Karl B. Scheidweiler

Effects of Dose and Route of Administration on Pharmacokinetics of (±)-3,4-Methylenedioxymethamphetamine in the Rat

Based on animal data, there is speculation that (±)-3,4-methylenedioxymethamphetamine (MDMA) is neurotoxic to humans. Extrapolation of MDMA findings from animals to humans requires assessment of pharmacokinetics in various species, and low-dose administration data from rats are lacking. In this study, we examine MDMA pharmacokinetics in rats given low (2 mg/kg) and high (10 mg/kg) doses of racemic MDMA via intraperitoneal, subcutaneous, and oral routes. Repeated blood specimens were collected from venous catheters, and plasma was assayed for MDMA and its metabolites, 4-hydroxy-3-methoxymethamphetamine (HMMA) and 3,4-methylenedioxyamphetamine (MDA), by gas chromatography-mass spectrometry. After 2 mg/kg, maximum MDMA concentrations (Cmax) were ∼200 ng/ml for intraperitoneal and subcutaneous routes, but less for the oral route. MDMA plasma half-lives were <1 h for low-dose groups, whereas HMMA and MDA half-lives were >2 h. After 10 mg/kg, MDMA areas under the curve (AUCs) were 21-fold (intraperitoneal), 10-fold (subcutaneous), and 36-fold (oral) greater than those at 2 mg/kg. In contrast, HMMA AUC values in high-dose groups were <3-fold above those at 2 mg/kg. Several new findings emerge from this report of low-dose MDMA pharmacokinetics in rats. First, 2 mg/kg MDMA in rats can produce MDMA Cmax values similar to those in humans, perhaps explaining why both species discriminate 1.5 mg/kg MDMA in laboratory paradigms. Second, our data provide additional support for nonlinear kinetics of MDMA in rats, and, analogous to humans, this phenomenon appears to involve impaired drug metabolism. Finally, given key similarities between MDMA pharmacokinetics in rats and humans, data from rats may be clinically relevant when appropriate dosing conditions are used.

Comparison of the Ti-knot Device and Hem-o-lok Clips with Other Devices Commonly Used for Laparoscopic Renal-Artery Ligation

BACKGROUND AND PURPOSE New devices such as the Ti-knot and Hem-o-lok clips have been developed for laparoscopic surgical applications. We compared the effectiveness of Ti-knot TK5 (LSI Solutions), Hem-o-lok MLK clips (Weck Closure), Ligaclip 5-mm titanium clips (Ethicon), and Endopath vascular staples (35 mm long, 12.3 mm wide) (Ethicon). MATERIALS AND METHODS Renal artery segments from 5 to 6 mm in diameter were harvested from fresh porcine kidneys. One end of the vessel was intubated with a 25-gauge ball-tipped needle and fastened with two silk ties. The other end was occluded with one of the test devices. Saline was infused into each arterial segment at 3 mL/min with the maximum pump pressure at 800 mm Hg. The maximum pressure with leakage was recorded. Each of the five test devices was tested eight times on a rotating basis. Saline infusion was stopped when the maximum pump pressure was reached or when leakage was observed. RESULTS All Ti-knot devices, Hem-o-lok clips, titanium metal clips, and standard hand ties tolerated pressures >800 mm Hg with no leakage, but 4 of the 8 vascular staple lines (50%) leaked before this maximum pump pressure was reached. For those that leaked, the mean leak pressure was 273 mm Hg (range 237-322 mm Hg). CONCLUSIONS All devices tested are capable of occluding renal arteries under physiologic conditions. Ti-knot devices and Hem-o-lok clips occluded renal arteries to pressures that exceeded 800 mm Hg. They are equivalent to hand ties under supraphysiologic conditions.

Assessment of murine bladder permeability with fluorescein: validation with cyclophosphamide and protamine

Abstract Objectives. Bladder hyperpermeability should result in elevated blood levels of intravesically administered agents. Reabsorption from a hyperpermeable bladder should result in prolonged urinary excretion of an agent after parenteral administration. To test these hypotheses, urinary clearance and plasma levels of sodium fluorescein (NaF) were measured in mice before and during cyclophosphamide (CYP) and protamine-induced hemorrhagic cystitis. Methods. To measure the plasma uptake of NaF from the bladder, 10 mg/mL NaF was instilled, either by catheter or retrograde urethral infusion, 15 minutes before retro-orbital or ventricular sampling. The plasma levels were measured 24 hours and 14 days after exposure to CYP 300 mg/kg or 15 minutes after instillation of protamine 10 mg/mL. Hourly urine concentrations were measured immediately after intraperitoneal administration of 10 mg/kg NaF. Pretreatment samples were compared with those obtained 24 hours after intraperitoneal administration of 300 mg/kg CYP. Results. Urinary NaF excretion was delayed in CYP-exposed mice. A bi-exponential model provided an appropriate fit of the data, both before and after CYP administration. The plasma levels of NaF were significantly elevated at 24 hours and 14 days after CYP exposure when sampled by ventricular nick or retro-orbitally. The median concentration of fluorescein in the protamine-treated mice was significantly higher than in the control mice. Conclusions. Fluorescein can be used to measure alterations in bladder permeability after bladder mucosal injury in mice. Urinary excretion of NaF is a bi-exponential process that is delayed after bladder mucosal injury, presumably because of increased mucosal permeability and resorption from the urine into the bloodstream.

Relative performance of common biochemical indicators in detecting cigarette smoking

AIMS Many cities have banned indoor smoking in public places. Thus, an updated recommendation for a breath carbon monoxide (CO) cut-off is needed that optimally determines smoking status. We evaluated and compared the performance of breath CO and semiquantitative cotinine immunoassay test strips (urine and saliva NicAlert®) alone and in combination. DESIGN Cross-sectional study. SETTING Urban drug addiction research and treatment facility. PARTICIPANTS Ninety non-treatment-seeking smokers and 82 non-smokers. MEASUREMENTS Participants completed smoking histories and provided breath CO, urine and saliva specimens. Urine and saliva specimens were assayed for cotinine by NicAlert® and liquid chromatography-tandem mass spectrometry (LCMSMS). FINDINGS An optimal breath CO cut-off was established using self-report and LCMSMS analysis of cotinine, an objective indicator, as reference measures. Performance of smoking indicators and combinations were compared to the reference measures. Breath CO ≥5 parts per million (p.p.m.) optimally discriminated smokers from non-smokers. Saliva NicAlert® performance was less effective than the other indicators. CONCLUSIONS In surveys of smokers and non-smokers in areas with strong smoke-free laws, the breath carbon monoxide cut-off that discriminates most effectively appears to be ≥5 p.p.m. rather than the ≥10 p.p.m. cut-off often used. These findings may not generalize to clinical trials, regions with different carbon monoxide pollution levels or areas with less stringent smoke-free laws.

Metabolism of RCS-8, a synthetic cannabinoid with cyclohexyl structure, in human hepatocytes by high-resolution MS.

BACKGROUND Since 2008, synthetic cannabinoids are major new designer drugs of abuse. They are extensively metabolized and excreted in urine, but limited human metabolism data are available. As there are no reports on the metabolism of RCS-8, a scheduled phenylacetylindole synthetic cannabinoid with an N-cyclohexylethyl moiety, we investigated metabolism of this new designer drug by human hepatocytes and high resolution MS. METHODS After human hepatocyte incubation with RCS-8, samples were analyzed on a TripleTOF 5600+ mass spectrometer with time-of-flight survey scan and information-dependent acquisition triggered product ion scans. Data mining of the accurate mass full scan and product ion spectra employed different data processing algorithms. RESULTS & CONCLUSION More than 20 RCS-8 metabolites were identified, products of oxidation, demethylation, and glucuronidation. Major metabolites and targets for analytical methods were hydroxyphenyl RCS-8 glucuronide, a variety of hydroxycyclohexyl-hydroxyphenyl RCS-8 glucuronides, hydroxyphenyl RCS-8, as well as the demethyl-hydroxycyclohexyl RCS-8 glucuronide.

Urinary prevalence, metabolite detection rates, temporal patterns and evaluation of suitable LC-MS/MS targets to document synthetic cannabinoid intake in US military urine specimens.

Abstract Background: Identifying synthetic cannabinoid designer drug abuse challenges toxicologists and drug testing programs. The best analytical approach for reliably documenting intake of emerging synthetic cannabinoids is unknown. Primarily metabolites are found in urine, but optimal metabolite targets remain unknown, and definitive identification is complicated by converging metabolic pathways. Methods: We screened 20,017 US military urine specimens collected from service members worldwide for synthetic cannabinoids between July 2011 and June 2012. We confirmed 1432 presumptive positive and 1069 presumptive negative specimens by qualitative liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis including 29 biomarkers for JWH-018, JWH-073, JWH-081, JWH-122, JWH-200, JWH-210, JWH-250, RCS-4, AM2201 and MAM2201. Specimen preparation included enzyme hydrolysis and acetonitrile precipitation prior to LC-MS/MS analysis. We evaluated individual synthetic cannabinoid metabolite detection rates, prevalence, temporal patterns and suitable targets for analytical procedures. Results: Prevalence was 1.4% with 290 confirmed positive specimens, 92% JWH-018, 54% AM2201 and 39% JWH-122 metabolites. JWH-073, JWH-210 and JWH-250 also were identified in 37%, 4% and 8% of specimens, respectively. The United States Army Criminal Investigation Command seizure pattern for synthetic cannabinoid compounds matched our urine specimen results over the time frame of the study. Apart from one exception (AM2201), no parent compounds were observed. Conclusions: Hydroxyalkyl metabolites accounted for most confirmed positive tests, and in many cases, two metabolites were identified, increasing confidence in the results, and improving detection rates. These data also emphasize the need for new designer drug metabolism studies to provide relevant targets for synthetic cannabinoid identification.

MDMA and metabolite disposition in expectorated oral fluid after controlled oral MDMA administration.

Introduction: The use of 3,4-methylenedioxymethamphetamine (MDMA) is increasing, enhancing the need for its detection in clinical, workplace, pain management, and driving under the influence of drugs testing programs. Oral fluid is an important alternative matrix for drug testing, but little is known about MDMA detection windows in oral fluid. Aims: The aim was to characterize MDMA and metabolite disposition in expectorated oral fluid after controlled MDMA administration. Methods: Placebo, low (1.0 mg/kg), and high (1.6 mg/kg) oral MDMA doses were given double-blind in random order in separate sessions to 29 healthy adults with histories of MDMA use. One thousand two hundred eighty-six expectorated oral fluid specimens collected up to 7 days after dosing were analyzed for MDMA, 3,4-methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxymethamphetamine (HMMA), and 4-hydroxy-3-methoxyamphetamine (HMA) by gas chromatography mass spectrometry. The limits of quantification were 5 ng/mL for MDMA and MDA and 10 ng/mL for HMA and HMMA. Results: MDMA was the primary analyte detected, with concentrations up to 12,000 ng/mL in 872 specimens (67.8%). MDA was quantified in 656 specimens (51.0%) at concentrations <403 ng/mL and was never present without concurrent MDMA. HMA and HMMA were not detected. Of the specimens, 59.8%, 58.6%, and 54.9% were found to be MDMA positive at the Talloires (20 ng/mL), Driving under the Influence of Drugs, Alcohol, and Medicines (25 ng/mL) and proposed US Substance Abuse and Mental Health Services Administration (50 ng/mL) confirmation cutoffs, respectively. MDMA was first observed in oral fluid 0.25-1.25 hours after dosing; MDA was initially detected at 0.5-1.75 hours. In general, the windows of detection for MDMA and MDA were 47 and 29 hours, respectively, although a few specimens were positive up to 71 and 47 hours. Conclusions: Oral fluid monitoring efficiently detects single, recreational 70-150 mg of MDMA use for 1-2 days. These controlled administration data provide a scientific basis for interpreting MDMA oral fluid test results.

Quantification of 11-Nor-9-Carboxy-Δ9-Tetrahydrocannabinol in Human Oral Fluid by Gas Chromatography–Tandem Mass Spectrometry

Abstract: A sensitive and specific method for the quantification of 11-nor-9-carboxy-[INCREMENT]9-tetrahydrocannabinol (THCCOOH) in oral fluid collected with the Quantisal and Oral-Eze devices was developed and fully validated. Extracted analytes were derivatized with hexafluoroisopropanol and trifluoroacetic anhydride and quantified by gas chromatography–tandem mass spectrometry with negative chemical ionization. Standard curves, using linear least-squares regression with 1/x2 weighting were linear from 10 to 1000 ng/L with coefficients of determination >0.998 for both collection devices. Bias was 89.2%–112.6%, total imprecision 4.0%–5.1% coefficient of variation, and extraction efficiency >79.8% across the linear range for Quantisal-collected specimens. Bias was 84.6%–109.3%, total imprecision 3.6%–7.3% coefficient of variation, and extraction efficiency >92.6% for specimens collected with the Oral-Eze device at all 3 quality control concentrations (10, 120, and 750 ng/L). This effective high-throughput method reduces analysis time by 9 minutes per sample compared with our current 2-dimensional gas chromatography–mass spectrometry method and extends the capability of quantifying this important oral fluid analyte to gas chromatography–tandem mass spectrometry. This method was applied to the analysis of oral fluid specimens collected from individuals participating in controlled cannabis studies and will be effective for distinguishing passive environmental contamination from active cannabis smoking.

Identifying methamphetamine exposure in children.

Objective: Methamphetamine (MAMP) use, distribution, and manufacture remain a serious public health and safety problem in the United States, and children environmentally exposed to MAMP face a myriad of developmental, social, and health risks, including severe abuse and neglect necessitating child protection involvement. It is recommended that drug-endangered children receive medical evaluation and care with documentation of overall physical and mental conditions and have urine drug testing. The primary aim of this study was to determine the best biological matrix to detect MAMP, amphetamine (AMP), methylenedioxymethamphetamine (MDMA), methylenedioxyamphetamine (MDA), and 3,4-methylenedioxyethylamphetamine (MDEA) in environmentally exposed children. Methods: Ninety-one children, environmentally exposed to household MAMP intake, were medically evaluated at the Child and Adolescent Abuse Resource and Evaluation Diagnostic and Treatment Center at the University of California, Davis Children’s Hospital. MAMP, AMP, MDMA, MDA, and MDEA were quantified in urine and oral fluid (OF) by gas chromatography mass spectrometry and in hair by liquid chromatography tandem mass spectrometry. Results: Overall drug detection rates in OF, urine, and hair were 6.9%, 22.1%, and 77.8%, respectively. Seventy children (79%) tested positive for 1 or more drugs in 1 or more matrices. MAMP was the primary analyte detected in all 3 biological matrices. All positive OF (n = 5), and 18 of 19 positive urine specimens also had a positive hair test. Conclusions: Hair analysis offered a more sensitive tool for identifying MAMP, AMP, and MDMA environmental exposure in children than urine or OF testing. A negative urine or hair test does not exclude the possibility of drug exposure, but hair testing provided the greatest sensitivity for identifying drug-exposed children.

Quantification of Eight Cannabinoids Including Cannabidiol in Human Urine Via Liquid Chromatography Tandem Mass Spectrometry

Medical and recreational cannabis legalization has highlighted the importance of being able to identify recent cannabis use and impairment. Monitoring minor plant cannabinoids has been proposed to assist in identifying recent cannabis use. Additionally, cannabidiol (CBD) has been proposed for epilepsy, pain, inflammatory disorder, anxiety, and addiction treatment; therefore, monitoring CBD is of increasing clinical importance. However, few methods exist capable of monitoring extensive panels of traditional cannabinoid analytes and minor cannabinoids (including CBD). This chapter details a liquid chromatography tandem mass spectrometry method capable of measuring Δ9-tetrahydrocannabinol (THC), 11-hydroxy-THC, 11-nor-9-carboxy-THC, cannabinol, cannabigerol, tetrahydrocannabivarin (THCV), and its metabolite, 11-nor-9-carboxy-THCV, in urine.