Cannabinoid Metabolites Research Articles

Monitoring of opiates, cannabinoids and their metabolites in wastewater, surface water and finished water in Catalonia, Spain

The occurrence of several opiates and cannabinoids in wastewaters and surface waters has been investigated. Most of the compounds (8 out of 11) were identified in both influent and effluents of fifteen wastewater treatment plants (WWTPs). Codeine, morphine, EDDP and methadone were detected in almost all samples with median values of 69 ng/L; 63 ng/L; 28 ng/L and 18 ng/L, respectively, whereas the main cannabinoid metabolite THC-COOH presented a median value of 57 ng/L in influents. A rough estimate of heroin and cannabis consumption was performed from the analysis of target urinary metabolites in wastewater influents. Data obtained from influents of rural and urban WWTPs gave 0.07% of heroin consumption (0.67% for the largest urban WWTP) and 4% consumption of cannabinoids, respectively for the population aged between 15 and 64 years old. The presence of opiates and cannabinoids in surface waters used for drinking water production showed the presence of the same compounds identified in wastewater effluents at concentrations up to 76 ng/L for codeine; 31 ng/L for EDDP; 12 ng/L for morphine and 9 ng/L for methadone at the intake of the DWTP. A complete removal of all studied drugs present in surface water was achieved during the potabilization process except for methadone and EDDP (91% and 87% removal, respectively).

Study of the structure‐activity relationship for theoretical molecular descriptors using density functional theory and chemometric methods in cannabinoid metabolites

AbstractA set of 30 cannabinoid metabolites has been investigated from a combination of electronic and chemometric methods. Density functional calculations have been carried out to obtain optimized geometries, energies, and selected molecular properties. These molecular descriptors take into account steric effects, electronic properties, and chemical reactivity. The use of statistical methods including principal component analysis (PCA), hierarchical cluster analysis (HCA) and nonhierarchical cluster analysis (K‐means), nearest neighbor (KNN) and artificial neural networks (ANN) has enabled to classify the compounds into psychoactive, moderately psychoactive and psychoinactive groups in good agreement with experimental evidences. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008

Brain Neuroimaging in Cannabis Use: A Review

In this study, the authors systematically reviewed structural and functional neuroimaging studies of cannabis use. Structural abnormalities generally have not been identified with chronic use. Regular users demonstrate reciprocal changes in brain activity globally and in cerebellar and frontal regions. Abstinence results in decreases, and administration results in increases correlating with subjective intoxication. Chronic use and cannabis administration result in attenuated brain activity in task-activated regions or activation of compensatory regions. Findings correlate partially with neuropsychological data, but generalization is limited by the lack of use of diagnostic criteria, appropriately paired neuropsychological testing or means to better quantify cannabis use and abstinence.

Chronic cannabis use is associated with attention-modulated reduction in prepulse inhibition of the startle reflex in healthy humans

Regardless of a wide research interest the nature of a relationship between cannabis use and schizophrenia is controversial. One of the physiological abnormalities in schizophrenia is attention-modulated deficit in prepulse inhibition (PPI), which is a normal reduction in the startle reflex magnitude when a non-startling stimulus (prepulse) precedes the startling stimulus (pulse). This experiment was designed to determine whether or not otherwise healthy people using cannabis would exhibit attention-modulated deficit in PPI. The startle reflex was recorded in carefully screened healthy humans attending to and ignoring auditory pulse and prepulse stimuli separated by short (20-200 ms) and long prepulse intervals (1600 ms). In contrast to 12 non-using controls, cannabis use in 16 healthy humans was associated with significant reduction in%PPI while attending to auditory stimuli, but not while ignoring them. The PPI was correlated with the duration of cannabis use but not with the concentration of cannabinoid metabolites in urine and the recency of cannabis use in the preceding 24 hours. Cannabis use was not associated with changes in prepulse facilitation of startle reflex magnitude (%PPF) at long prepulse intervals, prepulse facilitation of startle reflex latency and startle reflex magnitude in the absence of prepulses. These results suggest that chronic, but not acute, use of cannabis is associated with schizophrenia-like disruption in PPI in healthy controls. Such reduction in PPI is attention-dependent and does not reflect a global deficit in sensorimotor gating in cannabis users.

Misidentification of prostamides as prostaglandins

Prostaglandins and endogenous cannabinoid metabolites share the same lipid backbone with differing polar head groups at exactly the position through which a large molecule is attached to provide antigenicity and thus raise antisera. Hence, we hypothesized that antisera raised against prostaglandins linked to a large molecule such as BSA at the carboxyl functional group would also recognize endogenous cannabinoid metabolites and lead to highly misleading interpretations of data. We found major cross-reactivity of commercial antisera raised to prostaglandins with endocannabinoid metabolites. Furthermore, in a well-characterized cell line (WISH) or primary amnion tissue explants, endocannabinoid treatment led to increased production of endocannabinoid metabolites as opposed to primary prostaglandins. This was apparent only after separation of products by thin-layer chromatography, because they measured as prostaglandins by radioimmunoassay. These findings have major implications for our interpretation of data in situations in which these prostaglandin-like molecules are formed, and they stress the need for chromatographic or spectrometric confirmation of prostaglandin production detected by antibody-based methods.

An Evaluation of Selected Oral Fluid Point-of-Collection Drug-Testing Devices

Point-of-collection oral fluids drug-testing devices are being marketed for a variety of medico-legal purposes where they may complement existing technologies and be used to detect drugs following recent ingestion. To assess the utility of these devices for use in drugged-driving investigations, we performed a laboratory evaluation of four devices and those results were published previously. In the study reported here, two more devices, Oratect(R) (Branan) and Uplink(R) (OraSure), were evaluated for their ability to detect amphetamines, cocaine, opiates, and cannabinoids. An additional device, Drugwipe (Securtec), was evaluated for the detection of cocaine and cannabinoids. Each of the devices was assessed for their ability to meet the manufacturers' claimed cutoff concentrations and to meet cutoffs proposed for federal workplace programs. In general, the Branan and OraSure devices detected amphetamine, methamphetamine, opiates, and cannabinoid metabolite (THC-COOH) well in the concentration ranges approximating those proposed by the Substance Abuse and Mental Health Services Administration (SAMHSA), but all three devices performed poorly in detecting Delta9-tetrahydrocannabinol (THC) at the proposed SAMHSA cutoff. The ability to accurately and reliably detect cocaine was dependent on the individual device, and the Branan and Securetec devices were more effective than OraSure at detecting parent cocaine.

Estimating the prevalence of cannabinoid use urine testing: A preliminary study in Kerman, Iran

Aims This primary study was performed to determine the prevalence rate of cannabinoid consumed in Kerman (Iran). Measurements Urine samples of 700 males, referred to a clinical lab in Kerman city were collected for detection of cannabinoid metabolites. Assessment analysis was a monophasic immunoassay rapid technique. The study was completely blind and only age and residence of samples were revealed. All stages were confirmed and supervised by the ethics committee. Results The prevalence of cannabinoid use was 0.6%. All four positive cases were urban, with ages 31, 36, 40 and 67. More than 90% of referred cases were urban with mean age of 46.8±16 while the mean age of rural cases was 54.3±17 years. Conclusions Considering the age range and possibility of the underlying disease in the study population, the prevalence of cannabinoid use was more than what was expected. Urine analysis as a method for assessing the prevalence rate requires a wide sample size and age distribution matching the age distribution of the study population. In addition, the entrance criteria should not include sick cases.

Urinary excretion profiles of 11-nor-9-carboxy-Δ 9-tetrahydrocannabinol and 11-hydroxy-Δ 9-THC: cannabinoid metabolites to creatinine ratio study IV

The objective of this study was to compare urinary excretion patterns of two cannabinoid metabolites in subjects with a history of chronic marijuana use. The first metabolite analyzed was nor-9-carboxy-Δ 9-tetrahydrocannabinol (Δ 9-THC-COOH), the major urinary cannabinoid metabolite that is pharmacologically inactive. The second metabolite 11-OH-Δ 9-THC is an active cannabinoid metabolite and is not routinely measured. Urine specimens were collected from four subjects on 12–20 occasions ≥96 h apart in an uncontrolled clinical setting. Creatinine was analyzed in each urine specimen by the colorimetric modified Jaffé reaction on a SYVA 30R biochemical analyzer. All urine specimens analyzed for 11-OH-Δ 9-THC had screened positive for cannabinoids with the EMIT II Plus cannabinoids assay (cut-off 50 ng/mL) on a SYVA 30R analyzer and submitted for Δ 9-THC-COOH confirmation by GC–MS (cut-off concentration 15 ng/mL). Eleven-OH-Δ 9-THC was measured by GC–MS with a cut-off concentration of 3 ng/mL. Both GC–MS methods for cannabinoid metabolites used deuterated internal standards for quantitative analysis. The mean (range) of urinary Δ 9-THC-COOH concentration was 1153 ng/mL (78.7–2634) with a cut-off of 15 ng/mL. The mean (range) of Δ 9-THC-COOH/creatinine ratios (ng/mL Δ 9-THC-COOH/mmol/L creatinine) was 84.1 (8.1–122.1). The mean (range) urinary of 11-OH-Δ 9-THC concentration was 387.6 ng/mL (11.9–783) with a cut-off of 3 ng/mL, and the mean (range) of 11-OH-Δ 9-THC/creatinine ratio (ng/mL 11-OH-Δ 9-THC/mmol/L creatinine) was 29.7 (1.2–40.7). Of the 63 urine specimens submitted for Δ 9-THC-COOH confirmation by GC–MS, 59/63 urine specimens (94%) were positive for Δ 9 -THC-COOH and 51/63 (81%) were positive for 11-OH-Δ 9-THC. Overall, the concentrations of 11-OH-Δ 9-THC in urine specimens collected ≥96 h apart were lower than Δ 9-THC-COOH concentrations in 50/51 of the urine specimens in this population. Further urinary cannabinoid excretion studies are needed to assess whether 11-OH-Δ 9-THC analyses have a role when assessing previous marijuana or hashish use in chronic users whose urine specimens remain positive for Δ 9-THC-COOH for an extended period of time after last drug use.

Urinary excretion profiles of 11-nor-9-carboxy-$Delta;9-tetrahydrocannabinol and 11-hydroxy-$Delta;9-THC: cannabinoid metabolites to creatinine ratio study IV

The objective of this study was to compare urinary excretion patterns of two cannabinoid metabolites in subjects with a history of chronic marijuana use. The first metabolite analyzed was nor-9-carboxy-Δ 9 -tetrahydrocannabinol (Δ 9 -THC-COOH), the major urinary cannabinoid metabolite that is pharmacologically inactive. The second metabolite 11-OH-Δ 9 -THC is an active cannabinoid metabolite and is not routinely measured. Urine specimens were collected from four subjects on 12–20 occasions ≥96 h apart in an uncontrolled clinical setting. Creatinine was analyzed in each urine specimen by the colorimetric modified Jaffé reaction on a SYVA 30R biochemical analyzer. All urine specimens analyzed for 11-OH-Δ 9 -THC had screened positive for cannabinoids with the EMIT II Plus cannabinoids assay (cut-off 50 ng/mL) on a SYVA 30R analyzer and submitted for Δ 9 -THC-COOH confirmation by GC–MS (cut-off concentration 15 ng/mL). Eleven-OH-Δ 9 -THC was measured by GC–MS with a cut-off concentration of 3 ng/mL. Both GC–MS methods for cannabinoid metabolites used deuterated internal standards for quantitative analysis. The mean (range) of urinary Δ 9 -THC-COOH concentration was 1153 ng/mL (78.7–2634) with a cut-off of 15 ng/mL. The mean (range) of Δ 9 -THC-COOH/creatinine ratios (ng/mL Δ 9 -THC-COOH/mmol/L creatinine) was 84.1 (8.1–122.1). The mean (range) urinary of 11-OH-Δ 9 -THC concentration was 387.6 ng/mL (11.9–783) with a cut-off of 3 ng/mL, and the mean (range) of 11-OH-Δ 9 -THC/creatinine ratio (ng/mL 11-OH-Δ 9 -THC/mmol/L creatinine) was 29.7 (1.2–40.7). Of the 63 urine specimens submitted for Δ 9 -THC-COOH confirmation by GC–MS, 59/63 urine specimens (94%) were positive for Δ 9 -THC-COOH and 51/63 (81%) were positive for 11-OH-Δ 9 -THC. Overall, the concentrations of 11-OH-Δ 9 -THC in urine specimens collected ≥96 h apart were lower than Δ 9 -THC-COOH concentrations in 50/51 of the urine specimens in this population. Further urinary cannabinoid excretion studies are needed to assess whether 11-OH-Δ 9 -THC analyses have a role when assessing previous marijuana or hashish use in chronic users whose urine specimens remain positive for Δ 9 -THC-COOH for an extended period of time after last drug use.

Urinary excretion profiles of 11-nor-9-carboxy-Δ 9-tetrahydrocannabinol: a Δ 9-THC-COOH to creatinine ratio study #2

Subjects with a history of chronic marijuana use were screened for cannabinoids in urine specimens with the EMIT ® II Plus cannabinoids assay with a cut-off value of 50 ng/ml. All presumptively positive specimens were submitted for confirmatory analysis for the major urinary cannabinoid metabolite (Δ 9-THC-COOH) by GC–MS with a cut-off value of 15 ng/ml. Creatinine was analyzed in each specimen as an index of dilution. Huestis and Cone [J. Anal. Toxicol. 22 (1998) 445] reported that serial monitoring of Δ 9-THC-COOH to creatinine ratios in paired urine specimens collected at least 24 h apart could differentiate new drug use from residual Δ 9-THC-COOH excretion. The best accuracy (85.4%) for predicting new marijuana use was a Δ 9-THC-COOH/creatinine ratio ≥0.5 (dividing the Δ 9-THC-COOH to creatinine ratio of specimen 2 by the specimen 1 ratio). In a previous study in this laboratory [J. Anal. Toxicol. 23 (1999) 531], urine specimens were collected from chronic marijuana users at least 24 h apart and dilute urine specimens (creatinine values <2.2 μmol/l) were excluded from the data analysis. The objective of the present study was to determine whether creatinine corrected urine specimens positive for cannabinoids could differentiate new marijuana use from the excretion of residual Δ 9-THC-COOH in chronic users of marijuana based on the Huestis 0.5 ratio. Urine specimens ( N=946) were collected from 37 individuals with at least 48 h between collections. All urine specimens were included in the data review irrespective of creatinine concentration. The mean urinary Δ 9-THC-COOH concentration was 302.4 ng/ml, mean Δ 9-THC-COOH/creatinine ratio (ng/ml Δ 9-THC-COOH/(mmol/l) creatinine) was 29.3 and the Huestis ratio calculation indicated new drug use in 83% of all sequentially paired urine specimens. The data were sub-divided into three groups (A–C) based on the mean Δ 9-THC-COOH/creatinine values. Interindividual Δ 9-THC-COOH/creatinine mean values ranged from 2.2 to 13.8 in group A (264 specimens, N=15 subjects) where 80.7% of paired specimens indicated new drug use. In group B, mean Δ 9-THC-COOH/creatinine values ranged from 15.3 to 37.8 in 444 specimens ( N=14 subjects) and 83.3% of paired specimens indicated new drug use. In group C, individual mean Δ 9-THC-COOH/creatinine values were >40.1 (41.3–132.5) in 238 urine specimens ( N=8 subjects) and 85.3% of paired urine specimens indicated new marijuana use. Correcting Δ 9-THC-COOH excretion for urinary dilution and comparing Δ 9-THC-COOH/creatinine concentration ratios of sequentially paired specimens (collected at least 48 h apart) provided an objective indicator of new marijuana use in this population.

Monitoring urinary excretion of cannabinoids by fluorescence-polarization immunoassay: a cannabinoid-to-creatinine ratio study.

Drug testing in substance abuse treatment programs is focused on urine analysis of parent drugs and major metabolites. Huestis reported that serial monitoring of the major urinary cannabinoid metabolite (delta9-THC-COOH)-to-creatinine ratios in paired urine specimens (collected at least 24 hours apart) could differentiate new marijuana or hashish use from residual cannabinoid metabolite excretion in urine after previous drug use. Subjects with a history of chronic marijuana use were screened for cannabinoids in urine over several months by an enzyme immunoassay (EMIT) with a cut-off value of 50 ng/mL. Presumptive positive specimens were confirmed by gas chromatography-mass spectrometry (GC-MS) for delta9-THC-COOH with a cut-off value of 15 ng/mL. The objective of this study was to determine whether a semiquantitative cannabinoids immunoassay (corrected for creatinine concentration) could differentiate new marijuana use from residual cannabinoid excretion in chronic users of marijuana or hashish compared with GC-MS. The criterion for new marijuana use was a cannabinoid-to-creatinine ratio > or =0.5 (dividing the immunoassay quantitative result to creatinine ratio of specimen 2 by the specimen 1 ratio, specimen 3 by the specimen 2 ratio, etc.). Urine specimens were analyzed by fluorescence-polarization immunoassay (FPIA) on an Abbott TDxFLx analyzer after analysis by GC-MS. In 90 urine specimens (group A) with delta9-THC-COOH values determined by GC-MS, the mean delta9-THC-COOH concentration was 44.4 ng/mL (range, 16-100), and the mean FPIA total cannabinoids value was 91.7 ng/mL (range, 21-204 ng/mL) with a correlation coefficient of 0.993 (group A). In 111 specimens (group B), the mean delta9-THC-COOH concentration was 361 ng/mL (range, 101-960 ng/mL). The mean FPIA value was 657 ng/mL (range, 211-1,270 ng/mL), and the correlation coefficient of the B series was 0.975. Percent cross-reactivity for delta9-THC-COOH standards prepared in drug-free urine by FPIA was 82% at 25 ng/mL, 45% at 50 ng/mL, and 50% at 100 ng/mL. Overall, there was 89% agreement (132 of 148 specimens) between FPIA and GC-MS. In 16 of 148 specimens, however, the FPIA and GC-MS paired urine data did not agree. The sensitivity of the FPIA assay was 95.3%, and the specificity was 44.4%. The authors conclude that FPIA cannabinoid analysis should be further evaluated as an alternative to GC-MS quantitation to help distinguish new marijuana use from residual marijuana metabolite excretion in clinical drug treatment programs.

Antimalarial (+)-trans-hexahydrodibenzopyran derivatives from Machaerium multiflorum.

Bioassay-guided fractionation of Machaerium multiflorum yielded the hitherto unreported (+)-trans-hexahydrodibenzopyrans machaeriol A (1) and machaeriol B (2), as well as the known guaiane sesquiterpene (-)-kessane. Structure elucidation was based on (1)H and (13)C NMR data, mainly 2D NMR (1)H-(1)H COSY, (1)H-(13)C HMQC, (1)H-(13)C HMBC, and (1)H-(1)H NOESY experiments. This is the first report of the hexahydrodibenzopyrans from a higher plant other than the genus Cannabis. The cannabimimetic activity was thus evaluated by radioligand binding assay for cannabinoid receptor CB1, which indicated, notably, that both 1 and 2 were inactive. In addition, the cross reactivity of 1 and 2 toward antibodies designed for urinary metabolites of cannabinoids was evaluated with the EMIT and On Line cannabinoids assays. Both compounds showed no response at 100 000 ng/mL in both assays. Machaeriol B (2) demonstrated in vitro antimalarial activity (IC(50) = 120 ng/mL) against Plasmodium falciparum W-2 clone.

Temporal indication of marijuana use can be estimated from plasma and urine concentrations of delta9-tetrahydrocannabinol, 11-hydroxy-delta9-tetrahydrocannabinol, and 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid.

Current technology establishes marijuana use based upon detection of the pharmacologically inactive cannabinoid metabolite (11-nor-delta9-carboxy-tetrahydrocannabinol-9-carboxylic acid, THC-COOH) in urine. No accurate prediction of time of use is possible because THC-COOH has a half-life of 6 days. To determine if a temporal relationship between marijuana use and metabolite excretion patterns could be established, eight healthy user-volunteers (18-35 years old) smoked marijuana cigarettes containing 0% (placebo), 1.77%, and 3.58% delta9-tetrahydrocannabinol (THC). Plasma and urine were collected prior to smoking, 5 min after smoking, and hourly thereafter for 8 h for measurement of cannabinoid concentrations by gas chromatography-mass spectrometry. Mathematical models proposed for determination of recent marijuana use were applied to data from this study and verified the temporal use of marijuana. One subject, who later admitted chronic marijuana use (urine baseline THCCOOH, 529.2 ng/mL; plasma, 75.5 ng/mL), excreted 8beta-dihydroxy-THC, peaking 2 h postsmoking (92.3 ng/mL). Urinary THC, the psychoactive component of marijuana, concentrations peaked 2 h after smoking and declined to assay limit of detection (LOD) (1.5 ng/mL) by 6 h. 11-Hydroxy-delta9-tetrahydrocannabinol (11-OH-THC) and THCCOOH were detectable for the entire 8-h testing period but continued to decrease. Urinary concentrations of THC greater than 1.5 ng/mL suggests marijuana use during the previous 8-h time period.

The Maternal Lifestyle Study: drug use by meconium toxicology and maternal self-report.

The objective of this study was to describe drug use by pregnant women participating in the 4-site Maternal Lifestyle Study of in utero cocaine and/or opiate exposure. Meconium specimens of 8527 newborns were analyzed by immunoassay with GC/MS confirmation for metabolites of cocaine, opiates, cannabinoids, amphetamines, and phencyclidine. Maternal self-report of drug use was determined by hospital interview. The prevalence of cocaine/opiate exposure in the 4 sites was 10.7% with the majority (9.5%) exposed to cocaine based on the combination of meconium analysis and maternal self-report. However, exposure status varied by site and was higher in low birth weight infants (18.6% for very low birth weight and 21.1% for low birth weight). Gas chromatography/mass spectrometry (GC/MS) confirmation of presumptive positive cocaine screens was 75.5%. In the cocaine/opiate-exposed group, 38% were cases in which the mother denied use but the meconium was positive. There was 66% agreement between positive meconium results and positive maternal report. Only 2% of mothers reported that they used only cocaine during pregnancy and mothers were 49 times more likely to use another drug if they used cocaine. Accurate identification of prenatal drug exposure is improved with GC/MS confirmation and when the meconium assay is coupled with a maternal hospital interview. However, the use of GC/MS may have different implications for research than for public policy. We caution against the use of quantitative analysis of drugs in meconium to estimate the degree of exposure. Our study also highlights the polydrug nature of what used to be thought of as a cocaine problem.

Synthesis of [2H6]-labelled metabolites of cannabinoids

Four [2H6]-labelled metabolites of cannabinoids were synthesized for use as internal standards for GC/MS analysis. The hexadeutero-ketone 3, prepared from ketal 1, undergoes a Shapiro reaction to give (±)-6,6-[2H6]dimethyl-11-nor-9-carboxy-Δ9-THC (4a) as the major product. The minor product, (±)-6,6-[2H6]dimethyl-11-nor-9-carboxy-Δ8-THC (4b), was obtained after hydrolysis of its acetate methyl ester which was isolated using preparative HPLC. Reduction of 4a gave (±)-6,6-[2H6]dimethyl-11-hydroxy-Δ9-THC (6). (±)-6,6-[2H6]dimethyl-8β,11-dihydroxy-Δ9-THC (10), was also prepared from 3 using a reported procedure for the non-labelling analog. Copyright © 2000 John Wiley & Sons, Ltd.

In vivo adulteration: excess fluid ingestion causes false-negative marijuana and cocaine urine test results.

Drug users can be highly motivated to obtain negative results on urine drug tests and may attempt to subvert the process by in vivo adulteration. The use of herbal products for "flushing" and "detoxification" is frequently advertised as an effective means of passing drug tests. Accordingly, a study was designed to determine the effects of ingestion of two herbal products, Naturally Klean Herbal Tea and Golden Seal root, and a diuretic medication, hydrochlorothiazide. The herbal tea was prepared in 1 gal of water as specified by the manufacturer. All other products were consumed with 1 gal of water. Two control conditions in which the subject consumed only water (1 gal; 12 oz) were included. The 1-gal liquid treatments were divided into 4-qt aliquots, and 1-qt was consumed each hour for 4 h. All treatments were begun approximately 22 h after smoking of a marijuana cigarette (3.58% THC) and 22 h after intranasal administration of cocaine hydrochloride. Following all treatments with excess fluid, creatinine and specific gravity dropped in 1.5-2.0 h to levels indicative of diluted specimens (<20 mg/dL creatinine, <1.003 specific gravity). Marijuana and cocaine metabolite concentrations by immunoassay (EMIT and TDx) also dropped rapidly, and the results frequently switched from positive to negative. By the time subjects had consumed 2 qt of any fluid, they were generally producing false-negative results. For example, ingestion of excess water produced dilute specimens (<20 mg/dL creatinine; <1.003 specific gravity) in an average time plus or minus the standard error of the mean of 1.47 +/- 0.17 h (N = 5) and 1.45 +/- 0.2 h (N = 5) following smoked marijuana and intranasal cocaine, respectively. In comparison, ingestion of Klean Tea produced dilute specimens in 1.36 +/- 0.07 h (N = 4) and 1.39 +/- 0.11 h (N = 4) following marijuana and cocaine administration. Recovery of urine test measures to pre-treatment levels occurred over a period of 8-10 h. Average detection times for marijuana metabolite appeared to be slightly shorter following ingestion of 1 gal of fluids compared with ingestion of 12 oz of water as a result of the time of testing being near the end of the cannabinoid metabolite excretion phase. Consequently, negative cannabinoid results induced by fluid ingestion rarely returned to positive after excess water was eliminated. In contrast, negative cocaine results reverted to positive quickly after the dilution effects disappeared. It was concluded that excess water ingestion can produce false-negative test results, but the claims of herbal products to be an aid in passing a urine test appear to be unfounded.

A Non-Cannabinoid Immunogen Used to Elicit Antibodies with Broad Cross-Reactivity to Cannabinoid Metabolites

A benzpyran derivative was linked to the lysines of bovine thyroglobulin (BTG) where 69% of the available lysines were modified. This derivative was designed to elicit antibodies that were directed towards the conserved epitopes of cannabinoid metabolites that appear in urine. Polyclonal antibodies from sheep and goats and murine monoclonal antibodies were generated using this immunogen. The cross-reactivity of the antibodies was compared with antibodies generated from the more traditional phenolic-linked or 9-linked immunogens. An ELISA assay was developed using delta 9-11-nor-9-carboxy-tetrahydrocannabinol (COOH-THC) to obtain a standard curve. The antibodies generated using the benzpyran immunogen showed an average of two to three times higher cross-reactivity towards 11-OH-delta 9-THC, 8 beta-OH-delta 9-THC, 8 alpha-OH-delta 9-THC, 11-OH-delta 8-THC, and 8 beta,11-di-OH-delta 9-THC than antibodies that were generated by traditional cannabinoid immunogens. The selectivity of the benzpyran-elicited antibodies was also compared with antibodies derived from traditional immunogens using clinical urine samples that were confirmed for cannabinoids by GC/MS. The total cross-reactive cannabinoid values obtained with the benzpyran-elicited antibodies were 49% higher than the values obtained using the traditional immunogen structures. The benzpyran immunogen-induced antibodies exhibited the same low cross-reactivity for non-structurally related compounds as antibodies derived from traditional immunogens. The novel benzpyran immunogen used in this study is the first non-cannabinoid immunogen used to generate cannabinoid-selective antibodies and demonstrates the usefulness of such a structure in developing broadly cross-reactive cannabinoid antibodies.

Passive inhalation of cannabis smoke: a novel defence strategy?

Defence lawyers sometimes argue that the presence of cannabinoid metabolites in the defendant's blood or urine resulted from passive unintentional inhalation of environmental cannabis smoke. It would be useful to be able to differentiate passive inhalation from active use so as to discourage the potential abuse of this phenomenon by the defence. Four cases from two jurisdictions in which passive cannabis smoking was used as a defence are presented to illustrate this dilemma. It remains impossible to define objectively an upper limit for blood and urine levels in cases of passive inhalation of cannabis from the environment. However, a claim of passive inhalation, or indeed ‘deliberate passive exposure’ could be discouraged by making it an offence to place oneself in a position of being ‘concerned’ in the use of the drug. The onus should be on the defendant to prove that he had not attempted to extricate himself from the situation, being aware of the smoking of cannabis in his immediate vicinity; ignorance would not be an excuse.

Use of a visual panel detection method for drugs of abuse: Clinical and laboratory experience with children and adolescents

We evaluated the Triage panel for drugs of abuse, a visual method that simultaneously detects seven distinct drug classes in a single aliquot of urine, by use of 1214 urine specimens obtained from children and adolescent patients whose clinical findings warranted a toxicology evaluation. A total of 295 positive results were confirmed by gas chromatography- mass spectrometry. Additional toxicology investigations were not performed on specimens with negative results unless the clinical findings did not correspond with the urine Triage results. The positive predictive value of the test was found to be > 85% for detection of barbiturates, cannabinoid metabolite, cocaine metabolite, and opiates; for the benzodiazepines the positive predictive value was 77%. Positive predictive values were 53% for amphetamines and 40% for phencyclidine, although only five specimens were available for evaluation of the latter drug. Correlation between clinical findings of patients and results from the Triage test were good except for ingestion of sympathomimetic amines (because of selectivity of the antibodies used in the test for amphetamines) and in patients receiving either antianxiety or antidepressant drugs (some membhers of these classes of drugs or their metabolites appeared to cross-react with the benzodiazepine test). The primary advantages of the Triage test were the rapid turnaround time, the ease with which a specimen could be processed, and the ability to use rapidly provided information as part of a differential diagnosis. (J P EDIATR 1995;126:135-40)

Direct stopped-flow fluorescence polarization immunoassay of abused drugs and their metabolites in urine

Kinetic methodology was applied to the direct determination of abused drugs (amphetamines, cocaine, and cannabinoids) in urine by stopped-flow fluorescence polarization immunoassay (SF-FPIA). This technique provides analytical data within a few seconds by measuring the variation of polarized fluorescence with time during development of immunochemical reactions. Methods based on this principle are particularly suitable for routine screening of these drugs in urine, being more expeditious than conventional FPIA methods. The dynamic ranges of the calibration curves were 20-300 micrograms/L for d,l-amphetamine, 15-300 micrograms/L for benzoylecgonine (a cocaine metabolite), and 10-400 micrograms/L for 11-nor-delta 8-tetrahydrocannabinol-9-carboxylic acid (a cannabinoid metabolite). The detection limits and within- and between-assay precision were better than those provided by conventional FPIA. Analytical recoveries ranged between 97.5% for d,l-amphetamine and 102.4% for the cannabinoid metabolite. The results for the three analytes were consistent with those obtained by conventional FPIA.