For the life of me I can't think what they were doing. Training in how to spot a suspicious car?
Topicals, Edibles and roadside drug tests
Posted 10 May 2017 - 11:08 PM
Ok, so an update. I got my hands on a copy of the last study I mentioned that was in the news in Feb this year. The full title is Cannabis Edibles: Blood and Oral Fluid Cannabinoid Pharmacokinetics and Evaluation of Oral Fluid Screening Devices for Predicting Delta 9 Tetrahydrocannabinol in Blood and Oral Fluid following Cannabis Brownie Administration. The lead author was Matthew N. Newmeyer.
Basically this study was looking at how THC presents in blood and saliva after someone consumes an edible, and whether or not roadside screening devices can detect it.
They got a group of 16 volunteers to eat a brownie with 50.6mg of THC in it, and then they tested their blood and saliva over the next 48 hours. They use very sensitive lab tests as confirmation alongside the two roadside devices, the Draeger Drugtest 5000 (cutoff at 5ng/mL) and the Alere DDS2 (cutoff at 25ng/mL). The Draeger test is the one we are interested in because its the one used to confirm the result from the Drugwipe stick here in Australia.I say we're interested in the test, but really we're interested in knowing how long to wait before we will test clear.
They divided the group into 9 frequent smokers (most smoked daily) and 7 occasional smokers (2x per week). The frequent smokers had last smoked on average 9.5 hours before the test, whereas only one occasional smoker had smoked in the last 24 hours.
Basically, after accounting for the fact that the frequent smokers already had THC in their blood, the brownie dose affected the THC levels of all participants similarly (their blood and oral fluid levels, not subjective effects).
Here are some direct quotes from the bit about Oral Fluid Pharmacokinetics:
THC was detected in 5 (55.6%) frequent smokers (0.2-9.6ug/L) and no occasional smokers OF at baseline [before they ate brownies]
Peak OF THC concentrations were detected at first collection (0.33 hours) [20 min. The peak in blood came at between 1-3.5 hours for the frequent smokers and at between 1-5 hours]
THC was detected in frequent smokers' OF significantly longer ..than in occasional smokers'. At discharge (48h), 44.4% of frequent smokers were THC positive (0.3-2.6ug/L), while no occasional smoker was THC positive beyond 26h. [but that level is well below the Roadside DT cutoff]
With 1 and 2ug/L cutoffs, 100% of frequent smokers were THC-positive at 0.33h postdose, decreasing to 66.7% and 22.2% at 20h, and 11.1% (both cutoffs) at 48h, respectively; no occasional smoker was positive by 26h. With a 5ug/L cutoff, no frequent or occasional smoker was positive by 20 or 5h respectively.
So there is an interesting result. Remembering that 5ug/L = 5ng/mL, at that cutoff, 7 occasional smokers ate a 50.6mg brownie and after 5 hours, none tested positive in saliva (no mention of how impaired they looked or felt though.)
For the frequent smokers it took much longer for all to test negative.
Posted 11 May 2017 - 12:06 PM
So to summarize, the THC in oral fluid peaked at around 20 minutes after ingestion, then it went steadily down.
But the blood levels did not peak until between 1 and 5 hours later, then started to come down, meaning oral fluid THC was going down, even as blood levels were rising (!)
All the occasional smokers were clear of the 5ng/mL oral fluid test cutoff after 5 hours (but some may have been earlier). All the frequent smokers were clear of the 5ng/mL oral fluid test cutoff after 20 hours.
Another interesting thing to note is how high the peak in oral fluid was. For frequent smokers the median peak was 464ug/L with a range of (39.3 - 2111).
For occasional smokers the median peak was 392, with a range of (115 – 696).
Compare that to the peak in blood which ranged between 5.3-34.6ug/L for the frequent smokers and 3.2 - 14.3ug/L for the occasional smokers .
So what explains the wide ranges in the max OF THC and the difference between blood and saliva maxes? Was it previous smoking? Well, one of the occasional smokers had last smoked within 24 hours of the study beginning and all of the frequent smokers had too (with one particular guy having his last smoke only 40 minutes before going into the research facility. Poor dude probably needed to calm his nerves before eating a hash brownie for science! My money is on him being the one with the highest starting OF THC). However, as I said above, at baseline only half of frequent smokers and no occasional smokers tested positive in their OF.
I still think that oral contamination could be a big factor. The participants had 10 minutes to consume their brownie, and some may have chewed more than others, spreading the stuff around their mouths. I am just busting for someone to do a study on encapsulated THC to remove that variable!
Only 2 of the participants were women, aged 46 and 22 years. Both were in the occasional group. The rest were male between 19 – 40 years old.
This wasn’t a big or definitive study, but if you had to draw conclusions you could say that if you are a frequent male smoker who eats an 50mg edible, (and you refrain from smoking also), 20 hours is the minimum to wait to fall below the 5ng/mL cutoff.
If you are an occasional smoker (2x week or less) and you consume the same, you might be clear of the 5ng test after 5 hours – but, and this worries me, you might very well be at your most impaired around 5 hours as you experience your blood THC peak levels.
Now some people might think 50mg is a big dose, some a small one, but it is what it is. I’m also aware that in Australia one doesn’t stroll down to the dispensary to pick up edible products with THC% content neatly printed on the packet, but if you have some idea of the THC content of the strain you're using, you might be able to calculate roughly what your own edibles contain, and conservatively estimate THC and the time needed to sober up and test clear.
Posted 11 May 2017 - 04:46 PM
Thanks for posting that Billy E, some interesting stuff in there.
I think it's worth noting that in NSW at least, whilst in theory the Draeger machine is meant to be admissable in court blah blah, and if you pass it they let you drive away, if you sit the machine test because you failed the swab they send the swab off for lab testing. Now it doesn't matter if it's a false positive or not, the testing they do aims to find the slightest trace, and if it does your busted, as Jester found out the hard way. The law in NSW at least is very specific, it only requires you to have THC in your system, no matter how minor the level. So relying on the settings on the Draeger to cover your arse based on the above info is not all you have to worry about. This applies to all forms of consumption, so no matter how you do it there's an ongoing risk even if you know you're doing the right thing, which IMO sux big sweaty donkey balls.
Kinda hope that if our alleged medicinal cannabis legislation starts to become a reality, that they'll have to introduce a minimum level of THC in the blood for it to be an offence, but I'm not holding my breath.
"Not necessarily stoned, but ah beautiful" - Jimi Hendrix
"A long, long, long, long time ago, Before the wind, before the snow, Lived a man, lived a man I know, Lived a freak of nature named Sir Psycho." - RHCP
2012-2013 Outdoor grow - https://cannabis.com...tempt-nsw-aust/
2013-2014 Indoor/Outdoor grow - https://cannabis.com...indoor-outdoor/
2014-2015 Indoor/Outdoor grow - https://cannabis.com...ome-bean-trees/
2016 Indoor grow - https://cannabis.com...temple-of-hash/
Posted 12 May 2017 - 10:47 PM
Hi Sir Psycho, I fully, fully agree about.....that thing with the donkey. What happened to Jester - was s/he let go and then charged later?
I suppose I'm thinking that avoiding testing positive on the first screening is the goal, then you needn't be screened a second time on the Draeger.
The law in Vic is very similar. I did do some further research and had a chat with a courteous, helpful officer from Victoria Police highway patrol about what they currently do. He said that they used to use a machine similar to the Draeger, but no longer. He told me that in the case of a driver testing positive at the roadside, they would be taken back to the local station or drug bus for a second saliva test (with a similar test to the roadside swab. He was a little hazy on the details but kind of indicated that this involved putting a saliva sample in a solution of some kind, I'll see if i can confirm exactly what goes on). If the driver tested negative at the station, they would be free to go and not face future prosecution, however in all cases, both positive and negative, a saliva sample is sent to the Victorian Institute of Forensic Medicine for testing. He said that the police would receive a report indicating either that no THC was present, slight amounts, or that is was present; and only in the later case police would use this report to proceed with charges. He also indicated that unlike of roadside alcohol testing, a full certificate was not issued.
I'll try to find out the details of what goes on at the Victorian Institute of Forensic Medicine and post here.
Also I asked about how police decided who to test. He was quite upfront about the fact that the testing isn't random, or only partly so; for example, when they set up a drive though test site they might decided to test the first 8 people that come through for drugs, and after that they use their judgement, looking for obvious signs of impairment before drug testing. Slurred speech, unfocussed eyes etc. They get a positive result about 1 in12 times they test.
Out on the highway he said they wouldn't drug test everyone they stop, for example if they just pulled you over for a broken tail light. You'd always get breathalyzed though, which ties with my experience. Excessive speed (like 50+ over the limit) was a red flag for drug use, but I'd guess amphetamines usually. Really it was a pleasure talking to him, and when we were done he even wished me good luck with my paper or thesis!
Posted 26 May 2017 - 03:36 PM
Another update with some new details.
So I was able to find out more about what Vic. Police use for RDTs- the first test on the roadside is the Securetec Drugwipe Twin, and if you test positive here, you get tested in the bus or at the station with the Securetec Drugwipe Twin Combo, which is essentially the same test again, only with the capacity to collect extra samples - one of which goes to the Forensic Institute and one of which you get to take away to have privately tested if you wish.
The Drugwipe Twin or Twin Combo isn't for sale to the public, but it is apparently is basically the same as the Drugwipe 5S which you can buy.
As to the cutoff level, the Securetec website claims 5ng per mL for their new 2016 model, but its a bit more complicated than that. The new test claims to test for both Delta 9 THC and 11 Hydroxy THC which is the liver metabolite. An expert in the area told me that it is almost impossible (without an electronic test like the Draeger 5000) to test below 10ng per mL for Delta 9 THC, but it would be possible to test for 11 Hydroxy THC down to 5ng, so by including substance this they can claim the 5ng - a bit of tricky marketing.
According to the same expert, only a small amount of 11 OH THC returns to your saliva from the liver, around 5 to 25 percent. Now this information raises an interesting question: are the police using a new version of the Drugwipe Twin that also tests for 11 OH THC? Or will they be supplied with them in the future, even unknowlingly? I don't know, but 11 OH THC is not one of the prohibited substances that the Road Safety Act specifies. It specifically states only Delta 9 THC, so I would think that a test sensitive to 11 OH THC would not be permissible under the Act.
"prescribed illicit drug" means—
(a) methylamphetamine; or
(ab) 3, 4-Methylenedioxy- N -Methylamphetamine (MDMA);
It looks like 10ng per mL for Delta 9THC is the practical cutoff for the screening test - and the good news is that you can buy the Drugwipes to test yourself. The best price i can find is 49 dollars, which is the bad news. Nevertheless you're a regular smoker it might be worth buying a couple to see if you really are in the clear "the next morning". Be aware that dose and potency are apparently significant factors.
Also, I've been reading more interesting studies which I'll give the details for here. You can google up free online copies if you're in to this sort of thing. But basically I'm finding more evidence that THC does not transfer from blood to saliva well enough to show on saliva tests, unless the mouth is contaminated. And if you do eat a brownie and get cannabis chocolate crumbs around your mouth, the levels fall pretty rapidly. THCCOOH, the non psychoactive metabolite that stays in your system for a long time is another matter, but shouldn't be relevant for RDTs.
And for topicals, it seems even more unlikely that anything will reach your saliva.
Vandrey R. et al, Pharmacokinetic Profile of Oral Cannabis in Humans: Blood and Oral Fluid Disposition and Relation to Pharmacodynamic Outcomes (2017)
Lee, D and Huestis, M, Current Knowledge on Cannabinoids in Oral Fluid (2014)
Posted 10 June 2017 - 03:43 PM
I think if you vape regularly, the best thing would be to experiment yourself. Buy one of the securetec drugwipe tests and test yourself, say in the morning before you usually drive off to work or whatever. If you do it would be really interesting to hear your results.
You're right about THC being essentially water-insoluble, which is probably part of why it isn't readily secreted in saliva. But I unfortunately, I think what's happening when you smoke or vape or consume edibles (unless it something like canna caps) is that THC is just physically deposited in your mouth. Just like whatever else you put in your mouth, traces get stuck in the folds and wrinkles of your tongue, between your teeth etc. It doesn't need to be dissolved in your saliva to carry over onto a swab, it just floats along with the rest of breakfast or last night's dinner. The studies where participants ate brownies showed a peak in oral fluid THC right after eating, for everyone, including the non-frequent smokers. My theory is that that's because they had some crumbs and oil from the cakes in their mouth. In the study where they used encaspsulated THC, they didn't see the same peak in oral fluid.
So in theory, the more often you put THC in your mouth, and the higher the potency, the more plentiful the deposits. A daily smoker/vaper is always going to have some in their mouth. What I'm thinking is that the best way to keep your mouth clean would be to make canna caps with an extract (like a coconut oil infusion). It sounds a bit over the top, but you could use a delayed release capsule so that it is delivered straight to your small intestine, and even carefully put the filled capsule inside another bigger clean one to make 100% sure you weren't getting any oil in your mouth.
I had another thought today - if THC is readily soluble in oils and alcohol, then gargling and brushing your mouth with plain coconut oil or alcohol mouth wash would be more likely to remove deposited THC by dissolving it, vs rinsing and brushing with water, which is just a mechanical action. One of the studies I mentioned referred to substances that increased pH of oral fluid (like antacids) as interfering with saliva tests, so brushing your teeth with bicarb soda could be a helpful thing too.
Edited by billytheechidna, 10 June 2017 - 03:45 PM.
Posted 19 January 2018 - 04:14 AM
Hey mate. Would just like to thank you for going to great lengths to provide this information. I've read a lot over the past. Ethanol mouthwash, essential oil mouthwash, biotene, vinegar. All work in their own way. Swish some vinegar and notice 30 seconds later the amount of saliva in your mouth. Dilutes the sample, nothing to do with acidity, or how it's used to supposedly pass urine tests.
Anyway I signed up to thank you and point out we can possibly deduce the Police specifically still use the Drugwipe twin (over the 5s, 6s) solely due to the fact it doesn't detech 11 OH-THC! Whereas all the others do and therefore can't be used by Police.
I believe you are correct and 10mg/nl is their cutoff point, the 5ng/ml refers to the 11 oh-thc and is indeed a deceptive piece of marketing like you say. We can further deduce this to be the case if securetec currently have a test available in their brochure that doesn't test for 11 ohc, it would have to say 10ng. I bet the twin is the only one they still carry that doesn't test for 11 ohc and is thus 10ng not 5ng.
The twin are incredibly unreliable (false positives) and from what I've read the cut off is actually 20mg, unless they revised the twin in 2016 also (wouldn't it be called Twin II "S"?). It's hard to find any information on the twin as it's not available for public sale.
Edited by jonny77666, 19 January 2018 - 04:19 AM.
Posted 19 January 2018 - 02:08 PM
Ok found in Victoria it's 20ng/ml the first test (twin), 10ng/ml for the twin combo, and the laboratory test only shows positive for thc (not 11 oh thc) in amounts 15ng/ml>
The only thing I'm unsure about whether the first test is 10 or 12ng but it's most likely 20ng.
They're relatively reasonable. Shouldn't get charged after 4hrs of a smoke. Which is around the time or not long after the high is completely gone.
Edited by jonny77666, 19 January 2018 - 07:41 PM.