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 ibudilast's effectiveness for the treatment of methamphetamine dependence.

Age-related differences in the disposition of nicotine and metabolites in rat brain and plasma.

INTRODUCTION: Studies have evaluated the behavioral and neurochemical impact of nicotine administration in rodents. However, the distribution of nicotine and metabolites in rat brain and plasma as a function of age has not been investigated. This is a significant issue because human adolescents have a greater risk for developing nicotine addiction than adults, and reasons underlying this observation have not been fully determined. Thus, in this present study, we evaluated the impact of the transition from adolescence (postnatal day [PND 40]) to adulthood (PND 90) on nicotine distribution in rats. METHODS: PND 40, 60, and 90 rats received a single injection of (-) nicotine (0.8 mg/kg, subcutaneously). Liquid chromatography tandem-mass spectrometry was used to measure concentration of nicotine and metabolites in selected biological matrices. RESULTS: Nicotine, cotinine, and nornicotine were detected in rat striata and frontal cortex 30 min, 1 hr, 2 hr, and 4 hr after a single administration. These and several additional metabolites (nicotine-1'-oxide, cotinine-N-oxide, norcotinine, and trans-3'-hydroxycotinine) were also detected in plasma at these same timepoints. The mean concentration of nicotine in brain and plasma was lower in PND 40 versus PND 90 rats. In contrast, the mean concentration of nornicotine was higher in the plasma and brain of PND 40 versus PND 90 rats. CONCLUSIONS: Nicotine and metabolite distribution differs between adolescent and adult rats. These data suggest that adolescent rats metabolize nicotine to some metabolites faster than adult rats. Further studies are needed to investigate the potential correlation between age, drug distribution, and nicotine addiction.

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.

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.

Analysis for Alpha-Pyrrolidinovalerophenone and Its 2-Oxo-PVP Metabolite in Plasma by Liquid Chromatography-Tandem Mass Spectrometry.

Alpha-pyrrolidinovalerophenone (alpha-PVP), a novel psychoactive substance, has widespread recreational use. This with interest in its pharmacological effects creates a need for methods that measure alpha-PVP concentrations. We therefore developed a LC-MS/MS method that can quantitate alpha-PVP and 2-oxo-PVP in rat plasma using a 0.1-mL sample volume. Addition of internal standards (2.5 ng/mL alpha-PVP-d8/2-oxo-PVP-d6) was followed by liquid-liquid extraction with 1-chlorobutane:acetonitrile (4:1), evaporation and reconstitution with 0.1% formic acid. Extracts were analyzed by LC-MS/MS using an Agilent 1100 HPLC and a Thermo Scientific TSQ Quantum Access MS/MS, with a YMC ODS-AQ, 50 mm × 2 mm, 3 µm column. The mobile phase was 0.1% formic acid:acetonitrile gradient at a 0.2-mL/minute flow rate with positive ion electrospray. SRM was used for the analysis with transitions: alpha-PVP, 232 â†’ 91; alpha-PVP-d8, 240 â†’ 91; 2-oxo-PVP, 246 â†’ 91; 2-oxo-PVP-d6, 252 â†’ 91. Alpha-PVP and 2-oxo-PVP eluted at 6.4 and 8.9 min. Calibrators range from 0.25 to 500 ng/mL. Accuracy and precision evaluated quality control samples prepared at 0.75, 10 and 400 ng/mL. The intra-assay evaluation also included the 0.25-ng/mL LOQs prepared in six different blank plasma sources. The intra-assay accuracy ranged from 88.9 to 117.8% of the target, and the intra-assay precision ranged from 0.9 to 16.0%. The inter-assay accuracy ranged from 98.7 to 110.7% of the target, and the inter-assay precision ranged from 4.5 to 12.0%. Extraction recovery was at least 52% for alpha-PVP and 67% for 2-oxo-PVP. Ionization recoveries were at least 64% for alpha-PVP and 82% for 2-oxo-PVP. These losses did not adversely affect assay performance. Alpha-PVP and 2-oxo-PVP controls were stable at room temperature for up to 24 h and frozen for at least 36 days. Alpha-PVP and 2-oxo-PVP were also stable in processed samples (extracts) stored at room temperature for at least 24 days. The procedure was used to analyze rat plasma samples from a pharmacokinetic study.

A validated method for the detection of Delta 9-tetrahydrocannabinol and 11-nor-9-carboxy- Delta 9-tetrahydrocannabinol in oral fluid samples by liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry.

A quantitative liquid chromatography-electrospray ionization-quadrupole-time-of-flight (TOF) mass spectrometry (MS) method for simultaneous determination of Delta(9)-tetrahydrocannabinol (THC) and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH) in oral fluid samples was developed and fully validated. The analytes were isolated from the oral fluid by classic liquid-liquid extraction. The two compounds were separated in 9.5 min with a total analysis time of 19 min. The linear dynamic range was established from 0.1 to 100 ng/mL for THC and 0.5-100 ng/mL for the THC-COOH. The method had a good intra- and interassay accuracy and precision at each measured concentration. No matrix effects were observed for the analytes or the labeled internal standards. Accurate mass measurement was achieved to +/- 5 ppm. The sensitivity of the method results from a combination of unique chromatographic retention time, the use of MS-MS, and the "exact mass" measurement of the target ions by a TOF analysis. The method was successfully applied to two types of oral fluid samples. One type was collected from roadside driving-under-the-influence studies. The second was used to assess the recovery of the THC from an oral fluid collection device under laboratory conditions. Although the use of the TOF MS in the forensic and toxicology fields is not as widespread as the triple-quadrupole technology, it offers some significant analytical advantages that are demonstrated by this method.

Determination of ∆-9-Tetrahydrocannabinol (THC), 11-hydroxy-THC, 11-nor-9-carboxy-THC and Cannabidiol in Human Plasma using Gas Chromatography-Tandem Mass Spectrometry.

Two marijuana compounds of particular medical interest are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). A gas chromatography-tandem mass spectrometry (GC-MS-MS) method was developed to test for CBD, THC, hydroxy-THC (OH-THC) and carboxy-THC (COOH-THC) in human plasma. Calibrators (THC and OH-THC, 0.1 to 100; CBD, 0.25 to 100; COOH-THC, 0.5-500 ng/mL) and controls (0.3, 5 and 80 ng/mL, except COOH-THC at 1.5, 25 and 400 ng/mL) were prepared in blank matrix. Deuterated (d3) internal standards were added to 1-mL samples. Preparation involved acetonitrile precipitation, liquid-liquid extraction (hexane:ethyl acetate, 9:1), and MSTFA derivatization. An Agilent 7890 A GC was interfaced with an Agilent 7000 MS Triple Quadrupole. Selected reaction monitoring was employed. Blood samples were provided from a marijuana smoking study (two participants) and a CBD ingestion study (eight participants). Three analytes with the same transitions (THC, OH-THC and COOH-THC) were chromatographically separated. Matrix selectivity studies showed endogenous chromatographic peak area ratios (PAR) at the analyte retention times were <20% of the analyte limit of quantitation PAR. The intra-assay accuracy ranged from 83.5% to 118% of target and the intra-run imprecision ranged from 2.0% to 19.1%. The inter-assay accuracy ranged from 90.3% to 104% of target and the inter-run imprecision ranged from 6.5% to 12.0%. Stability was established for 25 hours at room temperature, 207 days at -20°C, after three freeze-thaw cycles and for 26 days for rederivatized processed samples. After smoking marijuana predictable concentrations of THC, OH-THC and COOH-THC were seen; low concentrations of CBD were detected at early time points. In moderate users who had not smoked for at least 9 hours before ingesting an 800 mg oral dose of CBD, the method was sensitive enough to follow residual concentrations of THC and OH-THC; sustained COOH-THC concentrations over 50 ng/mL validated its higher analytical range.

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.

Recovery of drugs of abuse from the Immunalysis Quantisal oral fluid collection device.

Drug recovery from a new oral fluid collection device was assessed. The evaluation was performed in vitro at three physiologically relevant concentrations for the following substances: amphetamine, methamphetamine, morphine, codeine, cocaine, benzoylecgonine, methadone, oxazepam, and Delta(9)-tetrahydrocannabinol (THC). Drug-free and drug-fortified controls were prepared and their concentration verified by liquid chromatography-tandem mass spectrometry. Aliquots of the controls were then "collected" with the device (n=3) using the manufacturer's recommended procedure. Collected samples were stored for 12 h to simulate shipping before analysis. Fresh, non-"collected" aliquots of each pool (n=3) were concurrently analyzed. The drug recoveries from the Quantisal were expressed as a mean percentage of the concurrently analyzed aliquots that were not subjected to device collection. Recoveries for oxazepam exceeded 97%, for amphetamine and methamphetamine exceeded 93%, and for opioids all exceeded 91%. The recoveries of cocaine were >91% and >82% for its polar metabolite, benzoylecgonine. Especially noteworthy was the recovery of THC from the Quantisal collector (81.3-91.4%). When compared with recoveries reported from other collection devices, the Quantisal was clearly superior.

A comparative evaluation of the instant-view 5-panel test card with OnTrak TesTcup Pro 5: comparison with gas chromatography-mass spectrometry.

This study compared the ability of two on-site testing devices, Instant-View Test Card and OnTrak TesTcup Pro 5, to discriminate negative from positive urine samples for cannabinoids, cocaine metabolite, opiates, amphetamines, and benzodiazepines. The on-site devices were evaluated in a precision study with fortified urine samples and in a clinical study with samples submitted for forensic urine drug testing. For precision, seven stocks were prepared per device. Each stock had all five analytes added in a random fashion at 0, 25, 50, 75, 125, 150, or 175% of cutoff. Ten aliquots per stock were assigned random numbers and analyzed by two individuals. The respective accuracies (defined as "% below cutoff samples that were negative + % above cutoff samples that were positive") for Instant-View Test Card and TesTcup were 74.3 and 87.1 for amphetamines; 82.1 and 90.7 for benzoylecgonine; 88.6 and 90.7 for benzodiazepines; 83.6 and 94.3 for morphine; 82.1 and 87.9 for cannabinoids; and 82.1 and 90.1% overall. In contrast to the on-site testing devices, instrumental testing with OnLine reagents had perfect precision. For the clinical study, submitted samples that had reached their disposal date were rescreened for the five drug groups. Fifty that had absorbance changes near the negative control for all five drug groups were selected as "negatives"; 240 samples with positive or multi-positive results (some between the 75% control and cutoff) and confirmed by GC-MS were chosen as "positives" (at least 45 per drug group). The non-positive drug groups in these samples added 150 additional presumptively negatives per drug group. Samples were assigned random numbers, and two individuals tested each sample. The respective accuracies in respect to GC-MS results for Instant-View Test Card and TesTcup were 95.8 and 91.7 for amphetamines; 100 and 100 for benzoylecgonine; 96.7 and 96.5 for benzodiazepines; 98.8 and 99.2 for opiates; 94.4 and 95.0 for cannabinoids; and 97.1 and 96.5% overall. The clinical study revealed that the Instant-View Test Card had low cross-reactivity (i.e., false negatives) for samples with amphetamine only and oxycodone. TesTcup had low cross-reactivity for samples with amphetamine only and hydrocodone and/or hydromorphone; it also had more cross-reactivity towards (i.e., false positives) sympathomimetic amines. In summary, the Instant-View Test Card was less precise than the TesTcup at or near the cutoff; with clinical samples, however, the percent accuracies of the two devices were similar.

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.

Determination of riboflavin by high-performance liquid chromatography with riboflavin-depleted urine as calibration and control matrix.

A simple method, exposure to natural-light, was developed to remove riboflavin from urine to enhance its use as the biological matrix for the preparation of calibration and control samples. Riboflavin-depleted urine containing less than 1 ng/ml of riboflavin was used to validate a high-performance liquid chromatography with fluorescence detection method for the determination of urinary riboflavin. The linearity of the assay (r2=0.999) was acceptable over the range of 10-5000 ng/ml. The intra-assay and inter-assay CVs were 3.3% and 9%, respectively. Subsequent stability studies found that urine riboflavin was stable for up to 6 months at 4 or -20 degrees C.

Determination of nalmefene by high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry.

Nalmefene is an opioid antagonist used in the treatment of alcoholism and opioid overdose. A highly sensitive method was developed to measure nalmefene in human and rabbit plasma and rabbit serum. Nalbuphine was used as internal standard. Liquid-liquid extraction was applied using n-butyl chloride/acetonitrile (4:1). High-performance liquid chromatography interfaced by electrospray ionization to a tandem mass spectrometer was used for quantitation. Primary validation experiments were conducted using human plasma then it was cross-validated in rabbit plasma and rabbit serum. Specificity (peak-area ratio of blank plasma or serum to its internal standard as percent of peak-area ratio of blank plasma or serum fortified with 0.1 ng/mL nalmefene to its internal standard) ranged from 2.09 to 5.29 with a mean of 3.21% for human plasma and from 4.08 to 6.63 with a mean of 5.55% for rabbit plasma and from 2.47 to 6.17 with a mean of 3.62% for rabbit serum. The mean recovery for nalmefene was 80% in human plasma. The calibration range was from 0.1 to 100 ng/mL. Intrarun accuracy of the lower limit of quantitation (0.1 ng/mL) in all matrices was within 18.0% of target with intrarun precision within 13.6%. At 0.3, 35, and 75 ng/mL, the intrarun accuracy in all matrices was within 11.9% of target with intrarun precision within 6.6%. The inter-run accuracy in human plasma was within 8.0% of target with inter-run precision within 6.6%. Nalmefene was stable in human and rabbit plasma and rabbit serum for up to 24 h at room temperature and in human plasma after three freeze-thaw cycles. Following intravenous injection of 5 mg/kg nalmefene to rabbits, the mean area under curve for 0 to 24 h was 1116 (ng)(mL)(-1)(h), and the mean plasma clearance was 67.9 (mL)(min)(-1)(kg)(-1).

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.

Stability of plasma gamma-hydroxybutyrate determined by gas chromatography-positive ion chemical ionization-mass spectrometry.

An effective method for the determination of gamma-hydroxybutyric acid (GHB) in human plasma is described that utilizes a simple liquid-liquid extraction procedure and gas chromatography-positive ion chemical ionization-mass spectrometry (GC-PCI-MS). The method has been used to study the stability of plasma GHB under several storage conditions. Following the extraction with acetonitrile, GHB and deuterated GHB (GHB-d(6)) were derivatized with N,O-bis[trimethylsilyl] trifluoroacetamide (BSFTA). After the separation on a capillary GC column, the derivatives were ionized with ammonia reagent gas and analyzed by MS. The lower limit of quantitation in 100 microL of plasma was 2.5 microg/mL, over a range from 2.5 to 250 microg/mL. The coefficients of variation did not exceed 3.9% and the mean measured concentrations did not deviate more than 8% from the target for both intra- and interassay precision and accuracy. Plasma GHB was found to be stable at -20 degrees C for up to 9 months, at room temperature for 48 h, and after 3 freeze/thaw cycles. It was also found to be stable in processed samples stored at room temperature for 5 days and for 15 days at -20 degrees C.

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.