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jd8770 · Jul 4, 2012, 01:59 PM

If a 250lb male consumed 375ml of 80% alcohol on a Friday, time frame 6pm to 12 am, would he be positive on a Peth test at 3pm Monday? I have studied the references and am confused. One says 50g a day for say, a week, could test positive 14 days after last drink. Another found a "bolus" of 100 grams pure alcohol on one day could be detected 14 days later. Which is it or is it both?

DrBill100 · Jul 4, 2012, 03:28 PM

You are not the only one confused by the studies on PEth. The ambiguous findings that you note are basically where the research stands.

When PEth results it is detectable for an extended period. That much is agreed upon. The induction threshold is far less clear.

USDTL Lab estimates it requires approximately 200g cumulative consumption across a period. Gnann, etal indicates ~50g per day across a two week period but also states a single binge could have the same result. That figure is not quantified.

Dr Greg Skipper, who recommends PEth as complementary to EtG states that it becomes positive after 7 drinks. An earlier study, Aradottir (2006) indicated a daily intake of 48-102g daily for 18 days was required. Zyeng (2011) also noted that sustained consumption was required. Another study, that I can't locate at the moment, clearly states that a single binge episode would not show PEth positive. I believe it was either Helander or Hoiseth but don't know for sure.

It is my opinion that the science on this biomarker is infirm and experimental and another example of foisting a test on the marketplace as established well in advance of it's proven efficacy.

Wish I could be more helpful but the information simply isn't there.

You're just above the supposed threshold of 7 drinks (8.5) so your size and/or metabolism may make the difference. There is a wide inter-individual variation in the results.

Who is doing the test? It is a pain to administer and has to be shipped frozen.

jd8770 · Jul 4, 2012, 04:41 PM

It's the USDTL lab and it's a bloodspot test. Isn't 8.5 drinks only 120 grams of alcohol? The lab says 200 grams is the trip point. Are you assuming two Fridays and then a test within 14 days of last drink? The induction period is vexing. Also, the blood is taken and blotted on the paper and then shipped out of state. Does the blotted paper have to be shipped frozen? By the way, thanks for the references. There was one I hadn't found.

DrBill100 · Jul 4, 2012, 04:52 PM

Originally Posted by jd8770

It's the USDTL lab and it's a bloodspot test. Isn't 8.5 drinks only 120 grams of alcohol? The lab says 200 grams is the trip point. Are you assuming two Fridays and then a test within 14 days of last drink? The induction period is vexing. Also, the blood is taken and blotted on the paper and then shipped out of state. Does the blotted paper have to be shipped frozen? By the way, thanks for the references. There was one I hadn't found.

No the blood spot is shipped in an envelope by regular mail. It is a unique idea and USDTL is the only one using. Here is a video from Doug Lewis, Pres of USDTL on PEth: Why test for PEth in blood? - YouTube

You're right your actual consumption was 119g pure alcohol.

Bear in mind this is a new technology and neither the time lines or quantities are firm. In addition, a drink is not a good reference point. It is better to calculate the intake as grams of alcohol per kilogram of body weight. Give me your height and I'll figure for you. Also the time from first drink until last and any food intake during that period.

jd8770 · Jul 4, 2012, 06:58 PM

Ht. 5'11" consumed 6 pm to 12am Friday. Had an average hamburger about 9the pm.

DrBill100 · Jul 4, 2012, 07:28 PM

Given the rate of consumption your BAC should never have exceeded .07. BAC it would seem to me to be important because it is the presence of EtOH in your blood that perturbs red blood cells leading to PEth response. That's just a guess as there is no research dealing with the subject.

I was just going over the latest SAMHSA release on the subject of biomarkers and they note "There is still little research on PEth, which is only beginning to be studied by researchers in alcohol studies." p. 3 Advisory, 2012.

So as I noted above this is a test that has been rushed into the marketplace without adequate research and documentation just like EtG before it. USDTL is the only lab offering dried blood spot testing. That is neither here nor there because it doesn't add to the predictability of your situation.

Don't believe we got much further than when we started. I still don't know the answer and don't believe it is to be found.

Hope you'll let me know the results.

jd8770 · Jul 4, 2012, 09:11 PM

No test anticipated. I am just really find this whole idea of using these tests that can make a huge difference in a person's life. Obviously there are many ways to look at this from a recovery standpoint, but I still like to know what I'm dealing with. I will keep you posted good or bad. Thanks so much for the insights.

mcummings1967 · Mar 18, 2013, 07:27 PM

Originally Posted by jd8770

No test anticipated. I am just really find this whole idea of using these tests that can make a huge difference in a person's life. Obviously there are many ways to look at this from a recovery standpoint, but I still like to know what I'm dealing with. I will keep you posted good or bad. Thanks so much for the insights.

I know this is an old response but I am curious if you found anything more.

My Healthcare license was pulled due to a positive test peth.

I have not ingested alcohol since June 2012 almost a year.

Looking for anything my life is turned upside down and inside out!

Thank you