A benzodiazepine, diazepam, has been the leading antidote for seizures caused by nerve agents, the most toxic chemical weapons of mass destruction, since the 1960s. However, its limitations have often brought questions about its usefulness. Extensive effort has been devoted into exploring alternatives, such as other benzodiazepines, anticholinergics, or glutamate antagonists. However, only few showed clear clinical benefit. The only two options to ultimately reach clinical milestones are Avizafone, a water-soluble prodrug of diazepam adopted by the French and UK armed forces, and intramuscular midazolam, adopted by the US Army. The recently FDA-approved new intramuscular application of midazolam brought several advantages, such as rapid onset of action, short duration with predictable pharmacokinetics, increased water solubility for aqueous injectable solutions, and prolonged storage stability. Herein, we discuss the pitfalls and prospects of using midazolam as a substitute in anticonvulsant therapy with a particular focus on military purposes in combat casualty care. We have also considered and discussed several other alternatives that are currently at the experimental level. Recent studies have shown the superiority of midazolam over other benzodiazepines in the medical management of poisoned casualties. While its use in emergency care is straightforward, the proper dose for soldiers under battlefield conditions is questionable due to its sedative effects.
- MeSH
- antikonvulziva * aplikace a dávkování terapeutické užití MeSH
- diazepam * aplikace a dávkování MeSH
- lidé MeSH
- midazolam * aplikace a dávkování MeSH
- nervová bojová látka * MeSH
- záchvaty * farmakoterapie chemicky indukované MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- Názvy látek
- antikonvulziva * MeSH
- diazepam * MeSH
- midazolam * MeSH
- nervová bojová látka * MeSH
BACKGROUND AND PURPOSE: Opioids and benzodiazepines are frequently combined in medical as well as in non-medical contexts. At high doses, such combinations often result in serious health complications attributed to pharmacodynamics interactions. Here, we investigate the contribution of the metabolic interactions between oxycodone, diazepam and diclazepam (a designer benzodiazepine) in abuse/overdose conditions through ex vivo, in vivo and in silico approaches. EXPERIMENTAL APPROACH: A preparation of pooled human liver microsomes was used to study oxycodone metabolism in the presence or absence of diazepam or diclazepam. In mice, diazepam or diclazepam was concomitantly administered with oxycodone to mimic acute intoxication. Diclazepam was introduced on Day 10 in mice continuously infused with oxycodone for 15 days to mimic chronic intoxication. In silico modelling was used to study the molecular interactions of the three drugs with CYP3A4 and 2D6. KEY RESULTS: In mice, in acute conditions, both diazepam and diclazepam inhibited the metabolism of oxycodone. In chronic conditions and at pharmacologically equivalent doses, diclazepam drastically enhanced the production of oxymorphone. In silico, the affinity of benzodiazepines was higher than oxycodone for CYP3A4, inhibiting oxycodone metabolism through CYP3A4. Oxycodone metabolism is likely to be diverted towards CYP2D6. CONCLUSION AND IMPLICATIONS: Acute doses of diazepam or diclazepam result in the accumulation of oxycodone, whereas chronic administration induces the accumulation of oxymorphone, the toxic metabolite. This suggests that overdoses of opioids in the presence of benzodiazepines are partly due to metabolic interactions, which in turn explain the patterns of toxicity dependent on usage. LINKED ARTICLES: This article is part of a themed issue on Advances in Opioid Pharmacology at the Time of the Opioid Epidemic. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v180.7/issuetoc.
- Klíčová slova
- benzodiazepines, designer benzodiazepines, diazepam, diclazepam, metabolic interactions, opioids, oxycodone,
- MeSH
- benzodiazepiny toxicita MeSH
- cytochrom P-450 CYP3A MeSH
- diazepam farmakologie MeSH
- lidé MeSH
- modely u zvířat MeSH
- myši MeSH
- opioidní analgetika toxicita MeSH
- oxykodon * MeSH
- oxymorfon MeSH
- předávkování léky * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- benzodiazepiny MeSH
- cytochrom P-450 CYP3A MeSH
- diazepam MeSH
- opioidní analgetika MeSH
- oxykodon * MeSH
- oxymorfon MeSH
BACKGROUND: Neurosteroids are investigated as effective antidotes for the poisoning induced by tetramethylenedisulfotetramine (TMDT) as well as treatments for epileptic spasms during infancy. Both these conditions are quite resistant to pharmacotherapy; thus, a search for new treatments is warranted. METHODS: In this study, we determined the efficacy of two novel neurosteroids, pregnanolone glutamate (PAG) and pregnanolone pyroglutamate (PPG), and tested these drugs in doses of 1-10 mg/kg (ip) against the TMDT syndrome and in our rodent model of infantile spasms. RESULTS: Only PPG in doses 5 and 10 mg/kg suppressed the severity of the TMDT syndrome and TMDT-induced lethality, while the 1 mg/kg dose was without an effect. Interestingly, the 1 mg/kg dose of PPG in combination with 1 mg/kg of diazepam was also effective against TMDT poisoning. Neither PAG nor PPG were effective against experimental spasms in the N-methyl-D-aspartate (NMDA)-triggered model of infantile spasms. CONCLUSIONS: While evidence suggests that PAG can act through multiple actions which include allosteric inhibition of NMDA-induced and glycine receptor-evoked currents as well as augmentation of ɣ-aminobutyric acid subtype A (GABAA) receptor-induced currents, the agent appears to neither have the appropriate mechanistic signature for activity in the infantile spasm model, nor the adequate potency, relative to PPG, for ameliorating the TMDT syndrome. The full mechanisms of action of PPG, which may become a potent TMDT antidote either alone or in combination with diazepam are yet unknown and thus require further investigation.
- Klíčová slova
- Antidote, Neurosteroids, Neurotoxicity, Severe seizures, Tetramethylenedisulfotetramine,
- MeSH
- diazepam farmakologie MeSH
- hlodavci MeSH
- křeče u dětí * chemicky indukované farmakoterapie MeSH
- kyselina glutamová MeSH
- kyselina pyrrolidonkarboxylová MeSH
- N-methylaspartát toxicita terapeutické užití MeSH
- neurosteroidy * MeSH
- neurotoxické syndromy * MeSH
- pregnanolon škodlivé účinky MeSH
- spasmus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- diazepam MeSH
- kyselina glutamová MeSH
- kyselina pyrrolidonkarboxylová MeSH
- N-methylaspartát MeSH
- neurosteroidy * MeSH
- pregnanolon MeSH
- tetramethylenedisulfotetramine MeSH Prohlížeč
Prolactin-releasing peptide (PrRP) has been proposed to mediate the central satiating effects of cholecystokinin (CCK) through the vagal CCK1 receptor. PrRP acts as an endogenous ligand of G protein-coupled receptor 10 (GPR10), which is expressed at the highest levels in brain areas related to food intake regulation, e.g., the paraventricular hypothalamic nucleus (PVN) and nucleus of the solitary tract (NTS). The NTS and PVN are also significantly activated after peripheral CCK administration. The aim of this study was to determine whether the endogenous PrRP neuronal system in the brain is involved in the central anorexigenic effect of the peripherally administered CCK agonist JMV236 or the CCK1 antagonist devazepide and whether the CCK system is involved in the central anorexigenic effect of the peripherally applied lipidized PrRP analog palm-PrRP31 in fasted lean mice. The effect of devazepide and JMV236 on the anorexigenic effects of palm-PrRP31 as well as devazepide combined with JMV236 and palm-PrRP31 on food intake and Fos cell activation in the PVN and caudal NTS was examined. Our results suggest that the anorexigenic effect of JMV236 is accompanied by activation of PrRP neurons of the NTS in a CCK1 receptor-dependent manner. Moreover, while the anorexigenic effect of palm-PrRP31 was not affected by JMV236, it was partially attenuated by devazepide in fasted mice. The present findings indicate that the exogenously influenced CCK system may be involved in the central anorexigenic effect of peripherally applied palm-PrRP31, which possibly indicates some interaction between the CCK and PrRP neuronal systems.
- MeSH
- anorektika aplikace a dávkování MeSH
- antagonisté hormonů aplikace a dávkování MeSH
- chemokiny CC účinky léků metabolismus MeSH
- cholecystokinin metabolismus MeSH
- devazepid aplikace a dávkování MeSH
- hormon uvolňující prolaktin aplikace a dávkování analogy a deriváty MeSH
- injekce intraperitoneální MeSH
- injekce subkutánní MeSH
- myši inbrední C57BL MeSH
- myši MeSH
- nucleus paraventricularis hypothalami účinky léků metabolismus MeSH
- nucleus solitarius účinky léků metabolismus MeSH
- omezení příjmu potravy MeSH
- peptidové fragmenty aplikace a dávkování MeSH
- přijímání potravy účinky léků MeSH
- protoonkogenní proteiny c-fos metabolismus MeSH
- signální transdukce MeSH
- sinkalid aplikace a dávkování analogy a deriváty MeSH
- stravovací zvyklosti účinky léků MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- anorektika MeSH
- antagonisté hormonů MeSH
- Ccl28 protein, mouse MeSH Prohlížeč
- chemokiny CC MeSH
- cholecystokinin MeSH
- devazepid MeSH
- Fos protein, mouse MeSH Prohlížeč
- hormon uvolňující prolaktin MeSH
- JMV 236 MeSH Prohlížeč
- palm11-PrRP31 MeSH Prohlížeč
- peptidové fragmenty MeSH
- protoonkogenní proteiny c-fos MeSH
- sinkalid MeSH
It is generally expected that biotransformation and excretion of pharmaceuticals occurs similarly in fish and mammals, despite significant physiological differences. Here, we exposed European perch (Perca fluviatilis) to the benzodiazepine drug temazepam at a nominal concentration of 2 µg L-1 for 10 days. We collected samples of blood plasma, muscle, and brain in a time-dependent manner to assess its bioconcentration, biotransformation, and elimination over another 10 days of depuration in clean water. We observed rapid pharmacokinetics of temazepam during both the exposure and depuration periods. The steady state was reached within 24 h of exposure in most individuals, as was complete elimination of temazepam from tissues during depuration. Further, the biologically active metabolite oxazepam was produced via fish biotransformation, and accumulated significantly throughout the exposure period. In contrast to human patients, where a negligible amount of oxazepam is created by temazepam biotransformation, we observed a continuous increase of oxazepam concentrations in all fish tissues throughout exposure. Indeed, oxazepam accumulated more than its parent compound, did not reach a steady state during the exposure period, and was not completely eliminated even after 10 days of depuration, highlighting the importance of considering environmental hazards posed by pharmaceutical metabolites.
- Klíčová slova
- Accumulation, Depuration, Fish, Metabolic transformation, Metabolite, Pharmaceutical, Psychoactive drug,
- MeSH
- biotransformace MeSH
- chemické látky znečišťující vodu metabolismus toxicita MeSH
- hypnotika a sedativa metabolismus toxicita MeSH
- okounovití metabolismus fyziologie MeSH
- oxazepam metabolismus MeSH
- temazepam metabolismus toxicita MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- chemické látky znečišťující vodu MeSH
- hypnotika a sedativa MeSH
- oxazepam MeSH
- temazepam MeSH
The constitutive androstane receptor (CAR) is the essential regulator of genes involved both in xenobiotic and endobiotic metabolism. Diazepam has been shown as a potent stimulator of CAR nuclear translocation and is assumed as an indirect CAR activator not interacting with the CAR cavity. In this study, we sought to determine if diazepam is a ligand directly interacting with the CAR ligand binding domain (LBD) and if it regulates its target genes in a therapeutically relevant concentration. We used different CAR constructs in translocation and luciferase reporter assays, recombinant CAR-LBD in a TR-FRET assay, and target genes induction studied in primary human hepatocytes (PHHs), HepaRG cells, and in CAR humanized mice. We also used in silico docking and CAR-LBD mutants to characterize the interaction of diazepam and its metabolites with the CAR cavity. Diazepam and its metabolites such as nordazepam, temazepam, and oxazepam are activators of CAR+Ala in translocation and two-hybrid assays and fit the CAR cavity in docking experiments. In gene reporter assays with CAR3 and in the TR-FRET assay, only diazepam significantly interacts with CAR-LBD. Diazepam also promotes up-regulation of CYP2B6 in PHHs and in HepaRG cells. However, in humanized CAR mice, diazepam significantly induces neither CYP2B6 nor Cyp2b10 genes nor does it regulate critical genes involved in glucose and lipids metabolism and liver proliferation. Thus, we demonstrate that diazepam interacts with human CAR-LBD as a weak ligand, but it does not significantly affect expression of tested CAR target genes in CAR humanized mice.
- Klíčová slova
- CAR, NR1I3, cytochrome P450, diazepam, drug interaction, gene regulation,
- MeSH
- buněčné linie MeSH
- diazepam farmakologie MeSH
- dospělí MeSH
- hepatocyty účinky léků MeSH
- játra účinky léků MeSH
- konstitutivní androstanový receptor MeSH
- lidé středního věku MeSH
- lidé MeSH
- ligandy MeSH
- myši MeSH
- proliferace buněk účinky léků MeSH
- proteinové domény účinky léků MeSH
- receptory cytoplazmatické a nukleární metabolismus MeSH
- reportérové geny účinky léků genetika MeSH
- transport proteinů účinky léků MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- diazepam MeSH
- konstitutivní androstanový receptor MeSH
- ligandy MeSH
- NR1I3 protein, human MeSH Prohlížeč
- Nr1i3 protein, mouse MeSH Prohlížeč
- receptory cytoplazmatické a nukleární MeSH
Benzodiazepines (BZDs) are widely used in patients of all ages. Unlike adults, neonatal animals treated with BZDs exhibit a variety of behavioral deficits later in life; however, the mechanisms underlying these deficits are poorly understood. This study aims to examine whether administration of clonazepam (CZP; 1 mg/kg/day) in 7-11-day-old rats affects Gama aminobutyric acid (GABA)ergic receptors in both the short and long terms. Using RT-PCR and quantitative autoradiography, we examined the expression of the selected GABAA receptor subunits (α1, α2, α4, γ2, and δ) and the GABAB B2 subunit, and GABAA, benzodiazepine, and GABAB receptor binding 48 h, 1 week, and 2 months after treatment discontinuation. Within one week after CZP cessation, the expression of the α2 subunit was upregulated, whereas that of the δ subunit was downregulated in both the hippocampus and cortex. In the hippocampus, the α4 subunit was downregulated after the 2-month interval. Changes in receptor binding were highly dependent on the receptor type, the interval after treatment cessation, and the brain structure. GABAA receptor binding was increased in almost all of the brain structures after the 48-h interval. BZD-binding was decreased in many brain structures involved in the neuronal networks associated with emotional behavior, anxiety, and cognitive functions after the 2-month interval. Binding of the GABAB receptors changed depending on the interval and brain structure. Overall, the described changes may affect both synaptic development and functioning and may potentially cause behavioral impairment.
- Klíčová slova
- GABAA/BZD receptor binding, GABAB receptor binding, clonazepam, neonatal rat, subunit mRNA expression,
- MeSH
- benzodiazepiny farmakologie MeSH
- GABA metabolismus MeSH
- hipokampus účinky léků metabolismus MeSH
- klonazepam farmakologie MeSH
- krysa rodu Rattus MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- mozek účinky léků metabolismus MeSH
- novorozená zvířata MeSH
- potkani inbrední WF MeSH
- receptory GABA-A metabolismus MeSH
- receptory GABA-B metabolismus MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- benzodiazepiny MeSH
- GABA MeSH
- klonazepam MeSH
- receptory GABA-A MeSH
- receptory GABA-B MeSH
Pollution by psychoactive pharmaceuticals has been found to disrupt anti-predator behaviors of wild fish. The challenge is now to identify which of the many psychoactive drugs pose the greatest threat. One strategy is to screen for behavioral effects of selected pharmaceuticals using a single, widely available fish species such as zebrafish. Here, we show that although such high-throughput behavioral screening might facilitate comparisons between pharmaceuticals, the choice of strain is essential. While wild-caught zebrafish exposed to concentrations of the anxiolytic drug oxazepam as low as 0.57 μg L-1 showed a reduction in the response to conspecific alarm pheromone, laboratory strain AB did not respond to the alarm cue, and consequently, the anxiolytic effect of oxazepam could not be measured. Adaptation to the laboratory environment may have rendered laboratory strains unfit for use in some ecotoxicological and pharmacological studies, since the results might not translate to wild fish populations.
- Klíčová slova
- Benzodiazepines, Domestication, GABA, Oxazepam, Pharmaceutical pollution, Schreckstoff,
- MeSH
- anxiolytika MeSH
- benzodiazepiny MeSH
- chemické látky znečišťující vodu MeSH
- dánio pruhované * MeSH
- oxazepam MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- anxiolytika MeSH
- benzodiazepiny MeSH
- chemické látky znečišťující vodu MeSH
- oxazepam MeSH
Environmental concentrations of the anxiolytic drug oxazepam have been found to disrupt antipredator behaviors of wild fish. Most experiments exposed fish for a week, while evidence from mammals suggests that chronic exposure to therapeutic concentrations of benzodiazepines (such as oxazepam) results in the development of tolerance to the anxiolytic effects. If tolerance can also develop in response to the low concentrations found in the aquatic environment, it could mitigate the negative effects of oxazepam pollution. In the current study, we exposed wild-caught zebrafish to oxazepam (∼7 μg L-1) for 7 or 28 days and evaluated behavioral and physiological parameters at both time points. Females showed reduced diving responses to conspecific alarm pheromone after 7 days, but not after 28 days, indicating that they had developed tolerance to the anxiolytic effects of the drug. Zebrafish males were not affected by this oxazepam concentration, in line with earlier results. Serotonin turnover (ratio 5-HIAA/5-HT) was reduced in exposed females and males after 28 days, indicating that brain neurochemistry had not normalized. Post-confinement cortisol concentrations and gene expression of corticotropin-releasing hormone (CRH) were not affected by oxazepam. We did not find evidence that chronically exposed fish had altered relative expression of GABAA receptor subunits, suggesting that some other still unknown mechanism caused the developed tolerance.
- MeSH
- anxiolytika * MeSH
- chemické látky znečišťující vodu * MeSH
- dánio pruhované MeSH
- oxazepam MeSH
- znečištění životního prostředí MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- anxiolytika * MeSH
- chemické látky znečišťující vodu * MeSH
- oxazepam MeSH
We studied the adverse effects of four benzodiazepines frequently measured in European surface waters. We evaluated bioaccumulation potential of oxazepam, bromazepam, temazepam, and clobazam in freshwater fish species - perch (Perca fluviatilis) and we conducted a series of behavioral trials to assess their potential to alter boldness, activity, and social behavior. All selected endpoints were studied individually for each target benzodiazepine and as a mixture of all tested compounds to assess possible combinatory effects. We used a three-dimensional automated tracking system to quantify the fish behavior. The four compounds bioconcentrated differently in fish muscle (temazepam > clobazam > oxazepam > bromazepam) at high exposure (9.1, 6.9, 5.7, 8.1 µg L-1, respectively) and low exposure (0.5, 0.5, 0.3, 0.4 µg L-1, respectively) concentrations. A significant amount of oxazepam was also measured in fish exposed to temazepam, most likely because of the metabolic transformation of temazepam within the fish. Bromazepam, temazepam, and clobazam significantly affected fish behavior at high concentration, while no statistically significant changes were registered for oxazepam. The studied benzodiazepines affected behavior in combination, because the mixture treatment significantly changed several important behavioral traits even at low concentration, while no single compound exposure had such an effect at that dose. Based on our results, we conclude that effects of pharmaceuticals on aquatic environments could be underestimated if risk assessments only rely on the evaluation of single compounds. More studies focused on the combinatory effects of environmentally relevant mixtures of pharmaceuticals are necessary to fill the gaps in this knowledge.
- MeSH
- benzodiazepiny metabolismus toxicita MeSH
- chemické látky znečišťující vodu metabolismus toxicita MeSH
- chování zvířat účinky léků MeSH
- oxazepam metabolismus toxicita MeSH
- ryby metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- benzodiazepiny MeSH
- chemické látky znečišťující vodu MeSH
- oxazepam MeSH