-
Xenobiotica; the Fate of Foreign... Dec 2021Pirfenidone is a first-line drug for the treatment of idiopathic pulmonary fibrosis. The primary metabolic pathways of pirfenidone in humans are 5-hydroxylation and...
Pirfenidone is a first-line drug for the treatment of idiopathic pulmonary fibrosis. The primary metabolic pathways of pirfenidone in humans are 5-hydroxylation and subsequent oxidation to 5-carboxylpirfenidone. The aims of this study were to determine the cytochrome P450 isoforms responsible for pirfenidone 5-hydroxylation and to evaluate their contributions in human liver microsomes (HLM).Among the recombinant P450 isoforms, CYP1A2, CYP2D6, CYP2C19, CYP2A6, and CYP2B6 were shown to catalyse the 5-hydroxylation of pirfenidone. Pirfenidone 5-hydroxylase activity by HLM was inhibited by α-naphthoflavone (by 45%), 8-methoxypsolaren (by 84%), tranylcypromine (by 53%), and quinidine (by 15%), which are CYP1A2, CYP1A2/CYP2A6/CYP2C19, CYP2A6/CYP2C19, and CYP2D6 inhibitors, respectively.In 17 individual HLM donors, pirfenidone 5-hydroxylase activity was significantly correlated with phenacetin -deethylase ( = 0.89, < 0.001) and -mephenytoin 4'-hydroxylase activities ( = 0.51, < 0.05), which are CYP1A2 and CYP2C19 marker activities, respectively.By using the relative activity factors, the contributions of CYP1A2, CYP2C19, and CYP2D6 to pirfenidone 5-hydroxylation in the human liver were 72.8%, 11.8%, and 8.9%, respectively.In conclusion, we clearly demonstrated the predominant P450 involved in pirfenidone 5-hydroxylation in the human liver is CYP1A2, with CYP2C19 and CYP2D6 playing a minor role.
Topics: Catalysis; Cytochrome P-450 CYP1A2; Cytochrome P-450 CYP2C19; Cytochrome P-450 CYP2D6; Cytochromes; Humans; Hydroxylation; Liver; Microsomes, Liver; Pyridones
PubMed: 34779706
DOI: 10.1080/00498254.2021.2007553 -
Forensic Science International Dec 2021Cocaine-related emergency department admissions are increasing, and cocaine seizures are at an all-time high in Europe. Our aim was to investigate the trends in purity...
Cocaine-related emergency department admissions are increasing, and cocaine seizures are at an all-time high in Europe. Our aim was to investigate the trends in purity and adulterants over time in cocaine available to cocaine users at street level in Denmark. We used a representative sample of cocaine seized at street level and analyzed by the national departments of forensic medicine between 2006 and 2019 (n = 1460). Latent profile analysis was used to classify the samples based on cocaine, levamisole, and phenacetin content. Low purity cocaine comprised most of the cocaine seizures in early years, but its share began to decline in 2013, and from 2016 to 2019, the high purity profile was dominant. While the total number of samples containing adulterants decreased, levamisole remained a common and dangerous adulterant. The findings underline the need to inform the public, medical doctors, and service providers for people with drug use disorders about the higher potency of street cocaine.
Topics: Cocaine; Denmark; Drug Contamination; Humans; Levamisole; Seizures
PubMed: 34736046
DOI: 10.1016/j.forsciint.2021.111050 -
Journal of Analytical Toxicology Jul 2022Toxic adulterants are drug or chemical agents used to add bulk volume to traditional drugs of abuse such as cocaine and heroin. These cutting agents include levamisole,...
Toxic adulterants are drug or chemical agents used to add bulk volume to traditional drugs of abuse such as cocaine and heroin. These cutting agents include levamisole, metamizole, noxiptillin, phenacetin and xylazine as well as common legal drugs such as acetaminophen, caffeine, diphenhydramine, lidocaine, quinine, quetiapine and tramadol. Because they possess pharmacological activity they result in exposure of the user, but also in the case of pregnant women, the developing fetus, to potential drug toxicity. We describe the development, validation and implementation of a rapid (48 second sample-to-sample) test based on a qualitative data-dependent liquid chromatography-quadrupole time of flight mass spectrometry method for the analysis of toxic adulterating substances in umbilical cord tissue (UCT) samples. The method provides a means of studying potential in utero exposure to these agents. Library spectra comparison at three different collision energies was used in conjunction with retention time and accurate mass to identify these substances in UCT. Analytically based reporting limits were established to determine positivity rates of adulterants in UCT utilizing a standard addition approach. The method was applied to authentic cocaine and opioid positive UCT to screen for toxic adulterants. There were a total of 82 potential adulterant positives found in a 30-sample cohort of authentic UCT samples, with an average of 2.7 substances per case. Lidocaine was the predominant finding followed by caffeine, and diphenhydramine all of which could result from non-illicit drug exposure, however, there were positives for levamisole, phenacetin, noxiptillin and xylazine none of which are approved in the United States for human therapeutic use. This initial set of data established a preliminary positivity rate of potentially toxic adulterants in UCT samples positive for cocaine or opioid use.
Topics: Analgesics, Opioid; Caffeine; Cocaine; Diphenhydramine; Drug Contamination; Female; Humans; Levamisole; Lidocaine; Phenacetin; Pregnancy; Umbilical Cord; Xylazine
PubMed: 34592760
DOI: 10.1093/jat/bkab094 -
The Analyst Oct 2021We have developed a sensitive and rapid gold nanoparticle-based immunochromatographic strip (GNP-ICS) for the detection of phenacetin (PNCT) and paracetamol (PAP) using...
We have developed a sensitive and rapid gold nanoparticle-based immunochromatographic strip (GNP-ICS) for the detection of phenacetin (PNCT) and paracetamol (PAP) using an anti-PNCT monoclonal antibody (mAb). The sensitive anti-PNCT mAb (2D6) had a half maximal inhibitory concentration (IC) and limit of detection (LOD) of 3.51 and 0.21 ng mL, respectively. Additionally, its cross-reactivity with PAP was approximately 10.1%. The developed GNP-ICS assay based on GNP-labeled mAb was sensitive for the detection of PNCT with vLOD and cut-off values of 2.5 and 50 ng mL respectively and a vLOD value of 25 ng mL for PAP. Furthermore, the developed ELISA and GNP-ICS assays were applied to determine PNCT-spiked beverage samples without pretreatment, in addition to a kind of PAP-containing drug. The recoveries were validated using high performance liquid chromatography (HPLC). The results revealed that the developed GNP-ICS assay was reliable for the detection of PNCT in practical samples.
Topics: Acetaminophen; Chromatography, Affinity; Enzyme-Linked Immunosorbent Assay; Gold; Limit of Detection; Metal Nanoparticles; Phenacetin
PubMed: 34528034
DOI: 10.1039/d1an01173a -
The Science of the Total Environment Jan 2022Phenacetin (PNCT), a common antipyretic and analgesic drug, is often used to treat fever and headache. However, the effect of PNCT on nitrifiers in wastewater treatment...
Phenacetin (PNCT), a common antipyretic and analgesic drug, is often used to treat fever and headache. However, the effect of PNCT on nitrifiers in wastewater treatment processes remains unclear. The practicability of attaining partial nitrification (PN) through inhibitor-PNCT was investigated in this study. The optimal treatment conditions of soaking once for 18 h with 2.50 × 10 g PNCT/(g MLSS) were applied to the PN stability experiment. The results showed that ammonia oxidation activity recovered quickly after 3 cycles of operation, while nitrite oxidation activity was suppressed steadily. In addition, average ammonium removal efficiency and nitrite accumulation ratio during 138 cycles could reach 94.94% and 85.38%, respectively. Complimentary DNA high-throughput sequencing and oligotyping analysis showed that the activity of Nitrosomonas would gradually surpass Nitrospira after PNCT treatment only once. The decrease of Nitrospira activity was accompanied by the simplification of oligotypes after PNCT treatment, while Nitrosomonas could adapt to PNCT stress by reducing the differences between oligotypes. Metagenomics revealed that the decrease in the number of NXR in the nitrogen metabolism pathways was the key reason for achieving PN. The potential mechanisms might be that the dominant nitrite-oxidizing bacteria and complete ammonia oxidizers were bio-killed by PNCT.
Topics: Ammonia; Bioreactors; Metagenomics; Nitrification; Nitrites; Nitrogen; Oxidation-Reduction; Phenacetin
PubMed: 34525735
DOI: 10.1016/j.scitotenv.2021.150068 -
Drug Design, Development and Therapy 2021Avitinib is the first third-generation epithelial growth factor receptor (EGFR) inhibitor independently developed in China and is mainly used for treating non-small cell...
PURPOSE
Avitinib is the first third-generation epithelial growth factor receptor (EGFR) inhibitor independently developed in China and is mainly used for treating non-small cell lung cancer. However, pharmacokinetic details are limited. This study explored the in vivo and in vitro effects of avitinib on cytochrome CYP450 enzymes metabolic activity.
METHODS
A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determining six probe substrates and their metabolites. Avitinib influence on activity levels of CYP isozymes was examined in vitro using human and rat liver microsomes (HLMs/RLMs). For in vivo studies, rats were pretreated with 30 mg/kg avitinib once daily for 7 days (avitinib multiple-doses group), 30 mg/kg avitinib on day 7 (avitinib single-dose group), or an equivalent amount of CMC-Na once daily for 7 days (control group), followed by intragastrical administration of the probe substrates (1 mg/kg tolbutamide and 10 mg/kg phenacetin, bupropion, chlorzoxazone, dextromethorphan, and midazolam). Plasma pharmacokinetics and IC values of the probe substrates were then compared. Pharmacokinetic parameters were determined using non-compartmental analysis implemented in a pharmacokinetic program.
RESULTS
In vitro experiments revealed different inhibitory effects of avitinib on the six probe substrates with various IC values (bupropion, 6.39/22.64 μM; phenacetin, 15.79/48.36 μM; chlorzoxazone, 23.15/57.09 μM; midazolam, 27.64/59.6 μM; tolbutamide, 42.18/6.91 μM; dextromethorphan, 44.39/56.57 μM, in RLMs and HLMs respectively). In vivo analysis revealed significant differences ( <0.05) in distinct pharmacokinetic parameters (AUC, AUC , C, MRT, MRT , and CLz/F) for the six probe substrates after avitinib pretreatment.
CONCLUSION
A sensitive and reliable UPLC-MS/MS method was established to determine the concentration of six probe substrates in rat plasma. Avitinib had inhibitory effects on CYP450 enzymes, especially cyp2b1, cyp1a2 in RLMs, CYP2C9 in HLMs, and cyp1a2, cyp2b1, cyp2d1, and cyp2e1 in vivo. Our data recommend caution when avitinib was taken simultaneously with drugs metabolized by CYP450 enzymes.
Topics: Animals; Area Under Curve; Chromatography, High Pressure Liquid; Cytochrome P-450 Enzyme Inhibitors; Cytochrome P-450 Enzyme System; Drug Interactions; Humans; Inhibitory Concentration 50; Male; Microsomes, Liver; Pharmaceutical Preparations; Protein Kinase Inhibitors; Pyrimidines; Rats; Rats, Sprague-Dawley; Reproducibility of Results; Tandem Mass Spectrometry
PubMed: 34456561
DOI: 10.2147/DDDT.S323186 -
Forensic Science International Oct 2021Cocaine is a naturally occurring psychostimulant drug available worldwide. Drug trafficking networks adulterate pure cocaine with cutting agents to increase their...
Cocaine is a naturally occurring psychostimulant drug available worldwide. Drug trafficking networks adulterate pure cocaine with cutting agents to increase their earnings. This study presents a descriptive statistical analysis of the cutting agents found in 2118 cocaine samples that were seized in the Northern Region of Colombia (in the period 2015-2017). The data used in this study was drawn from the GC-MS analytical reports of the National Institute of Legal Medicine and Forensic Sciences -Colombia, Northern Region. Results showed diverse cutting agents in seized cocaine samples, from which the most commonly used are caffeine, phenacetin, lidocaine, imidazole and levamisole. In addition, cocaine samples showed different mixtures of the above cutting agents, predominantly caffeine/phenacetin and caffeine/lidocaine/phenacetin mixtures.
Topics: Aporphines; Caffeine; Cocaine; Codeine; Colombia; Drug Contamination; Drug Trafficking; Humans; Imidazoles; Levamisole; Lidocaine; Phenacetin; Spatio-Temporal Analysis; Tetramisole
PubMed: 34450541
DOI: 10.1016/j.forsciint.2021.110911 -
Journal of Personalized Medicine Jul 2021Cytochrome P450 1A2 (CYP1A2), which accounts for approximately 13% of the total hepatic cytochrome content, catalyzes the metabolic reactions of approximately 9% of...
Cytochrome P450 1A2 (CYP1A2), which accounts for approximately 13% of the total hepatic cytochrome content, catalyzes the metabolic reactions of approximately 9% of frequently used drugs, including theophylline and olanzapine. Substantial inter-individual differences in enzymatic activity have been observed among patients, which could be caused by genetic polymorphisms. Therefore, we functionally characterized 21 novel CYP1A2 variants identified in 4773 Japanese individuals by determining the kinetic parameters of phenacetin -deethylation. Our results showed that most of the evaluated variants exhibited decreased or no enzymatic activity, which may be attributed to potential structural alterations. Notably, the Leu98Gln, Gly233Arg, Ser380del Gly454Asp, and Arg457Trp variants did not exhibit quantifiable enzymatic activity. Additionally, three-dimensional (3D) docking analyses were performed to further understand the underlying mechanisms behind variant pharmacokinetics. Our data further suggest that despite mutations occurring on the protein surface, accumulating interactions could result in the impairment of protein function through the destabilization of binding regions and changes in protein folding. Therefore, our findings provide additional information regarding rare CYP1A2 genetic variants and how their underlying effects could clarify discrepancies noted in previous phenotypical studies. This would allow the improvement of personalized therapeutics and highlight the importance of identifying and characterizing rare variants.
PubMed: 34442334
DOI: 10.3390/jpm11080690 -
Molecules (Basel, Switzerland) Jul 2021The thermodynamic properties of phenacetin in solid state and in saturated conditions in neat and binary solvents were characterized based on differential scanning...
The thermodynamic properties of phenacetin in solid state and in saturated conditions in neat and binary solvents were characterized based on differential scanning calorimetry and spectroscopic solubility measurements. The temperature-related heat capacity values measured for both the solid and melt states were provided and used for precise determination of the values for ideal solubility, fusion thermodynamic functions, and activity coefficients in the studied solutions. Factors affecting the accuracy of these values were discussed in terms of various models of specific heat capacity difference for phenacetin in crystal and super-cooled liquid states. It was concluded that different properties have varying sensitivity in relation to the accuracy of heat capacity values. The values of temperature-related excess solubility in aqueous binary mixtures were interpreted using the Jouyban-Acree solubility equation for aqueous binary mixtures of methanol, DMSO, DMF, 1,4-dioxane, and acetonitrile. All binary solvent systems studied exhibited strong positive non-ideal deviations from an algebraic rule of mixing. Additionally, an interesting co-solvency phenomenon was observed with phenacetin solubility in aqueous mixtures with acetonitrile or 1,4-dioxane. The remaining three solvents acted as strong co-solvents.
Topics: Phenacetin; Physical Phenomena; Solubility; Solvents; Temperature; Thermodynamics; Water
PubMed: 34279418
DOI: 10.3390/molecules26134078 -
Se Pu = Chinese Journal of... Sep 2020The advantages of capillary electrophoresis, such as small sample consumption, high separation efficiency, and multiple separation modes, have been known for decades....
The advantages of capillary electrophoresis, such as small sample consumption, high separation efficiency, and multiple separation modes, have been known for decades. However, exploring unique capillary electrophoresis techniques for the analysis of fluid drugs in living bio-systems remains an important and urgent task. Owing to the similar structures and mass-to-charge ratios of antipyretic analgesic drugs, efficient baseline separation of these analytes by capillary zone electrophoresis method cannot be easily achieved. Micellar electrokinetic chromatography can improve the baseline separation of these drugs, but the substantial amounts of non-volatile surfactants (such as sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium deoxycholate and cetylammonium bromide) in running buffer solutions would pollute the ion source during mass spectrometric analysis. For this reason, it is difficult to analyze unknown drugs by capillary electrophoresis-electrospray ionization-mass spectrometry. To overcome these drawbacks, much attention has been paid to capillary electrochromatography (CEC) because combines the high separation efficiency of capillary electrophoresis with the high selectivity of high performance liquid chromatography (HPLC). Recent challenges encountered in open-tubular capillary electrochromatography (OT-CEC) expanding the range of suitable functional polymer monomers and improvement of the separation efficiency by tuning the characteristics of the polymer coatings without using any organic solvent additives. In this study, a protocol based on OT-CEC using a block co-polymer coating is proposed for the analysis of three test antipyretic analgesic drugs (4-aminoantipyrine, antipyrine and phenacetin), without adding organic solvents and surfactants in the running buffer solutions. First, an amphiphilic block co-poly(styrene-co-glycidyl methacrylate) (P(St-GMA)), was synthesized by reversible addition-fragmentation chain transfer polymerization under mild conditions. Then, P(St-GMA) was coated onto the capillary surface, and an OT-CEC analysis was performed. Next, the effect of some key factors, including the polymerization time for obtaining P(St-GMA) with different molecular weights, coating concentrations of the block copolymer, the species of the running buffer solutions, pH and concentrations of the running buffer solutions, and organic solvent additives, on the OT-CEC separation efficiency were investigated. Under the optimized conditions with 50.0 mmol/L NaAc-HAc as the running buffer solution at pH 5.7, the three test antipyretic analgesic drugs were base-line separated by the constructed OT-CEC system. Good linear relationships between peak area and concentration of the test analytes in the range of 8.0-2.5×10 μmol/L were obtained ( ≥ 0.995). The limits of detection (LODs) were 1.0-2.5 μmol/L. Furthermore, the reason for the OT-CEC separation efficiency was clarified based on the decreased electro-osmotic flow in the coated capillary compared with that in the uncoated capillary. Finally, the proposed OT-CEC assay without using any organic solvents and surfactants as additives was applied for analysis of the three test antipyretic analgesic drugs in rat serum samples. Importantly, it was found that despite peak tailing, the OT-CEC separation efficiency of the drugs was dramatically enhanced because the block co-polymer could self-assemble in the solution and form pseudo-micelles, which further increased the interactions between the P(St-GMA) and these drugs. Our results not only reveal the great potential of block co-polymer coatings in OT-CEC for the analysis of drugs in real biological samples, but also serve asa platform for the preparation of diverse block co-polymers to be used in OT-CEC analysis. We believe that in the near future, the peak tailing problem in OT-CEC analysis can be resolved by using the designed unique block co-polymers, which possess a greater number of functional sites, as coatings and by appropriately tuning the interactions between the analytes and the coatings.
Topics: Analgesics; Animals; Antipyretics; Capillary Electrochromatography; Micelles; Polymers; Rats
PubMed: 34213278
DOI: 10.3724/SP.J.1123.2020.01006