Driving Impairment Cases Involving Etizolam and Flubromazolam.

This study describes 12 cases of drivers stopped for impaired driving, where a designer benzodiazepine was detected, specifically etizolam or flubromazolam. Etizolam was detected in three cases, with blood concentrations ranging from 40 to 330 ng/mL. Two of these cases had low concentrations of methamphetamine and/or amphetamine, and in the third case tetrahydrocannabinol (THC) was detected. Flubromazolam was detected in nine cases; in all cases, at least one other drug was detected, with THC being the most prevalent. The mean blood concentration of flubromazolam was 16.3 ng/mL and had a median concentration of 17.0 ng/mL, ranging from 7.0 to 31 ng/mL. The low concentrations of designer benzodiazepines that produce pharmacological effects may allow many of these drugs to go undetected using routine testing in laboratories; therefore, it is necessary to include these novel compounds within validated analytical methods to reduce the chance of reporting false negative results. The prevalence in which laboratories are detecting the presence of novel benzodiazepines in impaired drivers illustrates the increased threat to public safety. These case studies demonstrate the importance of investigating agencies and forensic laboratories to be vigilant in monitoring the emerging novel psychoactive substances in their region.

Metabolic profiling of the Uncaria hook alkaloid geissoschizine methyl ether in rat and human liver microsomes using high-performance liquid chromatography with tandem mass spectrometry.

Geissoschizine methyl ether (GM) is an indole alkaloid found in Uncaria hook, which is a galenical constituent of yokukansan, a traditional Japanese medicine. GM has been identified as the active component responsible for anti-aggressive effects. In this study, the metabolic profiling of GM in rat and human liver microsomes was investigated. Thirteen metabolites of GM were elucidated and identified using a high-performance liquid chromatography with tandem mass spectrometry method, and their molecular structures were proposed on the basis of the characteristics of their precursor ions, product ions, and chromatographic retention times. There were no differences in the metabolites between the rat and human liver microsomes. Among the 13 identified metabolites, there were two demethylation metabolites, one dehydrogenation metabolite, three methylation metabolites, three oxidation metabolites, two water-adduct metabolites, one di-demethylation metabolite, and one water-adduct metabolite followed by oxidation. The metabolic pathways of GM were proposed on the basis of this study. This study will be helpful in understanding the metabolic routes of GM and related Uncaria hook alkaloids, and provide useful information on the pharmacokinetics and pharmacodynamics. This is the first report that describes the separation and identification of GM metabolites in rat and human liver microsomes.

Interactions of phenothiazine drugs with bile salts: micellization and binding studies.

An evaluation of the interactions of phenothiazine tranquilizer drugs (promazine hydrochloride; PMZ and promethazine hydrochloride; PMT) with bile salts viz., sodium cholate (NaC) and sodium deoxycholate (NaDC) in aqueous medium, investigated through different physicochemical measurements is presented in this work. The mixed micellization behavior and surface properties of the phenothiazine-bile salt systems have been analyzed by conductivity and surface tension measurements. Application of different theoretical approaches to all the phenothiazine-bile salt mixtures shows a non-ideal behavior. Further, the spectroscopic techniques such as UV-visible and steady state fluorescence have been employed to study the binding of phenothiazines with bile salts. The stoichiometric ratios, binding constants (K), and free energy change (ΔG) for the phenothiazine-bile salt complexes were estimated from the Benesi-Hildebrand (B-H) double reciprocal plots obtained by using the changes in spectral intensities of phenothiazines on addition of bile salts. The results are discussed in the light of use of bile salts as promising drug delivery agents for phenothiazines and hence improve their bioavailabilty.

Benzodiazepines: sample preparation and HPLC methods for their determination in biological samples.

Benzodiazepines (BDZs) belong to a group of substances known for their sedative, antidepressive, muscle relaxant, tranquilizer, hypnotic and anticonvulsant properties. Their determination in biological fluids is essential in clinical assays as well as in forensics and toxicological studies. Researchers focus on the development of rapid, accurate, precise and sensitive methods for the determination of BDZs and their metabolites. A large number of analytical methods using different techniques have been reported, but none can be considered as the method of choice. BDZs are usually present at trace levels (microgram or nanogram per milliliter) in a complex biological matrix and the potentially interfering compounds must be isolated by various extraction techniques before analysis. An extended and comprehensive review is presented herein, focusing on sample preparation (pretreatment and extraction) and HPLC conditions applied by different authors. These methods enable bioanalysts to achieve detection limits down to 1-2 ng/ml using UV/diode array detection, readily available in most laboratories, and better than 1 ng/ml using electron capture detection, which is lower than that obtained using a nitrogen phosphorus detector. MS interfaced with electrospray ionization offered a similar sensitivity, while negative chemical ionization MS or sonic spray ionization MS provided sensitivity down to 0.1 ng/ml.

Induction of the metabolism of etizolam by carbamazepine in humans.

OBJECTIVE: To examine the effect of carbamazepine on the single oral dose pharmacokinetics of etizolam. METHODS: Eleven healthy male volunteers received carbamazepine 200 mg/day or placebo for 6 days in a double-blind, randomized, crossover manner, and on the sixth day they received a single oral 1-mg dose of etizolam. Blood samplings and evaluation of psychomotor function by the Digit Symbol Substitution Test and Stanford Sleepiness Scale were conducted up to 24 h after etizolam dosing. Plasma concentration of etizolam was measured using high-performance liquid chromatography. RESULTS: Carbamazepine treatment significantly decreased the peak plasma concentration (17.5+/-4.1 ng/ml versus 13.9+/-4.1 ng/ml; P<0.05), total area under the plasma concentration-time curve (194.8+/-88.9 ng h/ml versus 105.9+/-33.0 ng h/ml; P<0.001), and elimination half-life (11.1+/-4.6 h versus 6.8+/-2.8 h; P<0.01) of etizolam. No significant change was induced by carbamazepine in the two pharmacodynamic parameters. CONCLUSIONS: The present study suggests that carbamazepine induces the metabolism of etizolam.

[Assessment of CYP2D6 activity as a form of optimizing antidepressant therapy]. / Badanie aktywnosci CYP2D6 jako forma optymalizacji terapii lekami przeciwdepresyjnymi.

Cytochrome 2D6 catalyzes oxidation processes of many antidepressants (TCAs, SSRIs, maprotyline, mianserine, nefazodon, trazodon, venlafaxine). CYP2D6 is characterized by genetically determined polymorphism which may lead to serious clinical consequences. Based on CYP2D6 activity four phenotypes are distinguished: poor metabolism (PM), intermediate (IM), extensive (normal) EM and ultrarapid (UM). In case of PM and IM increased plasma concentration of a drug and adverse events or toxicity may appear. Decreased plasma level and lack of clinical effect may be connected with the ultrarapid phenotype. CYP2D6 activity may be assessed by phenotyping or genotyping . Model drugs such as sparteine, debrisoquine, dextromethorphan and metoprolol are used in the phenotyping method. Based on the metabolic ratio of model drug the phenotype status is established. Genotyping consists in an assessment of genotype i.e. an identification of alleles coding the CYP2D6 protein. The environmental factors may modify the CYP2D6 activity and have influence on phenotyping but not genotyping results. The knowledge of CYP2D6 phenotype is of special value when drugs characterized by a narrow therapeutic index are used and in polymedicated and older patients.

Biphasic kinetics of imipramine N-oxidation in rat brain microsomes.

Imipramine (IMI) N-oxidase activity in brain microsomes from rats of both sexes was determined by high performance liquid chromatography, and compared with the results in rat liver microsomes. Brain and liver microsomal IMI N-oxidation was sensitive to thermal inactivation and had an optimal pH at around 9.0. IMI N-oxidase activity (15.54 pmol/min/mg protein) in brain microsomes was about one-hundredth that of liver microsomes (2.08 nmol/min/mg protein) at a substrate concentration of 5 mM. IMI N-oxidase activities in both brain and liver microsomes displayed biphasic kinetics that associated a low Km-low Vmax element with a high Km-high Vmax component. Furthermore, a significant sex difference was observed in Vmax values (male>female) in both phases, but Km values were similar between male and female rats, resulting in a significant sex difference (male>female) in intrinsic clearance values (Vmax/Km) of the low-Km and the high-Km phases.

Determination of trace lithium in human erythrocytes by electrothermal atomic-absorption spectrometry with pyrocoated graphite tubes and integrated platform.

Electrothermal graphite-furnace atomic-absorption spectroscopy with pyrocoated graphite tubes, integrated platform and matrix modification was used to determine submicromolar concentrations of trace lithium in human red blood cells. Matrix-matched samples were used to establish calibration curves for concentrations up to 0.58 microM (addition-calibration method) with satisfactory linearity (r2 > 0.99) and intra- and inter-day variability (CV < 11.4%). The median concentration of trace lithium in the cells of 40 healthy Caucasian volunteers devoid of medical or psychiatric history was 0.23 microM (inter-quartile range 0.20-0.30). The levels of trace lithium in the red blood cells correlated (r2 = 0.83) with plasma concentrations (median 0.13 microM, inter-quartile range 0.11-0.19) measured in the same blood sample. Dietary factors (e.g. consumption of lithium-containing mineral water) affected both levels. The red blood cell/plasma lithium ratio had a median value of 1.57 (inter-quartile range 1.16-2.07), implying that trace lithium is accumulated in erythrocytes. This contrasts with most reports of red blood cell/plasma ratio, measured during therapeutic treatment with lithium, for which the average value is 0.5-0.8, albeit for much higher concentrations of lithium (approx. 500-800 microM). The proposed analytical method has the required sensitivity and accuracy for determination of trace lithium in red blood cells and makes it possible to perform epidemiological studies to assess human exposure to environmental lithium in diet and beverages, and inter-individual variations in trans-membrane and renal lithium kinetics at the submicromolar level.

[Genotoxic effects of metabolic derivatives of the new drug phosphabenzide]. / Genotoksicheskie éffekty metabolicheskikh proizvodnykh novogo lekarstvennogo preparata fosfabenzida.

Genotoxic action of four possible metabolites of the new tranquilizer phosphabenzide (acetylphosphabenzide, diphenylphosphinylacetic acid, phosphabenzide hydrazone with pyruvic acid, bis-1,2-(diphenylphosphinylacetyl)hydrazine) has been studied. These metabolites belong to slightly toxic phosphororganic compounds. The Ames Salmonella/microsomes tests performed on strains TA100 and TA98 showed that of these compounds only acetylphosphabenzide possessed mutagenic action. Metabolic activation of liver microsomes decreased the mutagenic effect. The mechanism of action of acetylphosphabenzide is likely to involve the formation of acetylhydrazine, capable of producing active electrophiles attacking DNA.

Potential interference of cyclobenzaprine and norcyclobenzaprine with HPLC measurement of amitriptyline and nortriptyline: resolution by GC-MS analysis.

Cyclobenzaprine and its major metabolite, norcyclobenzaprine, differ from amitriptyline and nortriptyline only by the presence of a double bond in the cycloheptane ring. Three patients developed sufficient levels of cyclobenzaprine and norcyclobenzaprine because of either rapid or long-term ingestion of cyclobenzaprine to cause positive interferences in both a Syva EMIT assay and a high-performance liquid chromatographic (HPLC) assay for identification and quantitation of tricyclic antidepressants in serum. Cyclobenzaprine coeluted with amitriptyline, and norcyclobenzaprine eluted slightly earlier than, but was poorly resolved from, nortriptyline in this HPLC assay. We found that cyclobenzaprine could be distinguished from amitriptyline and that norcyclobenzaprine could be distinguished from nortriptyline on the basis of gas chromatographic retention times upon gas chromatographic-mass spectrometric analyses after derivatization with trifluoroacetic anhydride. The compounds were also distinguishable by mass spectrometric criteria.

Behavioural and biochemical evidence of the interaction of the putative antipsychotic agent, BMY 14802 with the 5-HT1A receptor.

The behavioural and biochemical profile of the sigma ligand and putative antipsychotic agent, BMY 14802 (alpha-(4-fluorophenyl)-4-(5-fluoro-2- pyrimidinyl)-1-piperazine butanol) has been determined in the mouse and rat. In mice, pretreatment with BMY 14802 attenuated both amphetamine-induced hyperactivity and conditioned avoidance responding, consistent with its previously reported antipsychotic potential. In common with 5-HT1A receptor agonists or partial agonists, BMY 14802 induced (a) a dose-dependent hypothermia in mice; (b) aspects of the 5-HT behavioural syndrome in rats, (c) antagonised mescaline-induced head twitches in mice and (d) generalised to the 8-hydroxy-2-(di-n-propylamino)tetralin discriminative stimulus over the dose range of 3-15 mg/kg. BMY 14802 had appreciable affinity for the 5-HT1A receptor (pIC50 = 6.7 compared to 7.3 for sigma binding) and antagonised forskolin-stimulated adenylate cyclase activity with a pEC50 of 6.2, consistent with an agonist action at this receptor. The results support the involvement of 5-HT1A receptors, but not the sigma binding site, in the behavioural profile of BMY 14802.

Hydrolysis of haloperidol decanoate in vitro by cultured cells.

[14C]Haloperidol decanoate was hydrolysed by partially purified carboxylesterase but not in plasma, blood, lymph and lymphatic liquid. These fluids inhibited the enzyme-mediated hydrolysis of the ester. Within the same incubation period as above, the ester was found hydrolysed to various extents in cell cultures of isolated rat liver cells, of human and rat lymphocytes and of established cell lines (BGM cells, WI-38 cells and L6 cells). Thus, the hydrolysis of the ester was demonstrated in vitro with use of viable cell cultures instead of enzyme preparation. From the time course study on the metabolism of haloperidol decanoate in cell cultures, it was concluded that haloperidol decanoate was first concentrated in the cells and hydrolysed to haloperidol. Based on these results, the metabolic sequences in vivo leading to the formation of active principle haloperidol after intramuscular administration of its decanoate were discussed.

Tranquilizers and sedative/hypnotics: appropriate use in the elderly.

In treating the elderly patient, it is generally true that the fewer pharmacologic agents needed, the less the potential for drug interactions and puzzling toxic reactions. Nevertheless, sedative/hypnotics and anxiolytic drugs (mostly the benzodiazepines) are safe and effective therapy for the older patient, when the appropriate indications and dosages are observed. On the other hand, the toxic potential of nonbenzodiazepines (eg, barbiturates and pseudobarbiturates) and of even the relatively safe alternatives (eg, chloral hydrate, diphenhydramine, and hydroxyzine) render them less useful for the treatment of sleep disturbances. A final nonpharmacologic note: the physician should bear in mind that a balanced medical and psychological approach to sleep disturbance and anxiety in the elderly often yields success. This includes establishing a bedtime routine and using behavioral techniques, such as relaxation training, biofeedback, and even self-hypnosis. Patients can often be referred to a center where these approaches are employed.

Halopemide, a new psychotropic agent. Cerebral distribution and receptor interactions.

Halopemide is a new psychotropic agent, a structural analogue of the neuroleptics of the butyrophenone type but with different pharmacological and clinical properties. Preliminary clinical findings indicate that halopemide lacks the ability to induce parkinsonism and may be an effective drug in the treatment of psychosis characterized by autism, emotional withdrawal or apathy. Its pharmacological effects at a molecular level in comparison to structurally related neuroleptics and putative metabolites are reviewed.

Tranquilizers, analgetics and antidepressants in patients treated with hemodialysis.

Tranquilizers, analgetics and antidepressants are applied in different ranges in the treatment of patients on hemodialysis. Due to many different pharmacokinetic properties, no perfect rules for dosage in acute or chronic hemodialysis exist. Adequate applicable drugs without adaptation disregarding different states of renal failure are such with predominate hepatic metabolism and elimination or with inactive metabolites. In the management of acute renal failure, usually in connection with multiple organic disorders, a nonschematic, individually adapted therapy is indicated. In some substances, therapy can be determined by control of plasma concentration levels, in other drugs dosage is possible exclusively according to clinical effects. Substances with side effects on coagulation or acid-base equilibrium should be avoided. It is recommendable to get well acquainted with one substance out of each group in order to avoid polypragmasy.

[Clinical pharmacokinetics of mebikar]. / Klinicheskaia farmakokinetika mebikara.

Twenty-two patients admitted to the narcological clinic of an industrial enterprise were examined for the clinical effect and pharmacokinetic parameters after intake of a single dose of a Soviet psychotropic drug mebicar. The clinical status was assessed by means of psychometric mapping and concurrent recording of the EEG. The correlation of the pharmacodynamic and pharmacokinetic data can be used for the choice of minimal effective concentrations applied in further calculations of individual dosage regimens.

Analysis of propionylpromazine and its metabolites in horse urine.

The metabolism of propionylpromazine in the horse was studied. Although propionylpromazine is not currently approved or recommended for use in horses, it has been used illegally to alter their performance. Propionylpromazine hydrochloride was administered intramuscularly at clinical and subclinical doses. Three metabolites were detected in urine. The major metabolite was identified as 2-(1-hydroxypropyl) promazine sulfoxide. The detection of this metabolite in routine drug testing has been described.