Intoxicación por fenitoína. Reacción cruzada con barbitúricos / Phenytoin intoxication. Cross-reaction with barbiturates

Las intoxicaciones suponen un motivo frecuente de consulta en Pediatría. El cribado toxicológico en orina es una herramienta de diagnóstico rápido y bajo coste, pero debemos tener precaución en su interpretación, ya que existen reacciones cruzadas con otros fármacos de estructura química similar. Se describe el caso clínico de un paciente de 11 años con afectación neurológica y resultados positivos para barbitúricos en orina. La confirmación de niveles elevados de fenitoína en sangre permite confirmar el diagnóstico y la reactividad cruzada de los resultados en orina

Intoxications are a common reason for consultation in Pediatrics. Urine toxicology screening is a rapid and low-cost tool, but these results have to be interpreted with caution due to cross reactions with other drugs with similar chemical structure. We describe the clinical case of a 11 years old patient with neurological involvement and positive results for barbiturates in urine. Confirmation of high levels of phenytoin in blood guaranteed the diagnosis and cross-reaction results in urine

Intoxicación por fenitoína. Reacción cruzada con barbitúricos / Phenytoin intoxication. Cross-reaction with barbiturates

Las intoxicaciones suponen un motivo frecuente de consulta en Pediatría. El cribado toxicológico en orina es una herramienta de diagnóstico rápido y bajo coste, pero debemos tener precaución en su interpretación, ya que existen reacciones cruzadas con otros fármacos de estructura química similar. Se describe el caso clínico de un paciente de 11 años con afectación neurológica y resultados positivos para barbitúricos en orina. La confirmación de niveles elevados de fenitoína en sangre permite confirmar el diagnóstico y la reactividad cruzada de los resultados en orina

Intoxications are a common reason for consultation in Pediatrics. Urine toxicology screening is a rapid and low-cost tool, but these results have to be interpreted with caution due to cross reactions with other drugs with similar chemical structure. We describe the clinical case of a 11 years old patient with neurological involvement and positive results for barbiturates in urine. Confirmation of high levels of phenytoin in blood guaranteed the diagnosis and cross-reaction results in urine

Triage DOA® versus INSTANT-VIEW M-1® in Urinary Drug Screening for Acute Drug Poisoning: A Prospective Cross-sectional Study.

Objective In the management of patients with suspected acute drug poisoning, a screening test using the patient's urine is usually performed. The Triage DOA® and INSTANT-VIEW M-1® kits are two commonly used point-of-care screening kits in Japan. However, the relationship between the results of these screening kits and the blood concentration of the poisoning drug is not clear. In this study, we evaluated which kit is more useful for acute drug poisoning screening based on a comparison of their results with the results of a serum drug analysis. Methods This prospective cross-sectional study investigated all patients with acute drug poisoning admitted to a general hospital in Tokyo, Japan, over a nine-month period. The Triage DOA® and INSTANT-VIEW M-1® screening kits were used, and a qualitative serum analysis was conducted simultaneously in all cases. We compared the kits for use in screening patients with acute drug poisoning and evaluated the utility of the kits. Results For the 117 patients enrolled in this study, the 2 kits showed different sensitivities to benzodiazepines (Triage®, 78.6%; INSTANT-VIEW®, 90.5%). Both kits showed high sensitivity to barbiturates (Triage®, 87.0%; INSTANT-VIEW®, 91.3%) but low sensitivity to tricyclic antidepressants (Triage®, 25.0%; INSTANT-VIEW®, 45.8%). Conclusion Because the sensitivity varies depending on the kind of drug, it is difficult to discuss the superiority of these kits. However, this study compared the results of two types of urinary drug screening kits with the results of qualitative analysis of drugs in serum as a gold standard, providing important reference data.

Single-Dose Pharmacokinetics, Excretion, and Metabolism of Zoliflodacin, a Novel Spiropyrimidinetrione Antibiotic, in Healthy Volunteers.

Zoliflodacin is a novel spiropyrimidinetrione with activity against bacterial type II topoisomerases that inhibits DNA biosynthesis and results in accumulation of double-strand cleavages in bacteria. We report results from two phase 1 studies that investigated the safety, tolerability, and pharmacokinetics (PK) of zoliflodacin and absorption, distribution, metabolism, and excretion (ADME) after single doses in healthy volunteers. In the single ascending dose study, zoliflodacin was rapidly absorbed, with a time to maximum concentration of drug in serum (Tmax) between 1.5 and 2.3 h. Exposure increased dose proportionally up to 800 mg and less than dose proportionally between 800 and 4,000 mg. Urinary excretion of unchanged zoliflodacin was <5.0% of the total dose. In the fed state, absorption was delayed (Tmax, 4 h), accompanied by an increase in the area under the concentration-time curve (AUC) at 1,500- and 3,000-mg doses. In the ADME study (3,000 mg orally), the PK profile of zoliflodacin had exposure (AUC and maximum concentration of drug in serum [Cmax]) similar to that of the ascending dose study and a median Tmax of 2.5 h. A total of 97.8% of the administered radioactivity was recovered in excreta, with urine and fecal elimination accounting for approximately 18.2% and 79.6% of the dose, respectively. The major clearance pathway was via metabolism and elimination in feces with low urinary recovery of unchanged drug (approximately 2.5%) and metabolites accounting for 56% of the dose excreted in the feces. Zoliflodacin represented 72.3% and metabolite M3 accounted for 16.4% of total circulating radioactivity in human plasma. Along with the results from these studies and based upon safety, PK, and PK/pharmacodynamics targets, a dosage regimen was selected for evaluation in a phase 2 study in urogenital gonorrhea. (The studies discussed in this paper have been registered at ClinicalTrials.gov under identifiers NCT01929629 and NCT02298920.).

Predictive Value of Positive Drug Screening Results in an Urban Outpatient Population.

Urine drug testing (UDT) has become an essential component in the management of patients prescribed opioid analgesics for the treatment of chronic non-malignant pain. Several laboratory methods are available to monitor adherence with the pharmacological regimen and abstinence from illicit or unauthorized medications. Immunochemical screening methods are rapid and economical, but they have limitations, including lack of specificity, and confirmatory methods are often necessary to verify presumptive positive results. We analyzed the results of confirmatory assays in an outpatient setting to determine the predictive value of presumptive positive urine drug screen results using an automated immunoassay for eight common drugs or drug classes. Positive predictive values (PPVs), in descending order, were as follows: cannabinoids (100%), cocaine (100%), opiates (86.8%), benzodiazepines (74.6%), oxycodone (67.6%), methadone (44.1%) and amphetamines (9.3%). The number of positive barbiturate results was too small to be included in the statistical analysis.

Simultaneous analysis method for GHB, ketamine, norketamine, phenobarbital, thiopental, zolpidem, zopiclone and phenytoin in urine, using C18 poroshell column.

Date-rape drugs have the potential to be used in drug-facilitated sexual assault, organ theft and property theft. Since they are colorless, tasteless and odorless, victims can drink without noticing, when added to the beverages. These drugs must be detected in time, before they are cleared up from the biofluids. A simultaneous extraction and determination method in urine for GHB, ketamine, norketamine, phenobarbital, thiopental, zolpidem, zopiclone and phenytoin (an anticonvulsant and antiepileptic drug) with LC-MS/MS was developed for the first time with analytically acceptable recoveries and validated. A 4 steps liquid-liquid extraction was applied, using only 1.000mL urine. A new age commercial C18 poroshell column with high column efficiency was used for LC-MS/MS analysis with a fast isocratic elution as 5.5min. A new MS transition were introduced for barbital. 222.7>179.8 with the effect of acetonitrile. Recoveries (%) were between 80.98-99.27 for all analytes, except for GHB which was 71.46. LOD and LOQ values were found in the ranges of 0.59-49.50 and 9.20-80.80ngmL(-1) for all the analytes (except for GHB:3.44 and 6.00µgmL(-1)). HorRat values calculated (between 0.25-1.21), revealed that the inter-day and interanalist precisions (RSD%≤14.54%) acceptable. The simultaneous extraction and determination of these 8 analytes in urine is challenging because of the difficulty arising from the different chemical properties of some. Since the procedure can extract drugs from a wide range of polarity and pKa, it increases the window of detection. Group representatives from barbiturates, z-drugs, ketamine, phenytoin and polar acidic drugs (GHB) have been successfully analyzed in this study with low detection limits. The method is important from the point of determining the combined or single use of these drugs in crimes and finding out the reasons of deaths related to these drugs.

Mass spectrometric characterization of a prolyl hydroxylase inhibitor GSK1278863, its bishydroxylated metabolite, and its implementation into routine doping controls.

Drug candidates, which have the potential of enhancing athletic performance represent a risk of being misused in elite sport. Therefore, there is a need for early consideration by anti-doping authorities and implementation into sports drug testing programmes. The hypoxia-inducible factor (HIF) or prolyl hydroxylase inhibitor (PHI) GSK1278863 represents an advanced candidate of an emerging class of therapeutics that possess substantial potential for abuse in sport due to their capability to stimulate the biogenesis of erythrocytes and, consequently, the individual's oxygen transport capacity. A thorough characterization of such analytes by technologies predominantly used for doping control purposes and the subsequent implementation of the active drug and/or its main urinary metabolite(s) are vital for comprehensive, preventive, and efficient anti-doping work. In the present study, the HIF PHI drug candidate GSK1278863 (comprising a 6-hydroxypyrimidine-2,4-dione nucleus) and its bishydroxylated metabolite M2 (GSK2391220A) were studied regarding their mass spectrometric behaviour under electrospray ionization (ESI-MS/MS) conditions. Synthesized reference materials were used to elucidate dissociation pathways by means of quadrupole/time-of-flight high resolution/high accuracy tandem mass spectrometry, and their detection from spiked urine and elimination study urine samples under routine doping control conditions was established using liquid chromatography-electrospray ionization-tandem mass spectrometry with direct injection. Dissociation pathways to diagnostic product ions of GSK1278863 (e.g. m/z 291, 223, and 122) were proposed as substantiated by determined elemental compositions and MS(n) experiments as well as comparison to spectra of the bishydroxylated analogue M2. An analytical assay based on direct urine injection using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous determination of GSK1278863 in combination with its bishydroxylated metabolite M2. Validation parameters including limit of detection (0.5-1 ng/mL), linearity, specificity, ion suppression/enhancement (<10%), intra- and inter-day precision (6-22%) were determined, demonstrating the fitness-for-purpose of the assay for doping control screening of urine samples for the presence of the drug candidate and its main metabolite and for expanding current anti-doping efforts to this new class of therapeutics. However, administration study urine sample analysis suggested the use of M2 rather than the intact drug due to extensive metabolic conversion. Copyright © 2015 John Wiley & Sons, Ltd.

Hair analysis to monitor abuse of analgesic combinations containing butalbital and propyphenazone.

Butalbital, a barbiturate, is present in analgesic combinations used by headache sufferers. Overuse/abuse of these combinations may cause dependence, chronic migraine, and medication-overuse headache (MOH). MOH is difficult to manage: it improves interrupting analgesic overuse, but requires monitoring, because relapses are frequent. A gas chromatography-mass spectrometry (GC-MS) method for hair analysis has been developed and validated to document abuse of an analgesic combination containing butalbital and propyphenazone by a patient with MOH. For over ten years the patient managed her headache using eight suppositories/day of an analgesic combination containing butalbital 150mg, caffeine 75mg, and propyphenazone 375mg per suppository. An outpatient detoxification treatment was carried out. After three weeks, the patient reduced the consumption to one suppository/day. At the first control visit, after three months from the beginning of detoxification, the patient increased the use of the combination to four suppositories/day and at the second control visit, after seven months from the beginning of detoxification, she was back to eight suppositories/day. At the two control visits, a hair sample was taken for determination of butalbital and propyphenazone. Moreover blood and urine samples for determination of butalbital were drawn at the beginning of detoxification treatment and at the two control visits. With the segmental analysis of two hair samples the medication history of ten months could be estimated. In the first hair sample, collected at the first control visit, in the distal segment, butalbital and propyphenazone concentrations were, respectively, 17.5ng/mg and 56.0ng/mg, confirming the prolonged abuse; in the proximal segment, concurrently with the detoxification treatment, butalbital and propyphenazone concentrations had reduced respectively to 5.45ng/mg and 11.1ng/mg. The second hair sample, collected at the second control visit, proved the fair course of the detoxification treatment in the distal segment and signalled relapse in the abuse of the analgesic combination in the proximal segment. In the clinical context, hair analysis can be advantageously used to monitor the abuse of analgesic combinations with butalbital, common among headache patients. The validation data showed that GC-MS method developed for determination of butalbital and propyphenazone was rapid, highly sensitive, specific and selective.

In-line solid-phase extraction-capillary zone electrophoresis for the determination of barbiturate drugs in human urine.

The abuse of barbiturate drugs is widespread, and the development of methods for their efficient separation and quantification is needed. Three barbiturate drugs were preconcentrated and determined by in-line solid-phase extraction (SPE) capillary electrophoresis (CE) in urine samples. Different parameters affecting preconcentration were evaluated, such as the sample pH, the volume of the elution plug and the sample injection time. This strategy enhanced the detection sensitivity in the range of 170- to 1840-fold, compared with normal hydrodynamic injection. The method provides limits of detection (LODs) for standard samples in the range of 0.5 to 5 ng/mL with good repeatability and reproducibility values. The LODs obtained for urine samples were in the range of 5 to 60 ng/mL. The validation with human urine samples spiked with the studied compounds demonstrated the applicability of the optimized method. This method provides a reproducible and sensitive analysis of urine samples in the determination of barbiturates drugs.

Electrokinetic supercharging in CE for the separation and preconcentration of barbiturate drugs in urine samples.

Three barbiturate drugs, barbital, phenobarbital, and secobarbital were separated and analyzed by electrokinetic supercharging. The influence of different parameters on electrokinetic supercharging performance was evaluated using both univariated and multivariated optimization processes. The parameters studied were sample pH, concentration, and length of the leading and terminating electrolytes, electrokinetic injection of the sample and composition and hydrodynamic injection of the solvent plug. The leading electrolyte (50 mM NaCl) was hydrodynamically injected (50 mbar × 120 s) prior to the sample that was adjusted to pH 9.6 and electrokinetically injected at -8.5 kV for 300 s. The terminating electrolyte (100 mM of 2-(cyclohexylamino) ethanesulphonic acid) was then hydrodynamically injected (50 mbar × 140 s). The results showed that this strategy enhanced detection sensitivity around 1050-fold compared with normal hydrodynamic injection, providing detection limits ranging between 1.5 and 2.1 ng/mL for standard samples with good repeatability in terms of peak area (values of relative standard deviation, %RSD < 3). The applicability of the optimized method was demonstrated by the analysis of human urine samples spiked with the studied compounds at different concentration levels and further liquid-liquid extraction step. The estimated detection limits obtained in the urine samples extract ranged between 8 and 15 ng/mL.

Evaluation of the NexScreen and DrugCheck Waive RT urine drug detection cups.

Urine drug testing is an important tool that is commonly used to assess patient compliance with prescription regimens. Point-of-collection immunoassay devices allow for timely availability of laboratory test results to guide therapy during the same office visit. Two waived immunoassay-based urine drug screen cups were evaluated in this study. The NexScreen cup and the DrugCheck Waive RT cup claim to detect 10-12 drug classes of commonly used and/or abused drugs. This study included a sensitivity and precision challenge with 4-6 replicates at concentrations 0-150% of the manufacture's claimed cutoff, using drug-free urine spiked with purified reference standards. The stability of test results was evaluated by reading the results at intervals between five and 1,440 min. Specificity was evaluated by parallel comparison of pooled patients' specimens, representing 56 patients and 41 known drug compounds. When comparing results to validated liquid chromatography-mass spectrometry results, false positives were observed in the NexScreen cups for benzodiazepine, methamphetamine, methadone, opiates and tricyclic antidepressant tests, but there were no false negatives. The DrugCheck Waive RT cups showed false negative results for barbiturates and opiates, but no false positives. Overall, the NexScreen cup demonstrated better sensitivity than claimed, whereas the sensitivity of the DrugCheck Waive RT cup did not meet claims.

Molecularly imprinted polymer with high-fidelity binding sites for the selective extraction of barbiturates from human urine.

In this paper we describe the synthesis of a molecularly imprinted polymer (MIP) by precipitation polymerisation, with barbital as the template molecule, and the application of the barbital MIP as a molecularly selective sorbent in the solid-phase extraction (SPE) of barbiturates from human urine samples. The MIP was synthesised by precipitation polymerisation using 2,6-bis-acrylamidopyridine as the functional monomer and DVB-80 as the cross-linking agent. The spherical MIP particles produced were 4.2 ± 0.4 µm in diameter; a non-imprinted control polymer (NIP) in bead form was 4.8 ± 0.4 µm (mean±standard deviation) in diameter. The particles were packed into a solid-phase extraction cartridge and employed as a novel sorbent in a molecularly imprinted solid-phase extraction (MISPE) protocol. The MIP showed high selectivity for the template molecule, barbital, a feature which can be ascribed to the high-fidelity binding sites present in the MIP which arose from the use of 2,6-bis-acrylamidopyridine as the functional monomer. However, the MIP also displayed useful cross-selectivity for other barbiturates besides barbital. For real samples, the MIP was applied for the extraction of four barbiturates from human urine. However, due to the high urea concentration in this sample which interfere the proper interaction of barbiturates onto the MIP, a tandem system using a commercially available sorbent was developed.

Development of a dispersive liquid-liquid microextraction method for spectrophotometric determination of barbituric acid in pharmaceutical formulation and biological samples.

In this paper, a novel and simple method for the determination of trace amounts of barbituric acid in water and biological samples was developed by using dispersive liquid-liquid microextraction (DLLME) techniques combined with spectrophotometric analysis. The procedure is based on color reaction of barbituric acid with p-dimethylaminobenzaldehyde and extraction of the color product using the DLLME technique. Some important parameters such as reaction conditions and the type and volume of extraction and dispersive solvents as well as the extraction time were investigated and optimized in detail. Under the optimum conditions, the calibration graphs were linear over the range of 5.0 to 200 ng ml(-1) with limit of detection of 2.0 ng ml(-1). Relative standard deviation for five replicate determinations of barbituric acid at 50 ng ml(-1) concentration level was calculated to be 1.64%. Average recoveries for spiked samples were determined to be between 94% and 105%. The proposed method was applied for the determination of barbituric acid in pharmaceutical formulation and biological samples.

Evaluation of the integrated E-Z split key(®) cup II for rapid detection of twelve drug classes in urine.

The availability of point-of-care (POC) medical devices for drug testing has surged. Reduction in turnaround time, and hence, rapid results are attractive, particularly to acute care facilities, rehabilitation facilities and specialized clinics such as pain management clinics. Here we describe our validation results for the Integrated E-Z Split Key Cup II, a low-cost, rapid urine test that utilizes competitive immunoassay technology to detect 12 drugs or drug classes of commonly abused drugs. Positivity is based on the absence of a colored band at a labeled portion of the detection strip; a negative result produces a distinct, colored band. Using reagent-grade standards, the apparent cut-off for each of the drugs was challenged. The stability of the results was monitored over time. Five urine samples known to be negative for all drug categories and 24 patient samples confirmed positive for a total of 95 drugs and/or drug metabolites claimed to be detected by the device were tested. Adulterants and potential cross-reacting compounds were also evaluated. One false-positive result for benzodizepines was observed. One false-negative result for barbiturates was observed, but was resolved. Overall, the cups demonstrated excellent sensitivity, specificity, and diagnostic efficiency for all drugs represented.

Barbiturate detection in oral fluid, plasma, and urine.

BACKGROUND: Although current abuse of barbiturates is low compared with other classes of abused drugs, their narrow margin of safety, risk of dependence, and abuse liability remain a health concern. Limited information is available on the disposition of barbiturates in different biologic matrices. OBJECTIVE: The authors conducted a clinical study of the disposition of barbiturates in oral fluid, plasma, and urine after single-dose administration to healthy subjects. METHODS: Three parallel groups of 15 subjects were administered a single oral dose of one barbiturate: butalbital (50 mg), Phenobarbital (30 mg), or sodium secobarbital (100 mg). Subjects remained at the clinic for two confinement periods; the first was -1 to 36 hours postdose and again at 48 to 52 hours. Oral fluid specimens were collected by bilateral collection (Intercept; one on each side of the mouth simultaneously). Blood specimens were obtained by venipuncture and urine specimens were collected through separate collection pools of varying periods. Oral fluid specimens were analyzed for barbiturates by liquid chromatography-tandem mass spectroscopy with a limit of quantitation of 8 ng/mL. Plasma and urine specimens were analyzed by gas chromatography-mass spectroscopy with a limit of quantitation of 100 ng/mL. RESULTS: Barbiturate side effects included dizziness, drowsiness, and somnolence. All effects resolved spontaneously without medical intervention. The three barbiturates were detectable in oral fluid and plasma within 15 to 60 minutes of administration and in the first urine pooled collection at 2 hours. Butalbital and Phenobarbital remained detectable in all specimens through 48 to 52 hours, whereas secobarbital was frequently negative in the last collection. Oral fluid to plasma ratios appeared stable over the 1- to 48-hour collection period. CONCLUSION: This study demonstrated that single, oral therapeutic doses of butalbital, Phenobarbital, and secobarbital were excreted in readily detectable concentrations in oral fluid over a period of approximately 2 days. Oral fluid patterns of appearance and elimination were similar to that observed for plasma and urine.

Quantitation of amobarbital, butalbital, pentobarbital, phenobarbital, and secobarbital in urine, serum, and plasma using gas chromatography-mass spectrometry (GC-MS).

Barbiturates are central nervous system depressants with sedative and hypnotic properties. Some barbiturates, with longer half-lives, are used as anticonvulsants. Their mechanism of action includes activation of gamma-aminobutyric acid (GABA) mediated neuronal transmission inhibition. Clinically used barbiturates include amobarbital, butalbital, pentobarbital, phenobarbital, secobarbital, and thiopental. Besides their therapeutic use, barbiturates are commonly abused. Their analysis is useful for both clinical and forensic proposes. Gas chromatography mass spectrometry is a commonly used method for the analysis of barbiturates. In the method described here, barbiturates from serum, plasma, or urine are extracted using an acidic phosphate buffer and methylene chloride. Barbital is used as an internal standard. The organic extract is dried and reconstituted with mixture of trimethylanilinium hydroxide (TMAH) and ethylacetate. The extract is injected into a gas chromatogram mass spectrometer where it undergoes "flash methylation" in the hot injection port. Selective ion monitoring and relative retention times are used for the identification and quantitation of barbiturates.

Barbiturate intoxication in two dogs confirmed by toxicological urinalysis.

Two dogs were presented within 24 hours to the Department of Small Animal Medicine and Surgery at the University of Veterinary Medicine Hannover for investigation of the sudden onset of neurological abnormalities following a walk in the same park. One dog was observed ingesting a piece of meat. Analysis of urine by gas chromatography-mass spectrometry from each of the dogs identified the presence of barbiturates. Both dogs recovered with supportive treatment. This is the first report to describe the use of toxicological urinalysis with gas chromatography-mass spectrometry for the diagnosis of barbiturate intoxication in dogs.