Urinary Pharmacokinetic Profile of Cannabinoids Following Administration of Vaporized and Oral Cannabidiol and Vaporized CBD-Dominant Cannabis.

Cannabis products in which cannabidiol (CBD) is the primary chemical constituent (CBD-dominant) are increasingly popular and widely available. The impact of CBD exposure on urine drug testing has not been well studied. This study characterized the urinary pharmacokinetic profile of 100-mg oral and vaporized CBD, vaporized CBD-dominant cannabis (100-mg CBD; 3.7-mg ∆9-THC) and placebo in healthy adults (n = 6) using a within-subjects crossover design. Urine specimens were collected before and for 5 days after drug administration. Immunoassay (IA) screening (cutoffs of 20, 50 and 100 ng/mL) and LC-MS-MS confirmatory tests (cutoff of 15 ng/mL) for 11-nor-9-carboxy-∆9-tetrahydrocannabinol (∆9-THCCOOH) were performed; urine was also analyzed for CBD and other cannabinoids. Urinary concentrations of CBD were higher after oral (mean Cmax: 776 ng/mL) versus vaporized CBD (mean Cmax: 261 ng/mL). CBD concentrations peaked 5 h after oral CBD ingestion and within 1 h after inhalation of vaporized CBD. After pure CBD administration, only 1 out of 218 urine specimens screened positive for ∆9-THCCOOH (20-ng/mL IA cutoff) and no specimens exceeded the 15-ng/mL confirmatory cutoff. After inhalation of CBD-dominant cannabis vapor, nine samples screened positive at the 20-ng/mL IA cutoff, and two of those samples screened positive at the 50-ng/mL IA cutoff. Four samples that screened positive (two at 20 ng/mL and two at 50 ng/mL) confirmed positive with concentrations of ∆9-THCCOOH exceeding 15 ng/mL. These data indicate that acute dosing of pure CBD will not result in a positive urine drug test using current federal workplace drug testing guidelines (50-ng/mL IA cutoff with 15-ng/mL confirmatory cutoff). However, CBD products that also contain ∆9-THC may produce positive urine results for ∆9-THCCOOH. Accurate labeling and regulation of ∆9-THC content in CBD/hemp products are needed to prevent unexpected positive drug tests and unintended drug effects.

Acute Pharmacokinetic Profile of Smoked and Vaporized Cannabis in Human Blood and Oral Fluid.

Currently, an unprecedented number of individuals can legally access cannabis. Vaporization is increasingly popular as a method to self-administer cannabis, partly due to perception of reduced harm compared with smoking. Few controlled laboratory studies of cannabis have used vaporization as a delivery method or evaluated the acute effects of cannabis among infrequent cannabis users. This study compared the concentrations of cannabinoids in whole blood and oral fluid after administration of smoked and vaporized cannabis in healthy adults who were infrequent users of cannabis. Seventeen healthy adults, with no past-month cannabis use, self-administered smoked or vaporized cannabis containing Δ9-tetrahydrocannabinol (THC) doses of 0, 10 and 25 mg in six double-blind outpatient sessions. Whole blood and oral fluid specimens were obtained at baseline and for 8 h after cannabis administration. Cannabinoid concentrations were assessed with enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-tandem mass spectrometry (LC-MS-MS) methods. Sensitivity, specificity and agreement between ELISA and LC-MS-MS results were assessed. Subjective, cognitive performance and cardiovascular effects were assessed. The highest concentrations of cannabinoids in both whole blood and oral fluid were typically observed at the first time point (+10 min) after drug administration. In blood, THC, 11-OH-THC, THCCOOH and THCCOOH-glucuronide concentrations were dose-dependent for both methods of administration, but higher following vaporization compared with smoking. THC was detected longer in oral fluid compared to blood and THCCOOH detection in oral fluid was rare and highly erratic. For whole blood, greater detection sensitivity for ELISA testing was observed in vaporized conditions. Conversely, for oral fluid, greater sensitivity was observed in smoked sessions. Blood and/or oral fluid cannabinoid concentrations were weakly to moderately correlated with pharmacodynamic outcomes. Cannabis pharmacokinetics vary by method of inhalation and biological matrix being tested. Vaporization appears to be a more efficient method of delivery compared with smoking.

Acute Effects of Smoked and Vaporized Cannabis in Healthy Adults Who Infrequently Use Cannabis: A Crossover Trial.

Importance: Vaporization is an increasingly popular method for cannabis administration, and policy changes have increased adult access to cannabis drastically. Controlled examinations of cannabis vaporization among adults with infrequent current cannabis use patterns (>30 days since last use) are needed. Objective: To evaluate the acute dose effects of smoked and vaporized cannabis using controlled administration methods. Design, Setting, and Participants: This within-participant, double-blind, crossover study was conducted from June 2016 to January 2017 at the Behavioral Pharmacology Research Unit, Johns Hopkins University School of Medicine, and included 17 healthy adults. Six smoked and vaporized outpatient experimental sessions (1-week washout between sessions) were completed in clusters (order counterbalanced across participants); dose order was randomized within each cluster. Interventions: Cannabis containing Δ9-tetrahydrocannabinol (THC) doses of 0 mg, 10 mg, and 25 mg was vaporized and smoked by each participant. Main Outcomes and Measures: Change from baseline scores for subjective drug effects, cognitive and psychomotor performance, vital signs, and blood THC concentration. Results: The sample included 17 healthy adults (mean [SD] age, 27.3 [5.7] years; 9 men and 8 women) with no cannabis use in the prior month (mean [SD] days since last cannabis use, 398 [437] days). Inhalation of cannabis containing 10 mg of THC produced discriminative drug effects (mean [SD] ratings on a 100-point visual analog scale, smoked: 46 [26]; vaporized: 69 [26]) and modest impairment of cognitive functioning. The 25-mg dose produced significant drug effects (mean [SD] ratings, smoked: 66 [29]; vaporized: 78 [24]), increased incidence of adverse effects, and pronounced impairment of cognitive and psychomotor ability (eg, significant decreased task performance compared with placebo in vaporized conditions). Vaporized cannabis resulted in qualitatively stronger drug effects for most pharmacodynamic outcomes and higher peak concentrations of THC in blood, compared with equal doses of smoked cannabis (25-mg dose: smoked, 10.2 ng/mL; vaporized, 14.4 ng/mL). Blood THC concentrations and heart rate peaked within 30 minutes after cannabis administration and returned to baseline within 3 to 4 hours. Several subjective drug effects and observed cognitive and psychomotor impairments persisted for up to 6 hours on average. Conclusions and Relevance: Vaporized and smoked cannabis produced dose-orderly drug effects, which were stronger when vaporized. These data can inform regulatory and clinical decisions surrounding the use of cannabis among adults with little or no prior cannabis exposure. Trial Registration: ClinicalTrials.gov Identifier: NCT03676166.

Nonsmoker Exposure to Secondhand Cannabis Smoke. III. Oral Fluid and Blood Drug Concentrations and Corresponding Subjective Effects.

The increasing use of highly potent strains of cannabis prompted this new evaluation of human toxicology and subjective effects following passive exposure to cannabis smoke. The study was designed to produce extreme cannabis smoke exposure conditions tolerable to drug-free nonsmokers. Six experienced cannabis users smoked cannabis cigarettes [5.3% Δ(9)-tetrahydrocannabinol (THC) in Session 1 and 11.3% THC in Sessions 2 and 3] in a closed chamber. Six nonsmokers were seated alternately with smokers during exposure sessions of 1 h duration. Sessions 1 and 2 were conducted with no ventilation and ventilation was employed in Session 3. Oral fluid, whole blood and subjective effect measures were obtained before and at multiple time points after each session. Oral fluid was analyzed by ELISA (4 ng/mL cutoff concentration) and by LC-MS-MS (limit of quantitation) for THC (1 ng/mL) and total THCCOOH (0.02 ng/mL). Blood was analyzed by LC-MS-MS (0.5 ng/mL) for THC, 11-OH-THC and free THCCOOH. Positive tests for THC in oral fluid and blood were obtained for nonsmokers up to 3 h following exposure. Ratings of subjective effects correlated with the degree of exposure. Subjective effect measures and amounts of THC absorbed by nonsmokers (relative to smokers) indicated that extreme secondhand cannabis smoke exposure mimicked, though to a lesser extent, active cannabis smoking.

Non-smoker exposure to secondhand cannabis smoke II: Effect of room ventilation on the physiological, subjective, and behavioral/cognitive effects.

INTRODUCTION: Cannabis is the most widely used illicit drug. Many individuals are incidentally exposed to secondhand cannabis smoke, but little is known about the effects of this exposure. This report examines the physiological, subjective, and behavioral/cognitive effects of secondhand cannabis exposure, and the influence of room ventilation on these effects. METHODS: Non-cannabis-using individuals were exposed to secondhand cannabis smoke from six individuals smoking cannabis (11.3% THC) ad libitum in a specially constructed chamber for 1h. Chamber ventilation was experimentally manipulated so that participants were exposed under unventilated conditions or with ventilation at a rate of 11 air exchanges/h. Physiological, subjective and behavioral/cognitive measures of cannabis exposure assessed after exposure sessions were compared to baseline measures. RESULTS: Exposure to secondhand cannabis smoke under unventilated conditions produced detectable cannabinoid levels in blood and urine, minor increases in heart rate, mild to moderate self-reported sedative drug effects, and impaired performance on the digit symbol substitution task (DSST). One urine specimen tested positive at using a 50 ng/ml cut-off and several specimens were positive at 20 ng/ml. Exposure under ventilated conditions resulted in much lower blood cannabinoid levels, and did not produce sedative drug effects, impairments in performance, or positive urine screen results. CONCLUSIONS: Room ventilation has a pronounced effect on exposure to secondhand cannabis smoke. Under extreme, unventilated conditions, secondhand cannabis smoke exposure can produce detectable levels of THC in blood and urine, minor physiological and subjective drug effects, and minor impairment on a task requiring psychomotor ability and working memory.

Non-smoker exposure to secondhand cannabis smoke. I. Urine screening and confirmation results.

Increased cannabis potency has renewed concerns that secondhand exposure to cannabis smoke can produce positive drug tests. A systematic study was conducted of smoke exposure on drug-free participants. Six experienced cannabis users smoked cannabis cigarettes (5.3% THC in Session 1 and 11.3% THC in Sessions 2 and 3) in a sealed chamber. Six non-smokers were seated with smokers in an alternating manner. Sessions 1 and 2 were conducted with no ventilation and ventilation was employed in Session 3. Non-smoking participant specimens (collected 0-34 h) were analyzed with four immunoassays at different cutoff concentrations (20, 50, 75 and 100 ng/mL) and by GC-MS (LOQ = 0.75 ng/mL). No presumptive positives occurred for non-smokers at 100 and 75 ng/mL; a single positive occurred at 50 ng/mL; and multiple positives occurred at 20 ng/mL. Maximum THCCOOH concentrations by GC-MS for non-smokers ranged from 1.3 to 57.5 ng/mL. THCCOOH concentrations generally increased with THC potency, but room ventilation substantially reduced exposure levels. These results demonstrate that extreme cannabis smoke exposure can produce positive urine tests at commonly utilized cutoff concentrations. However, positive tests are likely to be rare, limited to the hours immediately post-exposure, and occur only under environmental circumstances where exposure is obvious.

Prevalence of heroin markers in urine for pain management patients.

Surveys of current trends indicate heroin abuse is associated with nonmedical use of pain relievers. Consequently, there is an interest in evaluating the presence of heroin-specific markers in chronic pain patients who are prescribed controlled substances. A total of 926,084 urine specimens from chronic pain patients were tested for heroin/diacetylmorphine (DAM), 6-acetylmorphine (6AM), 6-acetylcodeine (6AC), codeine (COD), and morphine (MOR). Heroin and markers were analyzed using liquid chromatography tandem mass spectrometry (LC-MS-MS). Opiates were analyzed following hydrolysis using LC-MS-MS. The prevalence of heroin use was 0.31%, as 2871 were positive for one or more heroin-specific markers including DAM, 6AM, or 6AC (a known contaminant of illicit heroin). Of these, 1884 were additionally tested for the following markers of illicit drug use: 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyamphetamine (MDA), methamphetamine (MAMP), 11-nor-9-carboxy-Δ(9)-tetracannabinol (THCCOOH), and benzoylecgonine (BZE); 654 (34.7%) had positive findings for one or more of these analytes. The overall prevalence of heroin markers were as follows: DAM 1203 (41.9%), 6AM 2570 (89.5%), 6AC 1082 (37.7%). MOR was present in 2194 (76.4%) and absent (

Oral fluid results compared to self reports of recent cocaine and heroin use by methadone maintenance patients.

INTRODUCTION: Although self reports of illicit drug use may not be reliable, this information is frequently collected and relied upon by national drug surveys and by counselors in drug treatment programs. The addition of oral fluid testing to these programs would provide objective information on recent drug use. AIM: The goal of this study was to compare oral fluid tests for cocaine, benzoylecgonine, 6-acetylmorphine, morphine, codeine and 6-acetylcodeine to self reports of recent cocaine and heroin use by patients in an outpatient methadone treatment program. METHODS: Patients (n=400) provided an oral fluid specimen and completed a short questionnaire on illicit drug use over the last seven days. Oral fluid was collected with the Intercept Oral Fluid Collection device. Oral fluid was analyzed by a validated assay using liquid chromatography coupled with tandem mass spectrometry. The presence of an analyte was confirmed if all identification criteria were met and its concentration (ng/mL) was ≥ LOQ (cocaine, 0.4; benzoylecgonine, 0.4; morphine, 2; codeine, 2; 6-acetylmorphine, 0.4; and 6-acetylcodeine, 1). RESULTS: Analyses of oral fluid specimens collected from the 400 methadone maintained patients revealed that a majority (95%) of subjects who admitted to recent cocaine use were confirmed positive, whereas slightly more than 50% were confirmed positive who admitted to heroin over the last seven days. For those patients who denied recent cocaine and heroin use, approximately 30% were positive for cocaine and 14% were positive for heroin. CONCLUSION: Oral fluid testing provides an objective means of verifying recent drug use and for assessment of patients in treatment for substance use disorders.

Normalization of urinary drug concentrations with specific gravity and creatinine.

Excessive fluid intake can substantially dilute urinary drug concentrations and result in false-negative reports for drug users. Methods for correction ("normalization") of drug/metabolite concentrations in urine have been utilized by anti-doping laboratories, pain monitoring programs, and in environmental monitoring programs to compensate for excessive hydration, but such procedures have not been used routinely in workplace, legal, and treatment settings. We evaluated two drug normalization procedures based on specific gravity and creatinine. These corrections were applied to urine specimens collected from three distinct groups (pain patients, heroin users, and marijuana/ cocaine users). Each group was unique in characteristics, study design, and dosing conditions. The results of the two normalization procedures were highly correlated (r=0.94; range, 0.78-0.99). Increases in percent positives by specific gravity and creatinine normalization were small (0.3% and -1.0%, respectively) for heroin users (normally hydrated subjects), modest (4.2-9.8%) for pain patients (unknown hydration state), and substantial (2- to 38-fold increases) for marijuana/cocaine users (excessively hydrated subjects). Despite some limitations, these normalization procedures provide alternative means of dealing with highly dilute, dilute, and concentrated urine specimens. Drug/metabolite concentration normalization by these procedures is recommended for urine testing programs, especially as a means of coping with dilute specimens.

Rapid absorption of nicotine from new nicotine gum formulations.

RATIONALE: A clinically limiting feature of currently-available nicotine gum is its slow rate of nicotine delivery and consequently slow onset of therapeutic effects. Previous research suggested that a nicotine hydrogen tartrate gum (NHTG1) that delivered nicotine more rapidly provided more effective craving relief. A subsequent gum formulation (NTHG2) was developed to further increase speed of delivery. OBJECTIVE: Compare the plasma nicotine absorption and clinical tolerability of NHTG2 to NHTG1 and Nicorette FreshMint. METHODS: A single-dose, randomized, crossover study evaluated the early kinetics of nicotine absorption and tolerability of 4 mg NHTG2 compared to NHTG1 and Nicorette. RESULTS: NHTG2 gum reached higher Cmax (p=0.059 versus Nicorette; p=0.006 versus NHTG1) and delivered significantly more nicotine than Nicorette or NHTG1 within the first 10-30 min of chewing (AUCs0-10, 0-30) and overall (AUC0-180). NHT gums and Nicorette were well tolerated, with little difference in their AE profiles. CONCLUSIONS: Study results indicate that NHTG2 gum provided more rapid uptake of nicotine in blood without notable decreases in tolerability. To the extent that rate of delivery and onset of therapeutic effects are related, these gums would be expected to provide more rapid therapeutic effects.

Cocaine and metabolites urinary excretion after controlled smoked administration.

Understanding cocaine and metabolites urinary excretion following smoking is important for interpretation of urine test results in judicial, workplace and treatment settings. In National Institute on Drug Abuse approved studies on a secure research unit, six subjects smoked placebo, 10, 20, and 40 mg cocaine with a precise dose delivery device and six different subjects smoked 42 mg cocaine in a glass pipe. Urine specimens (n = 700) were collected for up to seven days and analyzed for cocaine (COC), benzoylecgonine (BE), ecgonine methylester (EME), m-hydroxybenzoylecgonine (mOHBE), p-hydroxybenzoylecgonine (pOHBE), norbenzoylecgonine (NBE), and ecgonine (EC) by gas chromatography-mass spectrometry. Results (mean +/- SE) for the 40-mg precise delivery doses are as follows: (Table can not be represented) Mean C(max) for all analytes linearly increased with increasing dose. T(max) was not dose-dependent. All metabolites were detected in some subjects within 2 h. EC concentrations were significantly higher after smoked cocaine in a precise delivery coil compared to a glass "crack" pipe.

Simultaneous quantification of methamphetamine, cocaine, codeine, and metabolites in skin by positive chemical ionization gas chromatography-mass spectrometry.

A positive chemical ionization gas chromatography-mass spectrometric method was validated to simultaneously quantify drugs and metabolites in skin collected after controlled administration of methamphetamine, cocaine, and codeine. Calibration curves (2.5-100 ng/skin biopsy) for methamphetamine, amphetamine, cocaine, norcocaine, benzoylecgonine, cocaethylene, norcocaethylene, anhydroecgonine methyl ester, morphine, codeine, and 6-acetylmorphine (5-100 ng/skin biopsy for ecgonine methyl ester and ecgonine ethyl ester) exhibited correlation coefficients >0.999 and concentrations +/-20% of target. Intra- and inter-run precisions were <10%. This procedure should be useful for postmortem analysis; data are included on drug concentrations in skin after controlled drug administration.

Relationship between plasma and oral fluid nicotine concentrations in humans: a pilot study.

The relationship between plasma and oral fluid concentrations of nicotine after infusion at varying times was investigated. Five healthy human volunteers were administered 0, 0.75, and 1.5 mg nicotine as 0.5-, 1.0-, 2.5-, and 5-minute infusions. Blood and oral fluid were collected before drug administration and for 4 hours thereafter. Nicotine concentrations were determined by HPLC using a limit of quantification of 1 ng/mL. Plasma nicotine concentrations were dose related. Peak plasma concentrations (mean+/-SD) at the 4 infusion times were 14.1+/-5.5, 11.8+/-5.3, 12.8+/-1.9, and 11.5+/-4.0 ng/mL (N=5) after the 0.75-mg dose and 26.3+/-11.7, 19.3+/-12.8, 24.54+/-10.4, and 19.02+/-6.5 ng/mL after the 1.5-mg dose. In general, the highest peak concentration occurred at the shortest infusion time at each dose. Peak nicotine oral fluid concentrations (mean+/-SD) at the 4 infusion times of 22.4+/-29.1, 22.64+/-29.9, 19.1+/-13.5, and 49.1+/-31.7 ng/mL (n=5) after the low dose and 35.8+/-21.1, 26.0+/-7.7, 33.3+/-28.8, and 104.0+/-68.9 ng/mL, after the 1.5 mg dose. The highest oral fluid concentration of nicotine occurred at the longest infusion time at each dose. Oral fluid/plasma were >1 for up to 60 minutes after the low dose and 120 minutes after the high dose. There was no correlation between plasma and oral fluid nicotine concentrations.

Passive cannabis smoke exposure and oral fluid testing. II. Two studies of extreme cannabis smoke exposure in a motor vehicle.

Two studies were conducted to determine if extreme passive exposure to cannabis smoke in a motor vehicle would produce positive results for delta-tetrahydrocannabinol (THC) in oral fluid. Passive exposure to cannabis smoke in an unventilated room has been shown to produce a transient appearance of THC in oral fluid for up to 30 min. However, it is well known that such factors as room size and extent of smoke exposure can affect results. Questions have also been raised concerning the effects of tobacco when mixed with marijuana and THC content. We conducted two passive cannabis studies under severe passive smoke exposure conditions in an unventilated eight-passenger van. Four passive subjects sat alongside four active cannabis smokers who each smoked a single cannabis cigarette containing either 5.4%, 39.5 mg THC (Study 1) or 10.4%, 83.2 mg THC (Study 2). The cigarettes in Study 1 contained tobacco mixed with cannabis; cigarettes in Study 2 contained only cannabis. Oral fluid specimens were collected from passive and active subjects with the Intercept Oral Specimen Collection Device for 1 h after smoking cessation while inside the van (Study 1) and up to 72 h (passive) or 8 h (active) outside the van. Additionally in Study 1, Intercept collectors were exposed to smoke in the van to assess environmental contamination during collection procedures. For Study 2, all oral fluid collections were outside the van following smoking cessation to minimize environmental contamination. Oral samples were analyzed with the Cannabinoids Intercept MICRO-PLATE EIA and quantitatively by gas chromatography-tandem mass spectrometry (GC-MS-MS). THC concentrations were adjusted for dilution (x 3). The screening and confirmation cutoff concentrations for THC in neat oral fluid were 3 ng/mL and 1.5 ng/mL, respectively. The limits of detection (LOD) and quantitation (LOQ) for THC in the GC-MS-MS assay were 0.3 and 0.75 ng/mL, respectively. Urine specimens were collected, screened (EMIT, 50 ng/mL cutoff), and analyzed by GC-MS-MS for THCCOOH (LOD/LOQ = 1.0 ng/mL). Peak oral fluid THC concentrations in passive subjects recorded at the end of cannabis smoke exposure were up to 7.5 ng/mL (Study 1) and 1.2 ng/mL (Study 2). Thereafter, THC concentrations quickly declined to negative levels within 30-45 min in Study 1. It was found that environmentally exposed Collectors contained 3-14 ng/mL in Study 1. When potential contamination during collection was eliminated in Study 2, all passive subjects were negative at screening/confirmation cutoff concentrations throughout the study. Oral fluid specimens from active smokers had peak concentrations of THC approximately 100-fold greater than passive subjects in both studies. Positive oral fluid results were observed for active smokers 0-8 h. Urine analysis confirmed oral fluid results. These studies clarify earlier findings on the effects of passive cannabis smoke on oral fluid results. Oral fluid specimens collected in the presence of cannabis smoke appear to have been contaminated, thereby falsely elevating THC concentrations in oral fluid. The risk of a positive test for THC was virtually eliminated when specimens were collected in the absence of THC smoke.

Relationship of Delta 9-tetrahydrocannabinol concentrations in oral fluid and plasma after controlled administration of smoked cannabis.

Understanding the relationship of Delta(9)-tetrahydrocannabinol (THC) concentrations in oral fluid and plasma is important in interpretation of oral fluid test results. Current evidence suggests that THC is deposited in the oral cavity during cannabis smoking. This "depot" represents the primary or sole source of THC found when oral fluid is collected and analyzed. In this research, oral fluid and plasma specimens were collected from six subjects following smoking of cannabis cigarettes containing 1.75% and 3.55% THC. There was at least one week between each cannabis administration. Plasma specimens were analyzed by gas chromatography-mass spectrometry (GC-MS) and paired oral fluid specimens were analyzed by radioimmunoassay (RIA). In addition, one individual's oral fluid specimens were also analyzed by GC-MS. These data are unique in that they represent simultaneous or near simultaneous collection of oral fluid and plasma specimens in subjects following controlled cannabis dosing. The first oral fluid specimen, collected from one subject at 0.2 h following initiation of smoking, contained a THC concentration of 5800 ng/mL (GC-MS). By 0.33 h, the THC concentration in oral fluid had fallen to 81 ng/mL. From approximately 0.3 h through 4.0 h, the mean (+/- SD) THC ratio of oral fluid to plasma THC concentrations was 1.18 (0.62) with a range of 0.5 to 2.2. Within 12 h, both oral fluid and plasma THC concentrations generally declined below 1 ng/mL. RIA analyses of oral fluid specimens for six subjects demonstrated the same pattern of initial high levels of contamination immediately after smoking, followed by rapid clearing, and a slower decline over 12 h. Mean THC oral fluid concentrations by RIA at 0.2 h were 864 ng/mL and 4167 ng/mL compared to plasma concentrations of 52 ng/mL and 230 ng/mL at 0.27 h following the low- and high-dose cannabis cigarettes, respectively. The similarity in oral fluid and plasma THC concentrations following the dissipation of the initial "contamination" indicates the likelihood of a physiological link between these specimens. Recent studies have shown that sublingual or transmucosal administration of pure THC results in direct absorption of intact THC into the bloodstream, thereby bypassing the gastrointestinal tract. The current study demonstrates that THC is deposited in the oral cavity and remains for up to 24 h following cannabis smoking. The decline in THC oral fluid concentration over this time suggests that there may be absorption of THC into blood as previously shown with pure THC. Passive cannabis exposure studies appear to indicate that positive oral fluid tests for THC can occur shortly after cannabis smoke exposure, but results were negative within 1 h. Consequently, when very recent passive exposure to cannabis smoke can be ruled out, it is concluded that a positive oral fluid test provides credible evidence of active cannabis use.

Passive cannabis smoke exposure and oral fluid testing.

Oral fluid testing for Delta(9)-tetrahydrocannabinol (THC) provides a convenient means of detection of recent cannabis usage. In this study, the risk of positive oral fluid tests from passive cannabis smoke exposure was investigated by housing four cannabis-free volunteers in a small, unventilated, and sealed room with an approximate volume of 36 m(3). Five active cannabis smokers were also present in the room, and each smoked a single cannabis cigarette (1.75% THC). Cannabis smoking occurred over the first 20 min of the study session. All subjects remained in the room for approximately 4 h. Oral fluid specimens were collected with the Intercept DOA Oral Specimen Collection Device. Three urine specimens were collected (0, 20, and 245 min). In addition, three air samples were collected for measurement of THC content. All oral fluid specimens were screened by enzyme immunoassay (EIA) for cannabinoids (cutoff concentration = 3 ng/mL) and tested by gas chromatography-tandem mass spectrometry (GC-MS-MS) for THC (LOQ/LOD = 0.75 ng/mL). All urine specimens were screened by EIA for cannabinoids (cutoff concentration = 50 ng/mL) and tested by GC-MS-MS for THCCOOH (LOQ/LOD = 1 ng/mL). Air samples were measured for THC by GC-MS (LOD = 1 ng/L). A total of eight oral fluid specimens (collected 20 to 50 min following initiation of smoking) from the four passive subjects screened and confirmed positive for THC at concentrations ranging from 3.6 to 26.4 ng/mL. Two additional specimens from one passive subject, collected at 50 and 65 min, screened negative but contained THC in concentrations of 4.2 and 1.1 ng/mL, respectively. All subsequent specimens for passive participants tested negative by EIA and GC-MS-MS for the remainder of the 4-h session. In contrast, oral fluid specimens collected from the five cannabis smokers generally screened and confirmed positive for THC throughout the session at concentrations substantially higher than observed for passive subjects. Urine specimens from active cannabis smokers also screened and confirmed positive at conventional cutoff concentrations. A biphasic pattern of decline for THC was observed in oral fluid specimens collected from cannabis smokers, whereas a linear decline was seen for passive subjects suggesting that initial oral fluid contamination is cleared rapidly and is followed by THC sequestration in the oral mucosa. It is concluded that the risk of positive oral fluid tests from passive cannabis smoke inhalation is limited to a period of approximately 30 min following exposure.

Effects of high-dose intravenous buprenorphine in experienced opioid abusers.

Sublingual buprenorphine, a long-acting, partial mu-opioid agonist, is as effective as methadone in the treatment of heroin dependence, with a better safety profile due to its antagonist activity. However, the safety of therapeutic doses (8 to 16 mg) that might be diverted for intravenous (i.v.) use has not been demonstrated. To evaluate the safety and possible ceiling effects of buprenorphine administered i.v. to experienced opioid users, buprenorphine was administered to 6 nondependent opioid abusers residing on a research unit; the doses tested, in separate sessions, were 12 mg buprenorphine sublingual, i.v./sublingual placebo, and escalating i.v. buprenorphine (2, 4, 8, 12, and 16 mg). Physiologic and subjective measures were collected for 72 hours post-drug administration. Buprenorphine minimally but significantly increased systolic blood pressure. Changes in heart rate or oxygen saturation among the 7 drug conditions were not statistically significant. The mean maximum decrease in oxygen saturation from baseline was greatest for the 8-mg i.v. dose. Buprenorphine produced positive mood effects, although with substantial variability among participants. Onset and peak effects occurred earlier following i.v. administration: peak i.v. effects occurred between 0.25 and 3 hours; peak sublingual effects occurred at 3 to 7 hours. Duration of effects varied among the outcome measures. The dose-response curves were flat for most parameters, particularly subjective measures. Side effects were mild except in one participant who experienced severe nausea and vomiting after the 12-mg i.v. dose. Buprenorphine appears to have a ceiling for cardiorespiratory and subjective effects and a high safety margin even when taken by the i.v. route.

Urine testing for cocaine abuse: metabolic and excretion patterns following different routes of administration and methods for detection of false-negative results.

Although cocaine is typically the second-most identified drug of abuse in drug-testing programs, there is surprisingly little quantitative information on excretion patterns following different routes of administration. This report details the urinary excretion and terminal elimination kinetics for cocaine and eight metabolites [benzoylecgonine (BZE), ecgonine methylester (EME), norcocaine (NCOC), benzoylnorecgonine (BNE), m-hydroxy-BZE (m-HO-BZE), p-hydroxy-BZE (p-HO-BZE), m-hydroxy-COC (m-HO-COC), and p-hydroxy-COC (p-HO-COC)]. Six healthy males were administered approximately equipotent doses of cocaine by the intravenous (IV), smoking (SM), and inhalation (IN) routes of administration. Urine specimens were collected for a minimum of three days after drug administration, screened by immunoassay (EMIT and TDX, 300 ng/mL), and analyzed by GC-MS. Mean Cmax values were generally as follows: BZE > EME > COC > BNE approximately p-HO-BZE > m-HO-BZE > m-HO-COC > NCOC > p-HO-COC. Elimination half-lives for cocaine and metabolites were generally shorter following s.m., intermediate after i.v., and longest following i.n. administration. m-HO-BZE demonstrated the longest half-life (mean range 7.0-8.9 h), and cocaine displayed the shortest (2.4-4.0 h). Mean detection times were extended progressively by lowering cutoff concentrations. The maximum increases were approximately 55% at 50 ng/mL for the TDx assay (e.g., the detection time for the last consecutive positive changed from 32.8 h to 50.6 h for i.v. cocaine) and up to 39% for GC-MS at a cutoff concentration of 40 ng/mL (e.g., the detection time for the last consecutive positive changed from 34.8 h to 48.1 h for i.v. cocaine). Sensitivity, specificity, and predictive values for EMIT and TDx were comparable at the 300-ng/mL cutoff concentration; but at lower cutoff concentrations, predictive values of positive results for TDx were diminished indicating a higher risk of false-positive results, that is, positive results that failed to meet administrative cutoff criteria. Detection of positive results was significantly enhanced through the use of the "Zero Threshold Criteria Method", a method developed by the authors to differentiate false-negatives from true-negatives. The method was based on establishing mean immunoassay response (MIR) baselines and variance (SD) in assays of drug-free specimens. Arbitrary thresholds (MIR + 0.5 SD, MIR + 1 SD, MIR + 2 SD) were utilized to evaluate all negative specimens. Apparent true positives were identified by the presence of BZE at or above 40% GC-MS cutoff concentrations. With these criteria, up to 111 false-negative specimens were confirmed as true-positive specimens; this was in addition to the 208 true positives detected at recommended cutoff concentrations. This represents a 50% increase in positive detection rates through the use of this methodology. Such methodology is recommended for further evaluation by drug-testing programs for enhancement of positive detection rates and as an alternative to creatinine testing for dealing with dilute specimens that test negative by initial tests, but contain quantifiable concentrations of drugs of abuse.

Oxycodone involvement in drug abuse deaths: a DAWN-based classification scheme applied to an oxycodone postmortem database containing over 1000 cases.

An oxycodone postmortem database was created from 1243 solicited cases from Medical Examiner and Coroner (ME/C) offices in 23 states in the United States over the period from August 27, 1999, through January 17, 2002. The request for cases was specific to only those cases in which the ME/C opined that the death involved oxycodone. Each case was evaluated to determine the role of oxycodone and the specific drug product OxyContin tablets in the death. Oxycodone identification was based on toxicology testing, and OxyContin identification was based on evidence found at the scene, credible witness reports, or identification of tablets in gastrointestinal contents. A system of case categorization was developed for this study based on the Drug Abuse Warning Network (DAWN) system for reporting drug abuse mortality data in the United States, using the same standardized, well-understood terminology. Of the 1243 cases, 79 cases were incomplete and could not be evaluated. There were an additional 150 cases submitted in which oxycodone was not identified by the originating ME/C. Of the remaining 1014 cases, 919 (90.6%) were related to drug abuse, whereas 95 (9.4%) cases were categorized as not involving drug abuse. Only 30 (3.3%) of the drug abuse cases involved oxycodone as the single reported chemical entity; of these, 12 cases had OxyContin identified as a source of oxycodone. Of the 919 drug abuse cases, the vast majority (N = 889, 96.7%) were multiple drug abuse deaths in which there was at least one other plausible contributory drug in addition to oxycodone. The most prevalent drug combinations were oxycodone in combination with benzodiazepines, alcohol, cocaine, other narcotics, marijuana, or antidepressants. Using the DAWN definitions, drug abuse cases were further categorized as drug-induced or drug-related. A total of 851 (92.6%) cases met the criteria for classification as being drug-induced, and the remaining 68 (7.4%) cases were categorized as drug-related. Cause of death (COD) statements from the originating ME/C indicated a general recognition of the role of abuse of multiple drugs in causing fatalities. Approximately 70% of the 889 cases in the multiple-drug-induced categories were listed in the COD or contributing COD statements as multiple-drug deaths. A variety of terms were employed in the COD statements to indicate multiple drug involvement such as "polydrug toxicity", "polypharmacy", "multiple drug poisoning", and "polypharmaceutical overdose". The system for death classification employed in this study recognizes the problems inherent in COD attribution when multiple drugs are involved. Use of this new system for reporting mortality data in future studies involving opioids is recommended.