, its pharmacokinetics, biotransformation features, which occurs more than 90% in the liver, and side effects associated with propofol use for anesthesia, are addressed. Propofol infusion syndrome (also known as PrIS) and deaths from propofol overdose due to medical errors, abuse, suicide attempts, and homicide are reported. Propofol identification and assay methods based on high-performance liquid chromatography (HPLC), gas chromatography with mass spectrometry (GC-MS), and liquid chromatography (LC) are described. The features of the methods performance are outlined; biological materials (the study objects) are listed: mainly blood and plasma, as well as urine, bile, hair, etc. The relevance of a comprehensive forensic chemical study of propofol is indicated, though there are few forensic studies of propofol.

The role of NMDA receptors in rat propofol self-administration

BACKGROUND

Propofol is among the most frequently used anesthetic agents, and it has the potential for abuse. The N-methyl-D-aspartate (NMDA) receptors are key mediators neural plasticity, neuronal development, addiction, and neurodegeneration. In the present study, we explored the role of these receptors in the context of rat propofol self-administration.

METHODS

Sprague-Dawley Rats were trained to self-administer propofol (1.7 mg/kg/infusion) using a fixed-ratio (FR) schedule over the course of 14 sessions (3 h/day). After training, rats were intraperitoneally administered the non-competitive NDMA receptor antagonist MK-801, followed 10 min later by a propofol self-administration session.

RESULTS

After training, rats successfully underwent acquisition of propofol self-administration, as evidenced by a significant and stable rise in the number of active nose-pokes resulting in propofol administration relative to the number of control inactive nose-pokes (P < 0.01). As compared to control rats, rats that had been injected with 0.2 mg/kg MK-801 exhibited a significantly greater number of propofol infusions (F (3, 28) = 4.372, P < 0.01), whereas infusions were comparable in the groups administered 0.1 mg/kg and 0.4 mg/kg of this compound. In addition, MK-801 failed to alter the numbers of active (F (3, 28) = 1.353, P > 0.05) or inactive (F (3, 28) = 0.047, P > 0.05) responses in these study groups. Animals administered 0.4 mg/kg MK-801 exhibited significantly fewer infusions than animals administered 0.2 mg/kg MK-801 (P = 0.006, P < 0.01). In contrast, however, animals in the 0.4 mg/kg MK-801 group displayed a significant reduction in the number of active nose-poke responses (F (3, 20) = 20.8673, P < 0.01) and the number of sucrose pellets (F (3, 20) = 23.77, P < 0.01), while their locomotor activity was increased (F (3, 20) = 22.812, P < 0.01).

CONCLUSION

These findings indicate that NMDA receptors may play a role in regulating rat self-administration of propofol.

The Anesthesiologist's Armamentarium: From Recreation to Medication and Back

For millennia, mankind has sought a means of altering consciousness, often aided by naturally occurring elements. Psychotropic substances have been an integral part of spiritual, medicinal, and recreational aspects of life. The origin of anesthesiology stems directly from the use of recreational drugs; early inhaled anesthetics were first used as a means of entertainment. Hence, it is no surprise that many medications in the anesthesiologist's armamentarium are diverted for recreational use. In the 172 years following the first successful public demonstration of ether anesthesia, many drugs with abuse potential have been introduced to the practice of anesthesia. Although anesthesiologists are aware of the abuse potential of these drugs, how these drugs are obtained and used for recreational purposes is worthy of discussion. There are articles describing the historical and recreational use of specific drug classes. However, to the best of our knowledge, this is the first comprehensive review focusing on the breadth of drugs used by anesthesiologists.

An outbreak of HIV infection among people who inject drugs linked to injection of propofol in Taiwan

INTRODUCTION

The aim of this study was to report an HIV outbreak related to propofol-injection and the impact of regulating propofol on the HIV epidemic among people who inject drugs (PWID).

METHODS

A retrospective cohort study of 252 PWID who were diagnosed with an HIV infection between 2014 and 2017 in Taiwan. The propofol information was collected by routine epidemic surveillance and interviews. We linked several national databases to collect other related factors, including methadone maintenance treatment (MMT) attendance and incarceration. The serums were tested for recent infection by the LAg-avidity EIA assay and relationship of the trains by the Phylogenetic tree analysis. Analyses were conducted using the R Surveillance package for retrospective modeling for outbreak detection. A multiple logistic regression was used to evaluate the association between propofol-injection and other related factors.

RESULTS

There were 28 cases reported with propofol-injection, all of which were reported in Central Taiwan. A total of 11 (50%) cases among 22 propofol-injectors with serums were recent infections, which were higher than that 33 (23.4%) of non-propofol group. The phylogenetic tree indicated that 6 propofol-injectors were grouped together with the same cluster in circular. The HIV epidemic curve among PWID revealed an outbreak of 82 in 2015, which then decreased to 43 in 2016 after propofol began to be regulated as a Schedule 4 controlled drug in August 2015. In a multiple logistic regression, attendance at methadone clinics was associated with a significantly higher risk for propofol-injection (adjusted OR = 2.43, 95% CI = 0.98-5.98), and HIV reported in the year 2015 was associated with an increased risk of propofol-injection (adjusted OR = 4, 95% CI = 1.08-14.86).

CONCLUSIONS

Our data indicate that the government regulation of propofol as a controlled drug strategy was associated with significant reduction in the spread of HIV among PWID.

Dopamine D1 Receptor Within Basolateral Amygdala Is Involved in Propofol Relapse Behavior Induced by Cues

Propofol has been proven to be potentially abused by humans and laboratory animals; however, studies that have examined propofol relapse behavior are limited, and its underlying mechanism remains unclear. In this study, we examined whether basolateral amygdala-specific or systematic administration of the dopamine receptor antagonist alters cue-induced propofol-seeking behaviors in a rat model. Male Sprague-Dawley rats first received 14 days of propofol self-administration training, where active nose poke resulted in the delivery of propofol infusion paired with a tone and light cues. After 1-30 days of forced abstinence, the cue-induced propofol-seeking behaviors were tested in the operant chamber. We demonstrated, for the first time, after a few days of withdrawal from intravenous bolus administration of propofol, propofol-related cues could induce robust reinstatement of drug-seeking behavior. Systematic administration of dopamine D₁ receptor antagonist (SCH-23390) or dopamine D₂ receptor antagonist (spiperone) inhibited propofol relapse behavior induced by drug-related cues. Furthermore, we show that microinfusion of SCH-23390 into basolateral amygdala dose-dependently attenuated cue-induced propofol drug-seeking behavior, whereas infusion of spiperone had no effect on the propofol relapse behavior. Our results reveal the involvement of dopamine receptors within the basolateral amygdala in the cue-induced propofol relapse behavior in rats.

Sevoflurane addiction due to workplace exposure: A case report and literature review

RATIONALE

Anesthesiologists have a well-known increased risk of substance abuse. High-concentration of inhalation anesthetics in exhaled air of operating room personnel is detected. such secondhand exposure produces neurobiological sensitization to the reinforcing effects of inhalation anesthetics.

PATIENT CONCERNS

An addictive young male anesthesiologist who was long-term abuse with sevoflurane after 4 years occupational exposure. A 28-year-old anesthesiologist on duty was found deeply sleep in the locker room and coved his nose with Gauze with high-concentration of sevoflurane. He was found addiction to sevoflurane second time. Several life-threatening incidents occurred including severe aspiration pneumonia. No other addiction was found in his history before he became severely dependent on sevoflurane.

DIAGNOSES

A visual analog scale was employed to assess the severity of craving for sevoflurane and the Benzodiazepine Withdrawal Symptom Scale (BWSQ2)-scale was used to assess sevoflurane withdrawal syndrome(WS).

INTERVENTIONS

First time an opened original sevoflurane container filled with water instead of sevoflurane was handed out for a minute in order to elicit craving and withdrawal symptom in five therapeutic single-sessions. Second time an opened original sevoflurane container filled with sevoflurane instead of water was used as his powerful cur-stimulus and also was handed out for a minute.

OUTCOMES

After professional therapy and continuous surveillance he was rehabilitation and back to work. However, after three weeks he became addiction to sevoflurane again. He showed very sensitive to sevoflurane and switched to other career.

LESSONS

This case emphasizes that secondhand exposure to inhalation anesthetics may be dangerous and increase the life-threatening professional risk to anesthesiologists, although identification of the responsible factor remains difficult. However, the safety of operating room staff should be aroused wide-spread social concern.

Metabolic Profiles of Propofol and Fospropofol: Clinical and Forensic Interpretative Aspects

Propofol is an intravenous short-acting anesthetic widely used to induce and maintain general anesthesia and to provide procedural sedation. The potential for propofol dependency and abuse has been recognized, and several cases of accidental overdose and suicide have emerged, mostly among the health professionals. Different studies have demonstrated an unpredictable interindividual variability of propofol pharmacokinetics and pharmacodynamics with forensic and clinical adverse relevant outcomes (e.g., pronounced respiratory and cardiac depression), namely, due to polymorphisms in the UDP-glucuronosyltransferase and cytochrome P450 isoforms and drugs administered concurrently. In this work the pharmacokinetics of propofol and fospropofol with particular focus on metabolic pathways is fully reviewed. It is concluded that knowing the metabolism of propofol may lead to the development of new clues to help further toxicological and clinical interpretations and to reduce serious adverse reactions such as respiratory failure, metabolic acidosis, rhabdomyolysis, cardiac bradyarrhythmias, hypotension and myocardial failure, anaphylaxis, hypertriglyceridemia, renal failure, hepatomegaly, hepatic steatosis, acute pancreatitis, abuse, and death. Particularly, further studies aiming to characterize polymorphic enzymes involved in the metabolic pathway, the development of additional routine forensic toxicological analysis, and the relatively new field of ‘‘omics” technology, namely, metabolomics, can offer more in explaining the unpredictable interindividual variability.

Glucocorticoid receptor in rat nucleus accumbens: Its roles in propofol addictions

Propofol has been demonstrated as a drug of abuse in humans. Our previous study indicated that dexamethasone, a potent agonist of glucocorticoid receptor (GR), inhibited propofol-maintained rat self-administration behaviors by systematic injection. However, the direct effect of GR in the nucleus accumbens (NAc) on propofol self-administration behavior has not been explored. The propofol-maintained self-administration was established in rats after a successive 3-h daily self-administration of propofol for 14days. On day 15, 30min prior to the last training, rats received one of three doses (0.3, 1.0, or 3.0μg/site) of dexamethasone or vehicle via intra-NAc injection. The number of active nose-poke responses, propofol injections, and inactive nose-poke responses was recorded. Dopamine D1 receptor and c-Fos expressions were detected. Plasma corticosterone level was measured by enzyme-linked immunosorbent assay. Intra-NAc administration of dexamethasone (1.0 and 3.0μg/site) facilitated the active nose-poke responses, which was accompanied by the upregulation of D1 receptor and c-Fos in the NAc. Plasma corticosterone level was not changed in dexamethasone-treated groups. This study provides crucial evidence that GR in the NAc plays an important role in regulating propofol self-administration behaviors in rats, which may be mediated by changes in D1 receptor and c-Fos expressions, and this also needs further examination with GR antagonist in the future.

Effects of propofol on conditioned place preference in male rats: Involvement of nitrergic system

BACKGROUND

Drug-induced conditioned place preference (CPP) is linked to the addictive properties of the drug used. The number of studies that have investigated the effects of propofol on CPP is limited. Research findings suggest that nitric oxide (NO) might play an important role in substance use disorders.

OBJECTIVES

The present study sought to investigate the role of the nitrergic system on the rewarding effects of propofol by using the CPP protocol in rats.

METHODS

The experiment followed habituation, pre-conditioning, conditioning, and post conditioning sessions. Male Wistar albino rats weighing 240-290 g were divided into eight groups: control (saline), propofol (10, 20, and 40 mg/kg), the NO synthase (NOS) inhibitor N^G-nitro-L-arginine methyl ester (L-NAME) alone (30 and 60 mg/kg), and in combination with propofol (30 and 60 mg/kg L-NAME plus 40 mg/kg propofol) (n = 8 for each group). The CPP effects of propofol, L-NAME, saline, and their combinations were evaluated. All the drug and saline administrations were performed by intraperitoneal (ip) injections.

RESULTS

Propofol (10-40 mg/kg) produced CPP that was statistically significant relative to saline. Propofol-induced CPP was significantly reversed by pretreatment with L-NAME. When administered alone, L-NAME did not produce CPP and also did not produce any significant change on locomotor activity of naïve rats.

CONCLUSION

Our results suggest that propofol produces CPP effects in rats and that NO-related mechanisms may be responsible for propofol-induced CPP. Thus, propofol might have the potential to be addictive, and this possibility should be considered during clinical applications of this drug.

Practice guidelines for propofol sedation by non-anesthesiologists: the Korean Society of Anesthesiologists Task Force recommendations on propofol sedation

In South Korea, as in many other countries, propofol sedation is performed by practitioners across a broad range of specialties in our country. However, this has led to significant variation in propofol sedation practices, as shown in a series of reports by the Korean Society of Anesthesiologists (KSA). This has led the KSA to develop a set of evidence-based practical guidelines for propofol sedation by non-anesthesiologists. Here, we provide a set of recommendations for propofol sedation, with the aim of ensuring patient safety in a variety of clinical settings. The subjects of the guidelines are patients aged ≥ 18 years who were receiving diagnostic or therapeutic procedures under propofol sedation in a variety of hospital classes. The committee developed the guidelines via a de novo method, using key questions created across 10 sub-themes for data collection as well as evidence from the literature. In addition, meta-analyses were performed for three key questions. Recommendations were made based on the available evidence, and graded according to the modified Grading of Recommendations Assessment, Development and Evaluation system. Draft guidelines were scrutinized and discussed by advisory panels, and agreement was achieved via the Delphi consensus process. The guidelines contain 33 recommendations that have been endorsed by the KSA Executive Committee. These guidelines are not a legal standard of care and are not absolute requirements; rather they are recommendations that may be adopted, modified, or rejected according to clinical considerations.

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.

A Case Report of the First Propofol Addiction in Turkey

Propofol is a potent anaesthetic drug and also an effective sedative agent. Also, propofol may be used for non-anaesthetic purposes such as the treatment of seizures, migraine and tension headache in clinical practice. It has been abused, particularly among healthcare providers with high mortality rate. This report presents the case of a propofol-dependent patient who was an emergency medicine doctor with no difficulties in obtaining the drug. He himself visited our clinic for the treatment of propofol dependence. We started the patient's treatment with pharmacotherapeutic medicines and individual psychotherapy. Fourteen days after starting the therapy, the patient was discharged from hospital on his own will and he did not attend the follow-up visits in the outpatient clinic. Then, we were informed of his death, which was suspected to have occurred owing to drug intoxication in the hospital in which he worked. Nevertheless, the reason of death was important; the importance of this case report is to provide information regarding the drug's dependence profile. This is the first case report indicating propofol dependence in Turkey. Because of its easy access, rapid onset time and short duration of action, propofol dependence is increasing. We think that adding propofol to the controlled drug list and improving the knowledge of the clinicians regarding its abuse potential may limit the dependence cases.

Clinical and psychological characteristics of propofol abusers in Korea: a survey of propofol abuse in 38, non-healthcare professionals

BACKGROUND

The aim of this study is to investigate the characteristics of propofol abuse based on the results of a survey analysis of abusers among non-healthcare professionals in Korea.

METHODS

Thirty-eight propofol abusers were questioned between October and December 2010, and were enrolled and voluntarily participated in a structured survey consisting of an interview and completing a previously prepared questionnaire. The questionnaire was divided into three distinct parts: part 1 dealt with the history of propofol abuse; part 2 highlighted the problems caused by propofol abuse; and part 3 enquired regarding demographics of abusers.

RESULTS

Thirty-one (81.6%) of the 38 interviewees abused propofol for more than one year. During the last 12 months, 34 (89.0%) received propofol at two or three times a week. The minimum and maximum amounts of propofol (median, range) administered each time were 500 (100, 1000) and 2000 (500, 4000) mg, respectively. Stress relief and the maintenance of a sense of well-being were quoted the most important reasons for the first-time administration of propofol and its subsequent abuse, respectively. The majority of abusers (36.0, 97.3%) reported a sense of pleasure or euphoria at the time of their propofol injection. Withdrawal symptoms occurred in five abusers (13.2%). Thirteen (36.1%) reported disruptions in their work life. None of the respondents had previously admitted to and or reported abuse of any other controlled substances.

CONCLUSIONS

These results provided reference data for the regulation of propofol in Korea as a controlled substance and may also be of interest to international agencies in other countries.

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.

Abuse potential assessment of propofol by its subjective effects after sedation

Objective: In this study, we examined the euphoric effect of propofol and its high satisfaction ratio regarding its liability to be abused, particularly in painless procedures, such as colonoscopy.

Methods: Fifty subjects aged between 18 and 65 years who fulfilled the criteria for ASA 1-2 and were prepared for colonoscopy were enrolled into this study. For intravenous sedation induction, 2 mg/kg propofol was used, and additional injections were administered according to BIS values. After colonoscopy, the subjects were taken to a recovery room and observed for 30 minutes. Patients were interviewed with the modified Brice questionnare regarding the incidence and the content of dreams. A 5-point Likert scale was used to classify their dreams, and the content of the dreams was also recorded. To assess the subjective effects of propofol, the patients were asked to use the Hall and Van der Castle emotion scale; their biological states were also assessed. The patients’ feelings regarding propofol were each rated as absent or present. We used the Morphine-Benzedrine Group scale to measure the euphoric effects of propofol. At the end of the study, subjects scored their satisfaction on a five-point scale.

Results: There were no statistically significant differences in sex age, weight, propofol dose, or satisfaction ratio (p>0.05) in the groups, although male patients received a higher dose of propofol and had higher satisfaction ratio. Patients reported no residual after-effects. The incidence of dreaming was 42%. There was no statistically significant difference in dreaming between the sexes, but male patients had a higher dreaming ratio. Dreamers received higher propofol doses and had a higher satisfaction ratio (p>0.05). All dreamers reported happy dreams regarding daily life, and their mean MBG score was 10.5. There was no correlation between MBG scores and propofol doses (r= -0.044, p= 0.761).

Conclusions: We conclude that propofol functions as a reward; that patients enjoy its acute effects; and that no residual after-effects should arise. We suggest that propofol may carry potential for abuse, and further abuse liability testing is indicated.

Prescribing patterns of the four most commonly used sedatives in endoscopic examination in Korea: propofol, midazolam, diazepam, and lorazepam

As the sedative use increases due to the effectiveness and relatively safe profile, the abuse potential is also increasing. This study was conducted to examine the usage of four sedative agents in endoscopic examination and to compare the propofol use with the other three sedatives. Using National Health Insurance claims data from 2008 to 2012, we identified the number of cases of conscious sedation during endoscopy using one or more of the following agents: propofol, midazolam, diazepam, and lorazepam. The general characteristics of patients and medical service providers were analyzed, and the regional and annual distributions of frequency of use were compared. We also identified patient cases with excessive number of endoscopic examinations. Among the total of 3,156,231 sedatives users, midazolam was the most commonly used agent (n=2,845,250, 90.1%). However, the largest increase in patient number, which increased from 11,410 in 2008 to 28,170 in 2012, was observed with propofol. While the majority of patients received an annual endoscopy, we identified several suspected abuse cases of patients receiving endoscopies repetitively as many as 114 times in five years. The rise of sedative use in endoscopic examinations and several patient cases of repeated sedative administration suggest a potential risk for abuse. Medical service providers should be cautious when using sedatives and carefully review each patient's medical history prior to the procedure.

Self-administration of propofol is mediated by dopamine D1 receptors in nucleus accumbens in rats

As a widely used intravenous short-acting anesthetic, propofol is recently indicated by clinical and animal studies for its abuse potential, but the mechanism underlying propofol abuse is largely unknown. This study examined the contribution of dopamine receptor subtype (D1 and D2 receptors) and neuroanatomical locus (i.e. nuclear accumbens) in the maintenance of propofol self-administration in rats. After the acquisition and maintenance of self-administration of propofol (1.7 mg/kg/infusion) under a fixed ratio (FR1) schedule of reinforcement over 14 days, rats were treated by either intraperitoneal injection or intra-nucleus accumbens (NAc) injection of D1 receptor antagonist (SCH23390) or D2 receptor antagonists (spiperone and eticlopride) 10 min prior to the subsequent propofol self-administration. We demonstrated (i) systemic administration of SCH23390 (10, 30, 100 μg/kg, i.p.) dose-dependently decreased the rate of propofol-maintained self-administration, suggesting a critical role of the D1 receptor in mediating propofol self-administration; (ii) the blockade of the propofol self-administration by SCH23390 was specific since spiperone and eticlopride did not affect propofol self-administration and SCH23390 at these doses did not affect food-maintained responding under an FR5 schedule; (iii) intra-accumbenal injection of SCH23390 (2.5 μg/site) but not eticopride (3.0 μg/site) attenuated the propofol self-administration, localizing nuclear accumbal D1 receptors as a critical locus in the reinforcement of propofol. Together, these findings provide the first direct evidence that D1 receptors in nuclear accumbens play an important role in the maintenance of propofol self-administration.

Propofol use for sedation or sedation for propofol use?

A large amount of pharmacological and clinical evidence supports the abuse potential of propofol. Although previous case reports have indicated that recreational use of propofol is primarily by medical professionals, its spread among the general public has recently been highlighted. This is the first case report to show that cravings for propofol can be quite intense in some people, and thus propofol can be wrongfully used by clinicians who are enticed by the promise of monetary gain. Illicit diversion of propofol in hospitals has been confirmed; thus, propofol has been designated as a controlled substance in South Korea as of February 2011.

The misuse and abuse of propofol

Media attention on the misuse of propofol increased significantly when the drug was implicated in the death of pop music superstar Michael Jackson in 2010. The misuse and abuse of propofol among healthcare providers has been reported worldwide, with some misuse resulting in death. Propofol policies guiding healthcare worker re-entry into the workplace after misusing propofol have received rare attention in the research literature. The paucity of information regarding propofol-specific re-entry policies suggests that little research has addressed this problem and the lack of research and policy guidance can contribute to unsafe re-entry and even death. This paper focuses on healthcare providers because they have an easy access to propofol and therefore are vulnerable to misusing or abusing the drug. To accomplish this, the pharmacology and misuse/abuse potential of propofol and the influence of the 12-step recovery paradigm in the re-entry literature are reviewed. In conclusion, existing research and policy are drawn upon to suggest employment re-entry guidelines for healthcare workers.

Clinical effects and lethal and forensic aspects of propofol

Propofol is a potent intravenous anesthetic agent that rapidly induces sedation and unconsciousness. The potential for propofol dependency, recreational use, and abuse has only recently been recognized, and several cases of accidental overdose and suicide have emerged. In addition, the first documented case of murder using propofol was reported a few months ago, and a high profile case of suspected homicide with propofol is currently under investigation. A number of analytical methods have been employed to detect and quantify propofol concentrations in biological specimens. The reported propofol-related deaths and postmortem blood and tissue levels are reviewed. Importantly, limitations of propofol detection are discussed, and future considerations are presented. Because propofol has the potential for diversion with lethal consequences, the forensic scientist must have a basic understanding of its clinical indications and uses, pharmacologic properties, and detection methods. In addition, medical institutions should develop systems to prevent and detect diversion of this potential drug of abuse.

Prescription opioid abuse and dependence among physicians: hypotheses and treatment

Physician impairment is a serious public health issue affecting physicians as well as their families, colleagues, and patients. Though physicians generally display healthier habits than members of the general population, overall rates of impairment are similar among both groups, and prescription drug abuse (including prescription opioids) is particularly problematic among physicians. The current review focuses mainly on prescription opioid abuse and dependence among physicians. It includes a brief history of early physician experiences with anesthetic and analgesic agents, and explores several hypotheses regarding the etiology of prescription opioid abuse and dependence among physicians. Barriers to identification and to treatment entry among physicians are discussed. In addition, methods of assessment and successful treatment in specialized impaired physician programs are described. Medical and psychosocial interventions, 12-step involvement, and extensive use of evaluations are highlighted. Attention is paid to typical follow-up contracting and monitoring strategies, as well as strategies for prevention. Given the extremely positive outcomes demonstrated by specialized programs for treating impaired professionals, it is recommended that their methods be disseminated and utilized in treatment centers for the general public.

Pharmacological and clinical evidences on the potential for abuse and dependence of propofol: a review of the literature

Propofol (2,6-diisopropylphenol) is an intravenous short-acting anaesthetic widely used for inducing and maintaining anaesthesia. Propofol is also being increasingly used for sedation. Beside medical use, propofol is abused for recreational purpose, mostly in medical professionals who are not informed of the risk of dependence to this compound. The aim of this review was to provide an overview of molecular, animal and clinical pharmacological data of the literature evidencing the potential for abuse and dependence of propofol.

A Survey of Propofol Abuse in Academic Anesthesia Programs

BACKGROUND

Although propofol has not traditionally been considered a drug of abuse, subanesthetic doses may have an abuse potential. We used this survey to assess prevalence and outcome of propofol abuse in academic anesthesiology programs.

METHODS

E-mail surveys were sent to the 126 academic anesthesiology training programs in the United States.

RESULTS

The survey response rate was 100%. One or more incidents of propofol abuse or diversion in the past 10 yr were reported by 18% of departments. The observed incidence of propofol abuse was 10 per 10,000 anesthesia providers per decade, a fivefold increase from previous surveys of propofol abuse (P = 0.005). Of the 25 reported individuals abusing propofol, 7 died as a result of the propofol abuse (28%), 6 of whom were residents. There was no established system to control or monitor propofol as is done with opioids at 71% of programs. There was an association between lack of control of propofol (e.g., pharmacy accounting) at the time of abuse and incidence of abuse at the program (P = 0.048).

CONCLUSIONS

Propofol abuse in academic anesthesiology likely has increased over the last 10 yr. Much of the mortality is in residents. Most programs have no pharmacy accounting or control of propofol stocks. This may be of concern, given that all programs reporting deaths from propofol abuse were centers in which there was no pharmacy accounting for the drug.

Lethal self administration of propofol (Diprivan). A case report and review of the literature

The death of a female anaesthesiologist is reported. Although the situation at the scene indicated propofol overdose-related death, self-administration of such high doses of propofol was unlikely, given the pharmacological properties of this drug. The analysis of the situation at the scene and the toxicological analysis in which the blood and liver propofol concentrations were 2.40microg/ml and 0.56microg/g, respectively, supported the conclusion that the death was a consequence of propofol self-administration at therapeutic doses from a person who used the drug on chronic basis seeking to its euphoric effects. However, because the toxic concentrations of propofol in non-intubated patients may be different from those intubated and fully supported in the operating room or in the intensive care unit, a mere interpretation of the blood and tissue concentrations of propofol in the toxicological analysis can confirm the drug intake but it may be of limited diagnostic significance without taking into account this difference.