Fentanyl is a potent synthetic opioid that has been shown to produce sleep disturbances, and the deterioration of sleep quality is associated with drug abuse and relapse in humans. The hypocretin/orexin neuropeptide system is a plausible pharmacological target, and dual-hypocretin antagonists such as lemborexant may mitigate sleep disturbances associated with fentanyl dependence. The current study characterizes sleep macroarchitecture (time spent asleep or awake) and microarchitecture (the number of bouts, and NREM sleep spindle characterization) prior to fentanyl vapor exposure (baseline), following one week of drug abstinence, and four weeks of drug abstinence in female and male rats. Females and males showed a reduction in the amount of time spent in rapid eye movement (REM) sleep following one week of abstinence. The pre-treatment of lemborexant the following day increased the amount of time spent in REM, compared to vehicle at both one and four weeks of abstinence. While there was no effect of fentanyl abstinence on the amount of time spent in non-rapid eye movement (NREM) sleep and wakefulness, lemborexant increased the amount time spent in NREM and decreased the amount of time spent awake. Examination of microarchitecture demonstrated a decrease in the number of NREM bouts at one week of abstinence, which lemborexant subsequently brought back to baseline levels at weeks one and four. Abstinence from fentanyl did not impact the number of NREM sleep spindles, but indicated a trend showing a decrease in intra-spindle frequency at one week of abstinence. Lemborexant, however, increased the number of spindles at weeks one and four of abstinence. Presently, findings indicate that fentanyl abstinence produces changes in sleep macroarchitecture, particularly REM sleep disruptions, which may be alleviated by lemborexant. This highlights the need for further examination of the relationship between sleep disturbances and drug abstinence, and the use of dual-hypocretin antagonists as therapeutic intervention.

Thesis (M.S.)--University of Michigan, 2006. / Includes bibliographical references (leaves 116-122).

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Os opióides de curta duração e de alta potencia analgésica, como o fentanil, embora amplamente utilizados em cães, ainda são pouco empregados pela via epidural nesta espécie. O presente estudo teve como objetivo avaliar a associação do anestésico local lidocaína à morfina ou à combinação morfina-fentanil, pela via epidural. Foram analisados os efeitos cardiovasculares, respiratórios bem como a analgesia pós-operatória, em cães submetidos a cirurgia de joelho. Para tanto, 24 animais da espécie canina foram aleatoriamente divididos em 2 grupos. Todos os animais receberam acepromazina (0,05 mg/kg), foram induzidos com propofol (5 mg/kg) e mantidos em anestesia inalatória. Os animais do GRUPO I foram tratados com lidocaína (5mg/kg) associada a morfina (0,1mg/kg) e os animais do GRUPO II receberam, pela via epidural, a combinação lidocaína-morfina-fentanil, sendo este último na dose de 2µ/kg. Parâmetros como frequência cardíaca, respiratória, pressão arterial (sistólica, média e diastólica) foram mensurados, bem como pH e gases sanguíneos. Para a avaliação da analgesia foram utilizadas a escala Analógica-visual (EAV), a escala proposta por Lascelles, 1994 e a termoalgimetria. Amostras de sangue foram coletadas para posterior dosagem de cortisol e Interleucina-06. O período de avaliação imediata foi de 06 horas após a cirurgia, sendo os animais reavaliados no período de 24 horas após o procedimento. No tocante aos parâmetros cardiorrespiratórios os grupos se comportaram de maneira muito semelhante. Entretanto, pode-se observar que os animais tratados com a combinação lidocaína-fentanil-morfina apresentaram menor escore de dor quando avaliados pelas escalas do estudo no período pós-operatório. De fato verificou-se diferença significativa nos escores da EAV (p <0,05) nos tempos T180 e T360; na escala de Lascelles obteve-se diferença estatística nos tempos T180, T360 e T24h e na termoalgimetria houve diferença estatística nos tempos T180, T360 e T24h. A analgesia de resgate foi necessária em 3 animais do Grupo II, enquanto no Grupo I a necessidade desta medicação foi observada em 6 animais. Pode-se concluir, com os resultados obtidos, que a associação do fentanil no protocolo de anestesia epidural, promoveu adequada analgesia perioperatória, além de produzir um efeito sinérgico-residual, o que melhorou a analgesia pós-operatória, diminuindo a necessidade de analgesia de resgate. / Short duration opioids and high potency analgesics such as fentanyl, although widely used in dogs are seldom used for epidural anesthesia in this species. This study aimed to evaluate the association of lidocaine with morphine or morphine-fentanyl combination, epidurally. 24 dogs were randomly divided into two groups. All animals received acepromazine intramuscularlly (0.05 mg / kg), were induced with propofol (5 mg / kg) and maintained under inhalation anesthesia. The animals in group I were treated with lidocaine (5 mg / kg) combined with morphine (0.1 mg / kg) epidurally and the animals of group II received epidurally, the combination lidocaine-morphine-fentanyl, the latter at the dose of 2µ/kg. Parameters such as heart and respiratory rate, blood pressure (systolic, mean and diastolic), blood gases and pH were measured. For the assessment of analgesia were used visual-analogue scale (VAS), the scale proposed by Lascelles and thermoalgimetry. Blood samples were collected for later determination of cortisol and interleukin-06. The evaluation period was 06 hours after surgery, the animals were re-evaluated within 24 hours after the procedure. Except the cardiorespiratory parameters, the groups were similarly. However, was observed that animals treated with the combination lidocaine-fentanyl-morphine had lower pain scores in the postoperative period. In fact there were significant differences in VAS scores (p <0.05) at times T180 and T360; in Lascelles scores at times T180, T360 and T24h and there were no statistical diferences in thermoalgimetry at times T180, T360 and T24h. The rescue analgesia was required in three animals in Group II, and six animals in Group I. It can be concluded that the combination of fentanyl in epidural anesthesia protocol, promoted adequate perioperative analgesia, producing synergistic and residual effects, which improved postoperative analgesia.

The Centers for Disease Control and Prevention deemed the increase in overdose fatalities, due to the use of opioids, an “opioid epidemic” in the United States. Heroin, fentanyl, and other synthetic opioids are commonly abused and are contributing to the opioid epidemic. In 2016, the Drug Enforcement Administration temporarily placed three fentanyl analogs (beta-hydroxythiofentanyl, butyryl fentanyl, and furanyl fentanyl) under Schedule I due to their imminent threat to public health. These drugs elicit analgesic effects similar to heroin making them desirable drugs to abuse. Novel fentanyl analogs and designer opioids are expected to become more prominent in forensic casework in the near future as the opioid epidemic continues. These drugs can be seen in forensic seized drug and urine casework samples either alone or mixed with other drugs of abuse. It is therefore necessary to have an efficient methodology to identify these new compounds. Currently, gas chromatography-mass spectrometry (GC/MS) is used to identify drugs of abuse and is considered the “gold standard” in forensic casework. However, analysis times can often range from 15 to 60 minutes in length. Another drawback is the need for spectral library matching, which requires analytical reference materials for identification. Therefore, the identification of novel fentanyl analogs and designer drugs is limited until a reference material becomes available. In this study, direct sample analysis time-of-flight mass spectrometry (DSA-TOFMS) was evaluated to provide rapid identification of fentanyl and other synthetic opioids in seized drug and urine casework samples. DSA is a direct ambient ionization source, which requires no chromatography and minimal sample preparation. TOFMS is a high resolution mass spectrometer that uses collision-induced dissociation (CID) to produce precursor ion and characteristic fragmentation ions, which provide additional structural and molecular formula information, allowing for the identification of compounds without a reference material. The analytes explored in this study include: heroin, 6-monoacetylmorphine (6-MAM), morphine, fentanyl, norfentanyl, 4-anilino-N-phenethylpiperidine (4-ANPP), acetyl fentanyl, beta-hydroxythiofentanyl, butyryl fentanyl, furanyl fentanyl, valeryl fentanyl, AH-7921, U-47700, buprenorphine, norbuprenorphine, desomorphine, MT-45, W-15, and W-18. Direct sample analysis time-of flight mass spectrometry (DSA-TOFMS) is a novel instrumentation that could be utilized in the forensic sciences field to qualitatively identify illicit substances in casework samples. In this study, 19 compounds of interest containing heroin, fentanyl, fentanyl analogs, and other synthetic opioids were evaluated using DSA-TOFMS. DSA-TOFMS abbreviated the workload of the analysis and was utilized to provide precursor ion and characteristic fragmentation ions within an analysis time of 20 seconds. Certified reference standards were used to optimize instrumentation settings, to determine precursor ions and characteristic fragmentation ions, and to determine the limit of detection of the instrument. A carryover study determined there were no persisting ions present when entering the capillary inlet between runs. A repeatability study revealed the DSA-TOFMS repeated results within the acceptable criteria range of above 500 counts and within 10ppm error 93% (10ppm) and 83% (1ppm). Forensic seized drug casework samples were evaluated with DSA-TOFMS and qualitatively identified. Out of the 64 samples, 89% were qualitatively identified as heroin, 4% were qualitatively identified as fentanyl, 1% was qualitatively identified as heroin and fentanyl, 3% were qualitatively identified as acetyl fentanyl, and 3% were qualitatively identified as furanyl fentanyl. The casework samples containing furanyl fentanyl were considered “true unknown unknown samples,” as the Maine Health and Environmental Testing Laboratory gas chromatography-mass spectrometry library did not have a spectrum to use for the identification of these samples. Forensic urine casework samples were evaluated with DSA-TOFMS. Samples previously confirmed to contain compounds of interest were prepared using minimal sample preparation technique (filtered using 0.45 microns syringe filters and diluted (1:10) with LC/MS grade water). Analysis displayed the limitations of DSA-TOFMS as only twelve of the forty compounds of interest were present and only three of the twelve were within the acceptable criteria range. DSA-TOFMS is a fast and reliable technique with minimal sample preparation for forensic seized drug samples. However, the concentration in complex matrixes, such as urine and blood, were unable to be qualitatively identified using this sample preparation method by DSA-TOFMS.

No description available.

The increase in heroin use is one factor contributing to the current opioid epidemic in the United States. There are three Food and Drug Administration (FDA) approved medications for the treatment of opioid use disorder (OUD), and these include agonist (i.e. methadone and buprenorphine) and antagonist (i.e. naltrexone) therapies. Although these medications are effective for some patients, regulatory constraints for agonist therapies limit access and patient compliance for naltrexone is poor. The development of new therapies, such as immunopharmacotherapies, for the treatment of OUD is a priority for the National Institute of Drug Abuse. A heroin immunopharmacotherapy, or vaccine, produces heroin selective antibodies that bind to and sequester heroin in the periphery. One formulation of a heroin-tetanus toxoid (TT) conjugate vaccine has shown promise in preclinical studies in mice in monkeys but has not been fully assessed to determine independent variables that might impact vaccine effectiveness such as heroin route of administration, species of animal or abuse-related behavioral endpoints. Chapter II of this dissertation aimed to determine effectiveness and selectivity of the heroin-TT conjugate vaccine to alter the antinociceptive effects of subcutaneous and intravenous heroin in male and female rats. In addition, maximal vaccine effects were compared to effects of a positive control naltrexone. Vaccine effectiveness to reduce heroin antinociception was selective, but effectiveness did not depend on route of administration. Furthermore, maximum effects were less than those seen with a clinically meaningful dose of naltrexone. Combining the vaccine with naltrexone enhanced the effectiveness of naltrexone to block the antinociceptive effects of heroin. Chapter III determined vaccine effectiveness and selectivity to block heroin’s discriminative-stimulus effects in nonhuman primates and compared maximal effects produced by vaccine and naltrexone. The heroin vaccine weakly but selectively reduced the abuse-related subjective-like effects of heroin in one of two monkeys. However, chronic naltrexone treatment nonselectively antagonized the abuse-related effects of both heroin and fentanyl, and naltrexone effects were more robust than those of the vaccine. Chapter IV established a translational procedure to assess candidate medication effects on the reinforcing effectiveness of heroin in a heroin versus food choice procedure in rats. In the procedure, rats choose between a liquid food reinforcer and ascending doses of heroin in a 5-component choice procedure. Heroin versus food choice was found to be sensitive to an environmental manipulation of altering response requirement for both reinforcers. Chronic buprenorphine decreased heroin choice, consistent with its FDA-approved indication for treating OUD. Collectively, these data suggest that the current formulation of the heroin-TT conjugate vaccine may not be as effective as naltrexone at decreasing heroin use. However, one potential indication the vaccine may be useful for is as an adjunctive therapy to clinically available agonist or antagonist medications and a heroin versus food choice procedure in rodents would be one way to full assess this preclinically.

Die orthotope Lebertransplantation (OLT) ist ein etabliertes Standardtherapieverfahren von Endzuständen verschiedenster Lebererkrankungen. Bei Patienten mit Lebererkrankungen kommt es zu einer deutlichen Reduktion der hepatischen Metabolisierung und Elimination von verschiedensten Medikamenten. Fentanyl ist das Opioid der Wahl im Rahmen der Anästhesie bei Patienten mit Lebererkrankungen. Die Pharmakokinetik von Fentanyl ist besonders in der anhepatischen Phase durch einen Ausfall der hepatischen Elimination gekennzeichnet, sodass es zu hohen Plasmakonzentrationen von Fentanyl kommen kann. Besonders bei der Fentanylinfusion bis zur Reperfusion kann dies zu einer verzögerten Extubation führen, welche im Rahmen des Fast-Track-Verfahrens vermieden werden sollte. Hauptanliegen unserer Studie ist der Vergleich zweier Infusionsregimes für das Opioid Fentanyl, nämlich der Beendigung der Fentanylapplikation mit Beginn der anhepatischen Phase (Studiengruppe) und zum Zeitpunkt der Reperfusion (Kontrollgruppe). Dazu wurden von 22 Patienten (Studiengruppe: n=10; Kontrollgruppe: n=12) intraoperativ zu neun definierten Messzeitpunkten (MZP) die Verläufe der arteriellen Fentanylplasmakonzentration, sowie von Parametern des Säure-Basen-Haushaltes und der hämodynamische Messwerte erfasst. Die Bestimmung der Fentanylkonzentration erfolgte mit Hilfe der Flüssigchromatographie mit Massenspektrometrie (SSQ 7000, Finnigan), der Säure-Basen-Haushalt mittels Blutgasanalyse (ABL 700, Radiometer Medical A/S, Kopenhagen). Hinsichtlich der Daten für MELD-Score, Diagnose und Gesamtoperationsdauer unterschieden sich die beiden Gruppen nicht signifikant voneinander. Im Verlauf der anhepatischen Phase lag die Fentanylkonzentration im Plasma in der Kontrollgruppe signifikant höher als in der Studiengruppe. Die gefundenen höheren Fentanylspiegel in der Kontrollgruppe sind Ausdruck einer nicht vorhandenen hepatischen Fentanylclearance in der anhepatischen Phase. Basierend auf unseren Daten wollen wir zu einer Überprüfung des Infusionskonzeptes von Fentanyl bei OLT anregen. Während einer OLT sollte im Hinblick auf das Fast-Track-Konzept über eine Beendigung der Fentanylzufuhr zum Beginn der anhepatischen Phase nachgedacht werden.

Thesis (doctoral)--Freie Universität, Berlin, 2000.

The objectives of this study were to determine the cardiopulmonary effects and pharmacokinetics of fentanyl in dogs during isoflurane anesthesia and during anesthetic recovery with or without dexmedetomidine or acepromazine sedation. This was investigated in 7 healthy dogs using a randomized cross over study design. Dogs were given fentanyl as an initial IV loading dose (5 μg/kg) followed by an infusion (5 μg/kg/hr) for 120 minutes during isoflurane anesthesia and for 60 minutes following isoflurane discontinuation. Dogs received IV dexmedetomidine (2.5 μg/kg), acepromazine (0.05 mg/kg) or saline at the time of isoflurane discontinuation. Cardiopulmonary variables were measured and blood samples were obtained at multiple time points during the anesthetic maintenance and recovery phases. Plasma concentrations of fentanyl were measured using HPLC-MS, and subsequent population pharmacokinetic analysis was performed. During isoflurane anesthesia, fentanyl bolus administration resulted in significant changes in measured cardiopulmonary variables, however, many returned to baseline values during the maintenance of anesthesia. During anesthetic recovery, dexmedetomidine administration resulted in significant increases in PaCO2, and decreases in PvO2 and CI. Systemic arterial blood pressures were significantly lower in dogs receiving acepromazine, however CI and PvO2 were significantly higher compared to the other treatments. Analysis of fentanyl plasma concentrations showed that fentanyl pharmacokinetics best fit a 2-compartmental model, with average concentrations in the treatment groups ranging from 1.6 to 4.5 ng/mL during isoflurane anesthesia, and from 1.6 to 2.0 ng/mL during anesthetic recovery. Plasma concentrations of fentanyl were significantly higher with dexmedetomidine administration compared to the other treatments during the recovery period. Compared to the maintenance phase of anesthesia, anesthetic recovery with dexmedetomidine administration did not significantly change fentanyl pharmacokinetics, while acepromazine administration increased systemic and intercompartmental clearance, and recovery without sedation increased the central volume of distribution and systemic clearance. In conclusion, recovery from anesthesia with concurrent fentanyl administration, with or without sedation, caused clinically significant alterations in cardiopulmonary function that influenced fentanyl disposition in healthy dogs. / Ontario Veterinary College Pet Trust Fund