Three-minute nebulization of gentamicin in healthy dogs results in therapeutic concentrations in bronchoalveolar lavage fluid while remaining below the toxic range values in blood.

OBJECTIVE: To determine and compare the concentration of gentamicin in the lower airways and serum of healthy spontaneously breathing dogs after nebulization with 5% undiluted gentamicin during 3 versus 10 minutes. ANIMALS: 10 healthy experimental Beagles. METHODS: This was a prospective crossover study. A standardized bronchoalveolar lavage (BAL) procedure was performed in each dog after 1 week of administration of each of 2 different gentamicin nebulization protocols separated by a 1-week washout period. The 2 protocols consisted of nebulization of 5% undiluted gentamicin (50 mg/mL) twice daily either during 10 minutes per session (± 95 mg; 10-minute protocol) or 3 minutes per session (± 28 mg; 3-minute protocol). BAL fluid (BALF) was obtained under general anesthesia using a bronchoscope within 15 minutes after administration of the last nebulization. Blood was collected within 5 minutes after BALF collection. BALF and serum gentamicin concentrations were determined by particle-enhanced turbidimetric inhibition immunoassay. Concentrations between protocols were compared using a paired t test. RESULTS: Both BALF and serum gentamicin concentrations were higher after the 10-minute protocol compared with the 3-minute protocol (mean ± SD: 2.41 ± 0.87 mg/L vs 1.25 ± 0.31 mg/L, P = .001; and 1.02 ± 0.59 mg/L vs 0.31 ± 0.24 mg/L, P < .0001 in BALF and serum, respectively), while the BALF-to-serum ratio did not differ between the protocols (3.75 [1.37 to 5.75] (median [IQR]) in the 3-minute protocol vs 2.48 [2.02 to 2.67] in the 10-minute protocol; P = .754). CLINICAL RELEVANCE: A 3-minute nebulization of gentamicin seems to achieve sufficient concentrations of gentamicin in the BALF to have good efficacy against aminoglycoside-sensitive bacteria while remaining below the toxic range values in blood.

An Intravenous Pharmacokinetic Study of Cannabidiol Solutions in Piglets through the Application of a Validated Ultra-High-Pressure Liquid Chromatography Coupled to Tandem Mass Spectrometry Method for the Simultaneous Quantification of CBD and Its Carboxylated Metabolite in Plasma.

Cannabidiol (CBD) has multiple therapeutic benefits that need to be maximized by optimizing its bioavailability. Numerous formulations are therefore being developed and their pharmacokinetics need to be studied, requiring analytical methods and data from intravenous administration. As CBD is susceptible to hepatic metabolism, the requirement of any method is to quantify metabolites such as 7-COOH-CBD. We demonstrated that CBD and 7-COOH-CBD could be simultaneously and correctly quantified in piglet plasma by using an UHPLC-MS/MS technique. The validated method allowed for an accurate bioanalysis of an intravenously injected solution consisting of CBD-HPßCD complexes. The experimental pharmacokinetic profile of CBD showed multi-exponential decay characterized by a fast apparent distribution half-life (0.25 h) and an elimination half-life of two hours. The profile of 7-COOH-CBD was not linked with the first-pass metabolism, since 80% of the maximum metabolite concentration was reached at the first sampling time point, without any decrease during the period of study. A two-compartment model was optimal to describe the experimental CBD profile. This model allowed us to calculate macro-micro constants and volumes of distribution (Vss = 3260.35 ± 2286.66 mL) and clearance (1514.5 ± 261.16 mL·h-1), showing that CBD is rapidly distributed to peripheral tissues once injected and slowly released into the bloodstream.

Intravenous lipid emulsion for a life-threatening prothipendyl intoxication.

Prothipendyl, a lipophilic neuroleptic drug, requires a careful dosage regimen due to its potential side effects, including life-threatening arrhythmias.This report outlines a case of severe prothipendyl intoxication, its management and the successful utilisation of Intralipid, an intravenous lipid emulsion, in treating ventricular arrhythmia postmassive prothipendyl ingestion. Additionally, the mechanism of action of Intralipid and the rebound concentration of the lipophilic drug in such scenarios are discussed.

Intranasal and Serum Gentamicin Concentration: Comparison of Three Topical Administration Protocols in Dogs.

Antimicrobials' topical administration efficacy has not been assessed in dogs with upper respiratory tract disease. The aim was to compare the concentration of gentamicin in nasal lavage fluid (NALF) and in serum after three topical protocols. This was a prospective crossover study of ten healthy dogs. Gentamicin was nebulized for a duration of 1 week, twice a day, for 10 min in the first protocol (10-min protocol) and for 3 min in the second protocol (3-min protocol), while the third protocol consisted of the administration of 0.25 mL of gentamicin in each nostril (drop protocol). Median concentrations of gentamicin in NALF were 9.39 µg/mL (8.12-19.97 interquartile range), 4.96 µg/mL (4.60-6.43) and 137.00 µg/mL (110.5-162.00) in the 10-min protocol, 3-min protocol and drop protocol, respectively. The result for the drop protocol was significantly higher than those of both nebulization protocols in NALF (p = 0.039). In serum, the gentamicin concentration was 0.98 µg/mL (0.65-1.53) and 0.25 µg/mL (0.25-0.44) in the 10-min and 3-min protocols, respectively. Gentamicin was not detected in the serum of seven out of ten dogs in the drop protocol, and gentamicin was significantly higher in the 10-min protocol compared to the drop protocol (p = 0.001). This study found that the 10-min, 3-min and drop protocols achieved superior concentrations in NALF compared to the minimum inhibitory concentration for gentamicin-sensitive bacteria, while remaining below the toxic values in blood.

Cannabidiol in urine is not a proof of CBD consumption-lesson learned from urine sample analysis in routine caseworks.

PURPOSE: Cannabidiol (CBD) has been gaining popularity in recent years. Knowing that CBD products can contain more tetrahydrocannabinol (THC) than expected, interpretation of cannabinoids concentration in urine can be tricky, especially when low amounts of THC and CBD are found. Moreover, interpretation can also be difficult due to interindividual variation in pharmacokinetics. The objective of this work was to take a critical look at the data from our daily practice as a toxicology laboratory. METHODS: We have collected results obtained in a first batch of 1074 urine samples submitted to cannabinoids analysis, and results of cannabinoids content of a second batch of 719 seized materials. RESULTS: CBD was detected in 163 urine specimens (15%). Its concentration was higher than the limit of quantification of 5 ng/mL in 108 samples only (10% of the sampling population). Most of CBD-positive samples were associated with a high THC-COOH concentration (> 500 ng/mL in 63.8% of CBD-positive samples) suggesting only a few CBD consumers in our population. Cannabinoids composition of seized plant materials (drug type at first glance) revealed CBD in 110 of them (15% of the sampling population), with a concentration mostly below 1%. All of the resin samples were CBD positive, and contained more THC compared to flowers. CONCLUSIONS: We can conclude that urine samples from drug-type cannabis users contained a low amount of CBD, what was not described previously. These findings are useful for the interpretation of cannabinoids results in daily practice.

Biochip array technology for new psychoactive substances detection in biological samples: Evaluation of the specificity of the Randox Evidence Investigator®.

BACKGROUND: The need to detect new psychoactive substances in biological samples is of crucial interest. In this paper, the specificity of a benchtop immunoanalyzer commercialized by Randox was evaluated on real patient samples. METHOD: The Evidence Investigator was assessed to screen for NPS on 80 serum and urine samples coming from patients admitted to the emergency department. Targeted NPS were included in various categories such as synthetic cannabinoids, opioids and benzodiazepines. Results were compared with a chromatographic technique coupled with mass spectrometry. RESULTS: No NPS was detected by the reference technique. Concerning immunoanalysis, some piperazines were positive, caused by the presence of medicine containing this chemical structure. Clonazepam and fentanyl derivatives were confirmed in some cases, but sometimes the positivity was explained by other opiates or benzodiazepines, which also explained two samples falsely positive for etizolam. CONCLUSIONS: The Randox Evidence Investigator was rapid and easy to use. It can be used as a first intention but always followed by a more specific technique in order to detect false positive result.

Potential 2-Aminoindane Fatality Invalidated by Careful Mass Spectrometric Analysis.

We describe herewith the case of a patient presenting to the emergency department for worsening ear-nose-throat symptoms. As chemsex was evocated by the family, patient's serum was submitted to a new psychoactive substances screening. After a simple liquid-liquid extraction, serum was injected on a high-resolution mass spectrometer using quite usual conditions (C18 column, gradient mode with acidic buffer, methanol and acetonitrile). An almost perfect match with 2-aminoindane (2-AI) was observed considering that the precursor ion was present in the sample but absent in the commercial library. Literature concerning 2-AI is sparse, and further investigations were undertaken. After injection of the reference standard, a small retention time shift has been observed (0.3 min) between the standard and the sample. The case was only closed while spiking the sample with the standard, giving rise to two distinct peaks. As a result, 2-AI was then considered as absent from the sample and death was attributed only to infection. Moreover, a rapid liquid chromatography-tandem mass spectrometry method dedicated to 2-AI was developed. It generated the same false-positive result highlighted by significant differences observed in ion ratios (2.37 for the sample versus 6.62 for the neat standard).

Metformin-Induced Lactic Acidosis: A Question of Time.

Metformin is an oral antidiabetic largely prescribed in the treatment of type II diabetes. Overdose is associated with life-threatening lactic acidosis. We report the case of the highest metformin concentration ever described secondary to a voluntary suicidal intake. The patient developed a severe lactic acidosis and hemodynamic shock successfully treated with high-flow hemofiltration. Time to start extrarenal epuration is capital to avoid poor evolution.

Validation of an UHPLC/DAD method for the determination of cannabinoids in seized materials: Analysis of 213 samples sold in Belgian CBD shops.

PURPOSE: Nowadays, (-)-cannabidiol (CBD) is gaining popularity for the treatment of various problems and can be found easily in many stores in Belgium. However, such product must comply with the law: if the total tetrahydrocannabinol (THC) content [(-)-Δ9-tetrahydrocannabinol + (-)-Δ9-tetrahydrocannabinolic acid A (THC-A)] is higher than 0.2%, it is considered as narcotic by the Belgian legislation. In this context, we have developed a method to quantify major cannabinoids (THC, THC-A, CBD, cannabidiolic acid, cannabigerolic acid, cannabigerol and cannabinol) in plant material. METHODS: After drying, a liquid-liquid extraction was performed on plant materials, followed by dilutions. Extracts were analyzed by ultra-high-performance liquid chromatography combined with a photodiode array detector. Mobile phases consisted of methanol and 0.1% formic acid in water applied in a 16-minute gradient mode. After validating the method, it was applied to 213 samples seized by the police in CBD shops. RESULTS: The method fulfilled the criteria in terms of specificity, calibration curve, precision, trueness and dosing range. Total THC content ranged from 0.14 to 1.17% (median 0.38%) with 110 samples exceeding the Belgian legal threshold of 0.2%. The amounts measured in the samples varied greatly, some were 6 times below the amount labelled on the packaging, others showed a concentration 4 times higher than stated on the package. Same strain also showed concentration differences from shop to shop. CONCLUSION: Our method was successfully validated and applied to samples seized in CBD shops. Half of the products exceeded the Belgian legal threshold. THC and CBD concentrations discrepancies showed that products sold in CBD shops are not pharmaceutical grade.

Death following consumption of MDAI and 5-EAPB.

5-(2-ethylaminopropyl)benzofuran (5-EAPB) and 5,6-methylenedioxy-2-aminoindane (MDAI) are two new psychoactive substances (NPS) exhibiting MDMA-like properties. In this paper, we report the case of a 28-years old man, known as drug addict, found dead at home, with two unidentified powders next to him. External examination by the forensic pathologist was unremarkable but no autopsy was performed. Powders, blood and urine (which were the only samples available) were submitted to general unknown screening by high pressure liquid chromatography with a diode array detector (HPLC-DAD) and ultra high pressure liquid chromatography with a time-of-flight detector (UPLC-TOF-MS), after liquid-liquid extraction for biological samples, or simple dilution for powders. Analysis revealed 68% of MDAI in one powder and 87% of 5-EAPB in the other one. Significant levels of the same substances were found in blood (MDAI: 2.09 mg/L and 5-EAPB: 6.45 mg/L). The cause of death was therefore attributed to the consumption of these NPS since screening for other drugs of abuse and for alcohol was negative (oxazepam was found in urine only). 5-methylaminopropylbenzofuran (5-MAPB) and 5-aminopropylbenzofuran (5-APB) were also found in blood (0.089 and 0.546 mg/L, respectively) and urine (1.00 and 4.88 mg/L, respectively). In addition to the inherent complexity of NPS identification by itself, another analytical difficulty in this case was the identification of the EAPB positional isomer. Our routine screening methods were not able to distinguish the positional isomer, but an additional classical gas chromatography technique was able to make the distinction. Anyway, in our case, this issue was simplified thanks to the availability of a relatively pure powder that was analyzed by nuclear magnetic resonance (NMR).

Urinary levels of bisphenol A, triclosan and 4-nonylphenol in a general Belgian population.

Bisphenol A, triclosan and 4-nonylphenol are among the endocrine disruptors which are widely used in daily products. In this study, we reported total urinary levels of bisphenol A, triclosan and 4-nonylphenol, in order to evaluate the baseline contamination of a general population in Belgium. Bisphenol A and triclosan were detected in respectively 97.7% and 74.6% of the samples examined demonstrating that the general Belgian population is extensively exposed to both chemicals. On the other hand, 4-nonylphenol was not detected in any urine samples analyzed, suggesting either low exposure, inadequate biomarker, or that urine is an inappropriate biological matrix for assessing exposure to nonylphenol commercial mixtures. Geometric mean concentration was determined for bisphenol A at 2.55 µg/l and for triclosan at 2.70 µg/l. No significant difference was observed between levels and gender for both bisphenol A and triclosan. When classified by age, the 20-39 year group showed the highest triclosan levels, while all age groups seemed to be similarly exposed to bisphenol A. Both bisphenol A and triclosan urinary levels were not correlated with creatinine excretion in our healthy population, questioning the relevance of the creatinine adjustment in reporting these chemical levels. Bisphenol A levels in urine of people living in the same home and collected on the same time were fairly correlated, confirming the assumption that dietary intake would be the primary route of exposure. Triclosan urinary levels were not correlated with bisphenol A levels.

New pyridobenzoxazepine derivatives derived from 5-(4-methylpiperazin-1-yl)-8-chloro-pyrido[2,3-b][1,5]benzoxazepine (JL13): chemical synthesis and pharmacological evaluation.

A series of new pyridobenzoxazepine derivatives with various heterocyclic amine side chains were synthesized to explore two main parameters related to the distal basic nitrogen. These compounds were tested for their affinity for dopamine D(2L) and D(4), serotonin 5-HT(1A) and 5-HT(2A), and adrenergic α(2A) receptors in comparison with 5-(4-methylpiperazin-1-yl)-8-chloro-pyrido[2,3-b][1,5]benzoxazepine, JL13 (1), and other diarylazepine derivatives. In terms of multireceptor target strategy, 2 and 5 present the most promising in vitro binding profile. Bulky, polar, and more flexible side chains are not favorable in this context. Compounds 2 and 5 were tested in adult rats to evaluate their long-term effects on dopamine and serotonin receptors density in different brain areas. Similar to 1 and other second-generation antipsychotic drugs, repeated treatment with 2 significantly increased D(1) and D(4) receptors in nucleus accumbens and caudate putamen and D(2) receptors in medial prefrontal cortex and hippocampus, while 5 significantly increased D(2) and D(4) receptors in nucleus accumbens. In addition, 2 increased 5-HT(1A) and decreased 5-HT(2A) receptors in cerebral cortex. In contrast, 5 did not alter levels of any 5-HT receptor subtype in any brain region examined. These results encourage further development of 2 as a novel second-generation antipsychotic agent.