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Purpose Long-term regular use of ketamine has been reported to be associated with severe symptomatic urinary tract problems. Methoxetamine, an arylcyclohexylamine derivative of ketamine, is marketed as a “bladder safe” derivative of ketamine, and no cases of acute toxicity following analytically confirmed methoxetamine use have been reported to date. We report here a case series of three individuals with acute toxicity related to the analytically confirmed use of methoxetamine. Case series Three patients aged between 28 and 42 years presented to the Emergency Department (ED) on unrelated occasions having used methoxetamine. Clinical features were suggestive of a “dissociative/catatonic” state similar to that seen with ketamine; in addition, they had clinical features of acute sympathomimetic toxicity with significant tachycardia and hypertension. All were managed with low-dose benzodiazepines and discharged home once their symptoms/signs had settled. Toxicological screening Serum collected at the time of presentation to the ED was analysed qualitatively and quantitatively by gas chromatography–mass spectrometry. Serum concentrations ranged from 0.09 to 0.2 mg/L; in addition, detectable levels of 6-APB/5-APB were found in one of the patients. Conclusions These three analytically confirmed cases demonstrate that acute methoxetamine-related toxicity is associated with both “dissociative” and “sympathomimetic” clinical features. The information from these three cases is useful to clinical pharmacologists, not only in managing individuals with acute methoxetamine toxicity but also in advising the appropriate legislative authorities on the risk of acute harm related to methoxetamine use. Further work is needed to determine whether methoxetamine is more “bladder friendly” than ketamine, as has been suggested by those marketing methoxetamine.

Introduction In hereditary tyrosinemia type 1 (HT1) patients, the dose of NTBC that leads to the absence of toxic metabolites such as succinylacetone (SA) is still unknown. Therefore, the aims of this study were to investigate the variation and concentrations of 2-(2-nitro-4-trifluormethyl-benzyl)-1,3-cyclohexanedione (NTBC) during the day in relation to the detection of SA, while comparing different dosing regimens. Methods All patients were treated with NTBC (mean 1.08 ± 0.34 mg/kg/day) and a low phenylalanine-tyrosine diet. Thirteen patients received a single dose of NTBC and five patients twice daily. Home bloodspots were collected four times daily for three consecutive days measuring NTBC and SA concentrations. Statistical analyses were performed by using mixed model analyses and generalized linear mixed model analyses to study variation and differences in NTBC concentrations and the correlation with SA, respectively. Results NTBC concentrations varied significantly during the day especially if NTBC was taken at breakfast only ( p  = 0.026), although no significant difference in NTBC concentrations between different dosing regimens could be found ( p  = 0.289). Momentary NTBC concentrations were negatively correlated with SA ( p  < 0.001). Quantitatively detectable SA was only found in subjects with once daily administration of NTBC and associated with momentary NTBC concentrations <44.3 μmol/l. Discussion NTBC could be less stable than previously considered, thus dosing NTBC once daily and lower concentrations may be less adequate. Further research including more data is necessary to establish the optimal dosing of NTBC.

Nitisinone (NTBC) is used in the treatment of disorders affecting the tyrosine pathway, including hereditary tyrosinemia type I, alkaptonuria, and neuroblastoma. An inappropriate dosage of this therapeutic drug causes side effects; therefore, it is necessary to develop a rapid and sensitive method to monitor the content of NTBC in patients’ blood. This study aimed to develop anew polymeric sorbent containing β-cyclodextrin (β-CD) derivatives grafted on silica gel to effectively extract NTBC from model physiological fluids. The inclusion complex formed between β-CD and NTBC was examined by proton nuclear magnetic resonance spectroscopy. The novel sorbents with derivatives of β-CD were prepared on modified silica gel using styrene as a comonomer, ethylene glycol dimethacrylate as a crosslinking agent, and 2,2′-azo-bis-isobutyronitrile as a polymerization initiator. The obtained products were characterized via Fourier transform infrared spectroscopy and then used as sorbents as part of a solid phase extraction technique. High NTBC recovery (70%indicated that the developed polymeric sorbent may be suitable for extracting this compound from patients’ blood samples.

Most gunshot entrance sites on human victims are localized in clothed body regions. Except for the use of lead-free ammunition, a positive color reaction of the sodium rhodizonate test indicates a primary target hit by the bullet. Any lead residue pattern in the area around the entrance hole allows approximate conclusions as to the firing distance in close and intermediate range shots, whereas the presence of a bullet wipe denotes an entrance site. A criminal case gave rise to an experimental study to clarify whether a blood-soaked garment being shot at as a primary target may lack a bullet wipe around the entrance hole. Distant-range shots were fired with a semi-automatic pistol (Heckler & Koch, Mod. USP Compact, cal. 9-mm Luger) using cartridges with jacketed round-nose bullets and a Sinoxid primer containing lead styphnate. In fabrics saturated with fluid blood, a wide area around the bullet entrance was densely covered with rhodizonate-positive microparticles simulating gunshot residues (GSR) from a close-range shot. In shots to fabrics oversaturated with blood, a typical bullet wipe was lacking, whereas lead-containing particles were spotted in the periphery. The results are discussed with respect to the aberrant appearance of bullet entrance sites in blood-soaked fabrics.

Cyclohexanone is an industrial solvent used as a coupling agent in medical plastics. Perioperative exposure to cyclohexanone could play a role in lower scores on measures of neurodevelopmental outcomes after neonatal cardiac operations. To examine the presence and association of serum cyclohexanone level with neonatal cardiac operations and neurodevelopmental outcomes. This ad hoc secondary analysis used data from the Corticosteroid Therapy in Neonates Undergoing Cardiopulmonary Bypass randomized clinical trial. The cohort included neonates younger than 31 days and with at least 37 weeks postgestational age at surgical treatment who were enrolled at a single center between June 1, 2012, and October 31, 2016, and who had completed a neurodevelopmental assessment at age 12 months. Data were analyzed from July 8 to August 20, 2019. Serum cyclohexanone and its metabolites were measured preoperatively (prior to skin incision), postoperatively (immediately after the surgical procedure was completed), and 12 hours postoperatively. Cyclohexanone and the molar sum of its metabolites were examined at each point and as a geometric mean of all 3 points. Neurodevelopment was assessed at age 12 months with the Bayley Scales of Infant and Toddler Development III, assessing cognitive, language, and motor function composite scores standardized to a population mean (SD) of 100 (15). Linear regression models were used to determine covariate-adjusted differences in 12-month cognitive, language, and motor composite scores per interquartile range increase in cyclohexanone level or summed metabolite molar concentrations. Among 85 included neonates, mean (SD) age at surgical treatment was 9.7 (5.3) days, 49 (58%) were boys, and 54 (64%) underwent corrective repair. Mean (SD) Bayley Scales of Infant and Toddler Development III composite scores were 108.2 (12.2) for cognitive function, 104.7 (11.0) for language function, and 94.7 (15.7) for motor function. Median (interquartile range) cyclohexanone levels increased approximately 3-fold from immediately prior to surgical treatment to immediately after surgical treatment (572 [389-974] vs 1744 [1469-2291] μg/L; P = .001). In adjusted analyses, higher geometric mean cyclohexanone levels were associated with significantly lower composite scores for cognitive (-4.23; 95% CI, -7.39 to -1.06; P = .01) and language (-3.65; 95% CI, -6.41 to -0.88; P = .01) function. The difference in composite scores for motor function among infants with higher geometric mean cyclohexanone levels was not statistically significant(-3.93, 95% CI: -8.19 to 0.33, P = .07). The findings of this secondary analysis of a randomized clinical trial suggest that infants who underwent neonatal cardiac surgical treatment with cardiopulmonary bypass had substantial cyclohexanone levels, which were associated with adverse neurodevelopmental function at age 12 months. ClinicalTrials.gov identifier: NCT01579513.

NTBC (2-(2-nitro-4-trifluoromethylbenzoyl)-1,3cyclohexanedione) is the mainstay of treatment in tyrosinemia type 1 (HT 1). The current recommendation is to divide the total daily dose of NTBC into two doses. We monitored the plasma NTBC concentrations in a series of seven patients who were changed from multiple divided doses to a single daily dose of NTBC. Two additional patients were started on a single daily dose of NTBC after the diagnosis of HT 1 was established. In three patients, NTBC kinetics were performed over 6 and 24 hours, respectively. The use of multiple divided doses or a single daily dose did not significantly affect plasma NTBC concentrations or the mean daily dose needed to attain therapeutic plasma NTBC concentrations. Moreover, kinetic studies demonstrated that plasma NTBC concentrations were completely stable over a period of 24 hours with a single dose regimen, as expected given the known NTBC plasma half life of 54 hours. Although these preliminary results need to be confirmed in more patients, our findings show that administration of NTBC in a single daily dose may be as effective as a multiple-dose regimen in reaching therapeutic plasma NTBC concentrations and suppressing succinylacetone formation in patients with HT 1. In fact, single dose treatment may increase patients’ compliance with the drug treatment and improve metabolic control.

A sensitive and accurate high performance liquid chromatography with ultraviolet/visible light detection (HPLC-UV/VIS) method for the quantification of 2,6-bis-(4-hydroxy-3-methoxybenzylidene)-cyclohexanone (BHMC) in rat plasma was developed and validated. BHMC and the internal standard, harmaline, were extracted from plasma samples by a simple liquid–liquid extraction using 95% ethyl acetate and 5% methanol. Plasma concentration of BHMC and internal standard were analyzed by reversed phase chromatography using a C18 column (150 × 4.6 mm I.D., particle size 5 µm) and elution with a gradient mobile phase of water and methanol at a flow rate of 1.0 mL/min. Detection of BHMC and internal standard was done at a wavelength of 380 nm. The limit of quantification was 0.02 µg/mL. The calibration curves was linear (R2 > 0.999) over the concentration range of 0.02–2.5 µg/mL. Intra- and inter-day precision were less than 2% coefficient of variation. The validated method was then applied to a pharmacokinetic study in rats by intravenous administration of BHMC at a single dose of 10 mg/kg. Pharmacokinetic parameters such as half-life, maximum plasma concentration, volume of distribution, clearance and elimination rate constant for BHMC were calculated.

Introduction: Sulcotrione is a herbicidal agent belonging to the family of triketones. Sulcotrione herbicides are used for weed control in maize and flax crops. To date, no cases of human poisoning had been reported in the literature linked to different herbicidal agents in the triketone family. We report here on two cases of the voluntary ingestion of this substance in the form of the branded product MikadoTM, which were recorded by the Angers Poison Centre. Case report: Both cases of voluntary ingestion constituted attempted suicide, and involved two men aged 30 and 37 years. Their symptoms linked to sulcotrione were limited to vomiting, despite elevated plasma concentrations of sulcotrione. In one case, hypertyrosinemia has been demonstrated. The outcome was favourable in both patients and at follow up, no ocular disorders were observed. In the second case, hypotension and transient renal failure could be linked to the concomitant ingestion of chlorophenoxy herbicides. Discussion: In animal toxicity studies, sulcotrione inhibit 4-hydro-phenylpyruvate dioxygenase leading to hypertyrosinemia and corneal opacities. In both cases, no ocular disorders were observed despite hypertyrosinemia in one case. These case reports were consistent with the animal toxicology findings concerning triketones, and particularly their relative safety in mammals following acute poisoning. However it seems prudent to monitor plasma tyrosine concentrations and to screen prospectively for corneal deposits if further acute intoxication events occur.

BackgroundAlkaptonuria (AKU) is a serious genetic disease characterised by premature spondyloarthropathy. Homogentisate-lowering therapy is being investigated for AKU. Nitisinone decreases homogentisic acid (HGA) in AKU but the dose-response relationship has not been previously studied.MethodsSuitability Of Nitisinone In Alkaptonuria 1 (SONIA 1) was an international, multicentre, randomised, open-label, no-treatment controlled, parallel-group, dose-response study. The primary objective was to investigate the effect of different doses of nitisinone once daily on 24-h urinary HGA excretion (u-HGA24) in patients with AKU after 4 weeks of treatment. Forty patients were randomised into five groups of eight patients each, with groups receiving no treatment or 1 mg, 2 mg, 4 mg and 8 mg of nitisinone.FindingsA clear dose-response relationship was observed between nitisinone and the urinary excretion of HGA. At 4 weeks, the adjusted geometric mean u-HGA24 was 31.53 mmol, 3.26 mmol, 1.44 mmol, 0.57 mmol and 0.15 mmol for the no treatment or 1 mg, 2 mg, 4 mg and 8 mg doses, respectively. For the most efficacious dose, 8 mg daily, this corresponds to a mean reduction of u-HGA24 of 98.8% compared with baseline. An increase in tyrosine levels was seen at all doses but the dose-response relationship was less clear than the effect on HGA. Despite tyrosinaemia, there were no safety concerns and no serious adverse events were reported over the 4 weeks of nitisinone therapy.ConclusionsIn this study in patients with AKU, nitisinone therapy decreased urinary HGA excretion to low levels in a dose-dependent manner and was well tolerated within the studied dose range.Trial registration numberEudraCT number: 2012-005340-24. Registered at ClinicalTrials.gov: NCTO1828463.

Nitisinone decreases homogentisic acid (HGA) in Alkaptonuria (AKU) by inhibiting the tyrosine metabolic pathway in humans. The effect of different daily doses of nitisinone on circulating and 24 h urinary excretion of phenylalanine (PA), tyrosine (TYR), hydroxyphenylpyruvate (HPPA), hydroxyphenyllactate (HPLA) and HGA in patients with AKU was studied over a four week period. Forty AKU patients, randomised into five groups of eight patients, received doses of 1, 2, 4 or 8 mg of nitisinone daily, or no drug (control). Metabolites were analysed by tandem mass spectrometry in 24 h urine and serum samples collected before and after nitisinone. Serum metabolites were corrected for total body water and the sum of 24 hr urine plus total body water metabolites of PA, TYR, HPPA, HPLA and HGA were determined. Body weight and urine urea were used to check on stability of diet and metabolism over the 4 weeks of study. The sum of quantities of urine metabolites (PA, TYR, HPPA, HPLA and HGA) were similar pre- and post-nitisinone. The sum of total body water metabolites were significantly higher post-nitisinone (p < 0.0001) at all doses. Similarly, combined 24 hr urine:total body water ratios for all analytes were significantly higher post-nitisinone, compared with pre-nitisinone baseline for all doses (p = 0.0002 – p < 0.0001). Significantly higher concentrations of metabolites from the tyrosine metabolic pathway were observed in a dose dependant manner following treatment with nitisinone and we speculate that, for the first time, experimental evidence of the metabolite pool that would otherwise be directed towards pigment formation, has been unmasked.