David M. Andrenyak

4-Methylmethcathinone (Mephedrone): Neuropharmacological Effects of a Designer Stimulant of Abuse

The designer stimulant 4-methylmethcathinone (mephedrone) is among the most popular of the derivatives of the naturally occurring psychostimulant cathinone. Mephedrone has been readily available for legal purchase both online and in some stores and has been promoted by aggressive Web-based marketing. Its abuse in many countries, including the United States, is a serious public health concern. Owing largely to its recent emergence, there are no formal pharmacodynamic or pharmacokinetic studies of mephedrone. Accordingly, the purpose of this study was to evaluate effects of this agent in a rat model. Results revealed that, similar to methylenedioxymethamphetamine, methamphetamine, and methcathinone, repeated mephedrone injections (4× 10 or 25 mg/kg s.c. per injection, 2-h intervals, administered in a pattern used frequently to mimic psychostimulant “binge” treatment) cause a rapid decrease in striatal dopamine (DA) and hippocampal serotonin (5-hydroxytryptamine; 5HT) transporter function. Mephedrone also inhibited both synaptosomal DA and 5HT uptake. Like methylenedioxymethamphetamine, but unlike methamphetamine or methcathinone, repeated mephedrone administrations also caused persistent serotonergic, but not dopaminergic, deficits. However, mephedrone caused DA release from a striatal suspension approaching that of methamphetamine and was self-administered by rodents. A method was developed to assess mephedrone concentrations in rat brain and plasma, and mephedrone levels were determined 1 h after a binge treatment. These data demonstrate that mephedrone has a unique pharmacological profile with both abuse liability and neurotoxic potential.

Methamphetamine Self-Administration Causes Persistent Striatal Dopaminergic Alterations and Mitigates the Deficits Caused by a Subsequent Methamphetamine Exposure

Preclinical studies have demonstrated that repeated methamphetamine (METH) injections (referred to herein as a “binge” treatment) cause persistent dopaminergic deficits. A few studies have also examined the persistent neurochemical impact of METH self-administration in rats, but with variable results. These latter studies are important because: 1) they have relevance to the study of METH abuse; and 2) the effects of noncontingent METH treatment do not necessarily predict effects of contingent exposure. Accordingly, the present study investigated the impact of METH self-administration on dopaminergic neuronal function. Results revealed that self-administration of METH, given according to a regimen that produces brain METH levels comparable with those reported postmortem in human METH abusers (0.06 mg/infusion; 8-h sessions for 7 days), decreased striatal dopamine transporter (DAT) uptake and/or immunoreactivity as assessed 8 or 30 days after the last self-administration session. Increasing the METH dose per infusion did not exacerbate these deficits. These deficits were similar in magnitude to decreases in DAT densities reported in imaging studies of abstinent METH abusers. It is noteworthy that METH self-administration mitigated the persistent deficits in dopaminergic neuronal function, as well as the increases in glial fibrillary acidic protein immunoreactivity, caused by a subsequent binge METH exposure. This protection was independent of alterations in METH pharmacokinetics, but may have been attributable (at least in part) to a pretreatment-induced attenuation of binge-induced hyperthermia. Taken together, these results may provide insight into the neurochemical deficits reported in human METH abusers.

A comparison of ONTRAK TESTCUP, abuscreen ONTRAK, abuscreen ONLINE, and GC/MS urinalysis test results.

This study was designed to compare results obtained from two separate on-site drug testing kits (ONTRAK TESTCUP and Abuscreen ONTRAK) with those obtained from laboratory based immunoassay and GC/MS. Abuscreen ONLINE immunoassay was used to select 250 negative samples and 100 presumptive-positive samples each for cocaine/metabolites, opiates and cannabinoids. Presumptive-positive samples were selected if the immunoassay response was > or = 300 ng/mL for cocaine/metabolites (BZE), > or = 300 ng/mL for opiates or > or = 50 ng/mL for cannabinoids (THC-COOH). GC/MS was used to confirm that each selected sample contained > or = 150 ng/mL BZE, > or = 300 ng/mL morphine/codeine or > or = ng/mL THC-COOH. TESTCUP results had a 100% agreement with GC/MS and a > 99% agreement with ONLINE when testing negative samples. The agreement between TESTCUP and ONLINE results for samples containing opiates was 100%. Results of testing samples containing BZE with TESTCUP demonstrated a 98% agreement with both GC/MS and ONLINE. Both discrepant samples contained BZE at concentrations < or = 300 ng/mL. The least agreement between TESTCUP and ONLINE results was found when testing samples containing THC-COOH. The agreement with ONLINE and GC/MS was 92% and all discrepant samples had GC/MS determined THC-COOH concentrations less than 50 ng/mL. A 100% agreement was obtained between expected and recorded TESTCUP results for QC samples fortified to contained BZE, morphine or THC-COOH at concentrations within 120% of the screening cutoffs. ONTRAK had a 100% agreement with both GC/MS and ONLINE when testing negative samples and samples that contained opiates. ONTRAK had a 91% agreement with GC/MS and ONLINE for testing of samples that contained BZE. The least agreement between ONTRAK and ONLINE results was found when testing samples that contained THC-COOH. The agreement was 89%, however, all discrepant samples contained GC/MS concentrations of THC-COOH less that the 50 ng/mL cutoff. With ONTRAK, a 100% agreement was obtained between expected and recorded results QC samples that contained morphine or THC-COOH and a 97.7% agreement was obtained between expected and recorded results on QC samples that contained BZE.

Fate of Systemically Administered Cocaine in Nonhuman Primates Treated with the dAd5GNE Anticocaine Vaccine

Cocaine use disorders are mediated by the cocaine blockade of the dopamine transporter in the central nervous system (CNS). On the basis of the concept that these effects could be obviated if cocaine were prevented from reaching its cognate receptors in the CNS, we have developed an anticocaine vaccine, dAd5GNE, based on a cocaine analog covalently linked to capsid proteins of an E1(-)E3(-) serotype 5 adenovirus. While the vaccine effectively blocks systemically administered cocaine from reaching the brain by mediating sequestration of the cocaine in the blood, the fact that cocaine also has significant peripheral effects raises concerns that vaccination-mediated redistribution could lead to adverse effects in the visceral organs. The distribution of systemically administered cocaine at a weight-adjusted typical human dose was evaluated along with cocaine metabolites in both dAd5GNE-vaccinated and control nonhuman primates. dAd5GNE sequestration of cocaine to the blood not only prevented cocaine access to the CNS, but also limited access of both the drug and its metabolites to other cocaine-sensitive organs. The levels of cocaine in the blood of vaccinated animals rapidly decreased, suggesting that while the antibody limits access of the drug and its active metabolites to the brain and sensitive organs of the periphery, it does not prolong drug levels in the blood compartment. Gross and histopathology of major organs found no vaccine-mediated untoward effects. These results build on our earlier measures of efficacy and demonstrate that the dAd5GNE vaccine-mediated redistribution of administered cocaine is not likely to impact the vaccine safety profile.

Early opacification of silicone intraocular lenses: Laboratory analyses of 6 explants.

PURPOSE: To report laboratory analyses of 6 intraocular lenses (IOLs) explanted from patients who had visual disturbances caused by early postoperative opacification of the lens optic. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Six patients with 3‐piece silicone lenses presented with optic cloudiness as early as a few hours after implantation. The lenses were implanted in 4 locations in Brazil and in France. The lenses in Brazil were stored at the same location before implantation. Gross and microscopic analyses were performed (dry and hydrated states). One half of each specimen underwent gas chromatography/mass spectrometry (GC/MS) analysis and/or extraction by isopropyl alcohol or acetonitrile. One lens also underwent scanning electron microscopy (SEM) with energy dispersive x‐ray spectroscopy (EDS). The IOLs were examined for the presence of contaminants or deposits that could cause fast optic opacification. RESULTS: The IOLs showed a white optic discoloration in the hydrated state but became transparent on complete dehydration. Suspect exogenous chemical compounds were identified in GC/MS analyses; general classes included terpenes and ketones, typically found in industrial cleaning agents and fumigants. Surface analysis (SEM and EDS) did not show any significant deposits on the external surfaces and sagittal cut in 1 of the specimens. CONCLUSIONS: Most IOLs are enclosed in semipermeable packages to allow sterilization by ethylene oxide gas. During cleaning or disinfection of storage rooms, aerosolized solutions may introduce chemicals through the package and onto the IOLs. This may cause surface changes in the IOL, promoting opacification by water ingress in the aqueous environment. Cleaning and disinfection procedures of IOL storage areas should be monitored carefully.

Detection of pepper spray residues on fabrics using liquid chromatography-mass spectrometry

The analysis of trace evidence for the presence of biological and nonbiological residues is an integral part of many criminal and civil investigations and the use of pepper spray self-defense weaponry by the general public, criminals, and law enforcement agents is increasing. Therefore, the possibility that pepper spray residues may be present as forensic evidence at crime scenes or from civil disturbances becomes more likely. We have investigated the effects of storage and washing on the detection of pepper spray residues (i.e., capsaicinoids) on cotton, cotton-polyester blend, wool, and nylon fabrics. The concentrations of the capsaicinoid analogues on the fabrics decreased between 5 to 60% during six months of storage when compared with samples of each fabric type that were prepared and analyzed at the onset of the stability study (Time 0). The rate of disappearance of the capsaicinoids was analogue specific. Degradation of the capsaicinoids was independent of fabric type and temperature of storage. We also investigated the effects of washing the fabrics on the detection of capsaicinoids. Fabrics were washed with water, 1% detergent, 1% bleach, or 5%Spray and Wash™. Water was the least effective method of removing the capsaicinoids from the fabric and bleach the most effective. Retention of the capsaicinoids on the fabrics following washing was affected by fabric type as well as the chemical properties of the individual capsaicinoid analogues. The uses and limitations of capsaicinoid residue evidence as an indicator of exposure to pepper sprays or use of pepper sprays are discussed.

Application of programmable bio-nano-chip system for the quantitative detection of drugs of abuse in oral fluids

OBJECTIVE There is currently a gap in on-site drug of abuse monitoring. Current detection methods involve invasive sampling of blood and urine specimens, or collection of oral fluid, followed by qualitative screening tests using immunochromatographic cartridges. While remote laboratories then may provide confirmation and quantitative assessment of a presumptive positive, this instrumentation is expensive and decoupled from the initial sampling making the current drug-screening program inefficient and costly. The authors applied a noninvasive oral fluid sampling approach integrated with the in-development chip-based Programmable bio-nano-chip (p-BNC) platform for the detection of drugs of abuse. METHOD The p-BNC assay methodology was applied for the detection of tetrahydrocannabinol, morphine, amphetamine, methamphetamine, cocaine, methadone and benzodiazepines, initially using spiked buffered samples and, ultimately, using oral fluid specimen collected from consented volunteers. RESULTS Rapid (∼10min), sensitive detection (∼ng/mL) and quantitation of 12 drugs of abuse was demonstrated on the p-BNC platform. Furthermore, the system provided visibility to time-course of select drug and metabolite profiles in oral fluids; for the drug cocaine, three regions of slope were observed that, when combined with concentration measurements from this and prior impairment studies, information about cocaine-induced impairment may be revealed. CONCLUSIONS This chip-based p-BNC detection modality has significant potential to be used in the future by law enforcement officers for roadside drug testing and to serve a variety of other settings, including outpatient and inpatient drug rehabilitation centers, emergency rooms, prisons, schools, and in the workplace.

Lack of long-term changes in cocaine and monoamine concentrations in rat CNS following chronic administration of cocaine

In previous studies, we reported time-dependent and dose-dependent changes in the rat dopaminergic receptor system following chronic administration of cocaine. The aim of the present investigation was to monitor the concentration of monoamines (using HPLC-ECD) and cocaine (using GC-PCI/MS) in rat CNS following a dose schedule of 5, 10, 15, 20 and 25 mg/kg, i.p., b.i.d. for 21 days. 12 h after the last cocaine injection, cortical and striatal concentrations of monoamines and their metabolites were not significantly different in saline vs cocaine treated animals. In addition, the cocaine concentration in the brain regions examined did not change with the different doses used. Accumulation of a metabolite of cocaine (ecgonine methyl ester) was the only alteration found. These results indicate that alterations in the dopaminergic receptor system following chronic cocaine administration are not due to changes in neurotransmitter concentration or accumulation of cocaine in the brain.

Safety of Intravenous Methamphetamine Administration During Ibudilast Treatment

Background Methamphetamine dependence is a significant public health concern without any approved medications for treatment. We evaluated ibudilast, a nonselective phosphodiesterase inhibitor, to assess the safety and tolerability during intravenous methamphetamine administration. We conducted a randomized, double-blind, placebo-controlled, within-subjects crossover clinical trial. Methods Participants received ibudilast (20 mg twice daily followed by 50 mg twice daily) and placebo, with order determined by randomization, and then underwent intravenous methamphetamine challenges (15 and 30 mg). We monitored cardiovascular effects, methamphetamine pharmacokinetics, and reported adverse events. Results Ibudilast treatment had similar rates of adverse events compared with placebo, and there was no significant augmentation of cardiovascular effects of methamphetamine. Pharmacokinetic analysis revealed no clinically significant change in maximum concentration or half-life of methamphetamine with ibudilast. Conclusions Methamphetamine administration during ibudilast treatment was well tolerated without additive cardiovascular effects or serious adverse events, providing initial safety data to pursue ibudilasts effectiveness for the treatment of methamphetamine dependence.

Detection of Acetaminophen–Protein Adducts in Decedents with Suspected Opioid–Acetaminophen Combination Product Overdose†

Acetaminophen overdose is a leading cause of drug‐induced liver failure in the United States. Acetaminophen–protein adducts have been suggested as a biomarker of hepatotoxicity. The purpose of this study was to determine whether protein‐derived acetaminophen–protein adducts are quantifiable in postmortem samples. Heart blood, femoral blood, and liver tissue were collected at autopsy from 22 decedents suspected of opioid–acetaminophen overdose. Samples were assayed for protein‐derived acetaminophen–protein adducts, acetaminophen, and selected opioids found in combination products containing acetaminophen. Protein‐derived APAP‐CYS was detected in 17 of 22 decedents and was measurable in blood that was not degraded or hemolyzed. Heart blood concentrations ranged from 11 ng/mL (0.1 μM) to 7817 ng/mL (28.9 μM). Protein‐derived acetaminophen–protein adducts were detectable in liver tissue for 20 of 22 decedents. Liver histology was also performed for all decedents, and no evidence of centrilobular hepatic necrosis was observed.