2727 B.C.
 First recorded use of cannabis as medicine in Chinese pharmacopoeia. In every part of the world humankind has used cannabis for a wide variety of health problems.

o




A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  Loading
embed this widget
add a cannabis website to index

DRUG TESTING - BLOOD & Cannabis studies completed

also see Drug Testing: Hair, Oral, Other, and Urine

How long do drug tests detect marijuana in blood? There is no simple answer to this question. Detection time depends strongly on the kind and sensitivity of the test employed; the frequency, dosage, and last time of use; the individual subject's genetic make-up, the state of one's metabolism, digestive and excretory systems; and other random, unknown factors.

Blood tests, unlike urinalysis, detect the presence illicit drugs, not inactive drug metabolites. In general, THC only remains detectable in the blood of cannabis consumers for a few hours (though low, residual levels may be detected in chronic smokers for up to 12-24+ hours if more sensitive technology is used). Because of this narrow detection window, blood tests are typically only administered in the workplace post-accident in order to estimate recent cannabis consumption. Therefore, most after-hours consumers have little to fear from a blood screen.

1971 - Study ~ Delta-9-tetrahydrocannabinol: Metabolism and Disposition in Long-term Marihuana Smokers.

1984 - Study ~ Stability of delta 9-tetrahydrocannabinol (THC), 11-hydroxy-THC, and 11-nor-9-carboxy-THC in blood and plasma.

1986 - Study ~ Tetrahydrocannabinol stability in whole blood: plastic versus glass containers.

2003 - Study ~ Serum cannabinoid levels 24 to 48 hours after cannabis smoking

2005 - Study ~ Estimating the Time of Last Cannabis Use from Plasma {Delta}9-Tetrahydrocannabinol and 11-nor-9-Carboxy-{Delta}9-Tetrahydrocannabinol Concentrations

2008 - Study ~ Driving under the influence of cannabis: a 10-year study of age and gender differences in the concentrations of tetrahydrocannabinol in blood.

2008 - Study ~ Cannabinoid concentrations in spot serum samples 24-48 hours after discontinuation of cannabis smoking.

2008 - Study ~ Simultaneous analysis of THC and its metabolites in blood using liquid chromatography-tandem mass spectrometry.

2009 - Study ~ Identification of Recent Cannabis Use:Whole-Blood and Plasma Free and Glucuronidated Cannabinoid Pharmacokinetics Following Controlled Smoked Cannabis Administration.

2009 - Study -  A semi-automated solid-phase extraction liquid chromatography/tandem mass spectrometry method for the analysis of tetrahydrocannabinol and metabolites in whole blood

2009 - Study - Do Delta(9)-tetrahydrocannabinol concentrations indicate recent use in chronic cannabis users?

2010 - Study ~ Concentrations of delta9-tetrahydrocannabinol and 11-nor-9-carboxytetrahydrocannabinol in blood and urine after passive exposure to Cannabis smoke in a coffee shop.

2010 - Study ~ Interpretation of blood analysis data found after passive exposure to cannabis

2010 - Study ~ Testing for cannabis in the work-place: a review of the evidence.

2011 - Study ~ Oral Fluid and Plasma Cannabinoid Ratios after Around-the-Clock Controlled Oral {Delta}9-Tetrahydrocannabinol Administration.

2011 - Study ~ Identification of Recent Cannabis Use:Whole-Blood and Plasma Free and Glucuronidated Cannabinoid Pharmacokinetics Following Controlled Smoked Cannabis Administration.

2011 - Study ~ Oral Fluid and Plasma Cannabinoid Ratios after Around-the-Clock Controlled Oral {Delta}9-Tetrahydrocannabinol Administration.

2011 - Study ~ Influence of ethanol on cannabinoid pharmacokinetic parameters in chronic users.

2011 - Study ~ Variability of cannabinoid findings in blood

2011 - Study ~ Plasma cannabinoid pharmacokinetics following controlled oral delta9-tetrahydrocannabinol and oromucosal cannabis extract administration.

2011 - News ~ Latest blood test detects 12 popular synthetic cannabinoids in "fake pot".

2011 - News ~ Colorado’s 5ng/ml per se DUID bill dies again as new research backs higher thresholds for regular users

2012 - Study ~ Detection and disposition of JWH-018 and JWH-073 in mice after exposure to "Magic Gold" smoke.

2012 - Study ~ Predictive model accuracy in estimating last Δ(9)-tetrahydrocannabinol (THC) intake from plasma and whole blood cannabinoid concentrations in chronic, daily cannabis smokers administered subchronic oral THC.

2012 - Study ~ Detection and quantification of new designer drugs in human blood: part 1 - synthetic cannabinoids.

2012 - Study ~ Analysis of 30 synthetic cannabinoids in serum by liquid chromatography-electrospray ionization tandem mass spectrometry after liquid-liquid extraction

2012 - Study ~ Does a positive finding of tetrahydrocannabinol in the blood result from ingestion of Indian frankincense (Boswellia serrata)?

2012 - Study ~ Psychomotor Performance, Subjective and Physiological Effects and Whole Blood Δ9-
Tetrahydrocannabinol Concentrations in Heavy, Chronic Cannabis Smokers Following
Acute Smoked Cannabis

2012 - Study ~ Detection and disposition of JWH-018 and JWH-073 in mice after exposure to "Magic
Gold" smoke

2012 - Study ~ Determination of naphthalen-1-yl-(1-pentylindol-3-yl)methanone (JWH-018) in mouse
blood and tissue after inhalation exposure to ‘buzz’ smoke by HPLC/MS/MS

2012 - Study ~ Distribution of free and conjugated cannabinoids in human bile samples.

2012 - Study ~ Dried Blood Spots: Liquid chromatography-mass spectrometry analysis of Δ(9)-
tetrahydrocannabinol and its main metabolites.

2013 - Study ~ Simultaneous and sensitive LC–MS/MS determination of tetrahydrocannabinol and
metabolites in human plasma

2013 - Study ~ In Vitro Stability of Free and Glucuronidated Cannabinoids in Blood and Plasma
Following Controlled Smoked Cannabis.

2013 - Study ~ Impact of prolonged cannabinoid excretion in chronic daily cannabis smokers' blood on
per se drugged driving laws.

2013 - Study ~ Oral fluid/plasma cannabinoid ratios following controlled oral THC and smoked cannabis
administration.

2013 - Study ~ Exercise increases plasma THC concentrations in regular cannabis users.

2013 - Study ~ Plasma Cannabinoid Concentrations During Dronabinol Pharmacotherapy for Cannabis
Dependence.

2013 - Study ~ Prevalence of synthetic cannabinoids in blood samples from Norwegian drivers suspected
of impaired driving during a seven weeks period.

2013 - Study ~ THCCOOH concentrations in whole blood: Are they useful in discriminating occasional
from heavy smokers?

2013 - Study ~ Comparison of cannabinoid concentrations in oral fluid and whole blood between
occasional and regular cannabis smokers prior to and after smoking a cannabis joint.

2013 - Study ~ Prevalence of alcohol and other drugs and the concentrations in blood of drivers killed in
road traffic crashes in Sweden.

2013 - Study ~ Quantification of anandamide and 2-arachidonoylglycerol plasma levels to examine
potential influences of tetrahydrocannabinol application on the endocannabinoid system

in humans

2013 - News ~ Michigan driver who uses medical marijuana wins appeal

2013 - News ~ Drug Testing Gets Harder: Exercise Causes THC Levels To Spike


 

 

Top      Home

Do Delta(9)-tetrahydrocannabinol concentrations indicate recent use in chronic cannabis users?

Karschner EL, Schwilke EW, Lowe RH, Darwin WD, Pope HG, Herning R, Cadet JL, Huestis MA

 

Institution

Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, USA.

 

Abstract

 

 AIMS: To quantify blood Delta(9)-tetrahydrocannabinol (THC) concentrations in chronic cannabis users over 7 days of continuous monitored abstinence.


PARTICIPANTS: Twenty-five frequent, long-term cannabis users resided on a secure clinical research unit at the US National Institute on Drug Abuse under continuous medical surveillance to prevent cannabis self-administration.


MEASUREMENTS: Whole blood cannabinoid concentrations were determined by two-dimensional gas chromatography-mass spectrometry.


FINDINGS: Nine chronic users (36%) had no measurable THC during 7 days of cannabis abstinence; 16 had at least one positive THC > or =0.25 ng/ml, but not necessarily on the first day. On day 7, 6 full days after entering the unit, six participants still displayed detectable THC concentrations [mean +/- standard deviation (SD), 0.3 +/- 0.7 ng/ml] and all 25 had measurable carboxy-metabolite (6.2 +/- 8.8 ng/ml). The highest observed THC concentrations on admission (day 1) and day 7 were 7.0 and 3.0 ng/ml, respectively. Interestingly, five participants, all female, had THC-positive whole blood specimens over all 7 days. Body mass index did not correlate with time until the last THC-positive specimen (n = 16; r = -0.2; P = 0.445).


CONCLUSIONS: Substantial whole blood THC concentrations persist multiple days after drug discontinuation in heavy chronic cannabis users. It is currently unknown whether neurocognitive impairment occurs with low blood THC concentrations, and whether return to normal performance, as documented previously following extended cannabis abstinence, is accompanied by the removal of residual THC in brain. These findings also may impact on the implementation of per se limits in driving under the influence of drugs legislation.

 

 

Top      Home

A semi-automated solid-phase extraction liquid chromatography/tandem mass spectrometry method for the analysis of tetrahydrocannabinol and metabolites in whole blood

Jagerdeo E, Schaff JE, Montgomery MA, LeBeau MA

Rapid Commun Mass Spectrom 2009 Sep; 23(17):2697-705.


Marijuana is one of the most commonly abused illicit substances in the USA, making cannabinoids important to detect in clinical and forensic toxicology laboratories. Historically, cannabinoids in biological fluids have been derivatized and analyzed by gas chromatography/mass spectrometry (GC/MS). There has been a gradual shift in many laboratories towards liquid chromatography/mass spectrometry (LC/MS) for this analysis due to its improved sensitivity and reduced sample preparation compared with GC/MS procedures. This paper reports a validated method for the analysis of Delta(9)-tetrahydrocannabinol (THC) and its two main metabolites, 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH) and 11-hydroxy-Delta(9)-tetrahydrocannabinol (THC-OH), in whole blood samples.

 

The method has also been validated for cannabinol (CBD) and cannabidiol (CDN), two cannabinoids that were shown not to interfere with the method. This method has been successfully applied to samples both from living people and from deceased individuals obtained during autopsy. This method utilizes online solid-phase extraction (SPE) with LC/MS. Pretreatment of samples involves protein precipitation, sample concentration, ultracentrifugation, and reconstitution. The online SPE procedure was developed using Hysphere C8-EC sorbent.

 

A chromatographic gradient with an Xterra MS C(18) column was used for the separation. Four multiple-reaction monitoring (MRM) transitions were monitored for each analyte and internal standard. Linearity generally fell between 2 and 200 ng/mL. The limits of detection (LODs) ranged from 0.5 to 3 ng/mL and the limits of quantitation (LOQs) ranged from 2 to 8 ng/mL. The bias and imprecision were determined using a simple analysis of variance (ANOVA: single factor). The results demonstrate bias as <7%, and imprecision as <9%, for all components at each quantity control level.

 

 

 
Top      Home