The PEth test: the importance of Phosphatidylethanol (PEth) in driving tests

Individuals seeking a review or lifting of a driving ban must add supporting documents to their file. Phosphatidylethanol (PEth) test results play a crucial role here.

PEth provides an indication of alcohol use in the past month, while alcohol itself is detectable only up to 10-12 hours after ingestion. Regular PEth testing can help demonstrate long-term abstinence, which is relevant for driving tests.

In addition to drunk driving, there are other legal situations in which the PEth test can be useful. Consider, for example:

• Family law cases: In custody cases as evidence of a parent controlling his or her alcohol use.
• Employment law cases: Employees who have lost their jobs because of alcohol-related problems.
• Criminal cases: Demonstrating a change in alcohol consumption may affect sentencing.

• Sample collection is always performed under supervision by experienced AZ Delta medical staff and always unambiguously identified.
• PEth and alcohol are tested in the blood at the same time.
• Testing frequency is weekly. Make an appointment online here.
• Results are delivered digitally via secure email within 8 working days.
• The cost is 150 euros (including VAT).

PEth consists of a group of compounds of phospholipids with ethanol formed in red blood cells under the influence of the enzyme phospholipase D.

The enzyme phospholipase D has multiple isoforms with different pharmacokinetics. There are about 50 PEth phospholipid homologs with variable length and saturation. PEth 16:0/18:1 is the most prominent at 37% and is measured for that reason.

PEth is only present in the blood after alcohol consumption. It has a half-life (the time required for half of a given substance to break down) of 4-10 days, but varies widely among different individuals.

After 1 alcohol consumption, PEth can be detected 1 to 2 hours later. With regular alcohol consumption, it accumulates in red blood cells.

Although CDT (Carbohydrate-Deficient Transferrin) has long been used as a biomarker for long-term alcohol consumption, Phosphatidylethanol (PEth) has increasingly proven to be a superior indicator. Here are some reasons why PEth is often preferred to CDT:

1. More sensitive to short-term and moderate alcohol consumption: PEth can be detected even after a single alcohol intake, whereas CDT will be elevated only with long-term and heavy alcohol consumption (>50-80 g/day for 1-2 weeks).
2. Longer detection period: while CDT normalizes after 2-3 weeks of abstinence, PEth has a longer half-life and can demonstrate total abstinence from alcohol for a longer period (1 month on average).
3. Less influenced by other factors: CDT is not a good marker for individuals with liver disease or certain genetic transferrin variants. PEth is less influenced by these.
4. Objective measurement: PEth tests provide an objective measurement of actual alcohol use, whereas CDT tests can provide “false negative” results. A “normal” CDT is not probative of abstinence or absence of problematic alcohol use.
5. Better correlation with alcohol intake: PEth has a direct relationship with the amount of alcohol ingested, making it a more reliable indicator of actual alcohol consumption. PEth is a much better marker to demonstrate moderate to intermittent alcohol intake.

The PEth test not only provides a valuable tool for restoring driving privileges, but also has broad applications in various legal contexts.

Through reliable and objective measurements, it can help demonstrate alcohol abstinence and influence decision-making in legal matters.

Do you have questions about the PEth test? Please do not hesitate to contact us via our contact form or call 051/920.911