What medications can cause a positive alcohol test?

Here, we explore alcohol testing in more detail, including the different types of alcohol test available, and everyday items/medications that have the potential to impact the results.

Read the full article below.

What is alcohol testing?

Alcohol testing is the analysis of one or multiple sample types from an individual to look for the presence of alcohol or alcohol biomarkers.

The type of alcohol test used depends on what needs to be determined. Some tests are better for identifying very recent use (breath alcohol testing) or for monitoring alcohol misuse/consumption in real time (SCRAM CAM®).

Others can be used to identify a pattern of chronic & excessive alcohol use or abstinence over several weeks or months, providing even greater insight into a person’s drinking habits (hair, nail and blood alcohol tests).

What type of alcohol tests are there?

There are several ways that alcohol misuse can be detected and measured, depending on the sample type available. In this section, we look at some of the different alcohol tests available.

Hair Alcohol Testing

There are two main biomarkers of alcohol that can be tested for in hair.

Ethyl Glucuronide (EtG) is water soluble, produced in the liver, and is deposited onto your hair via sweat glands. Hair treatments such as bleaching, dyeing, perming, straightening, and excessive washing all have the potential to reduce the levels of EtG found on the hair.

Ethyl Palmitate (EtPa), a fatty acid ethyl ester (FAEE) is lipophilic (fat soluble). This means that styling methods such as bleaching, perming, dyeing etc. will not significantly affect EtPa levels unless there has been aggressive use of these products. However, styling products that contain alcohol (hairspray, gel, wax) can increase the levels of EtPa found during laboratory analysis.

Sample donors are advised not to use any alcohol-based styling products for at least one month prior to testing, to reduce the likelihood of an elevated EtPa result.

EtG and EtPa tests can be used to determine chronic & excessive alcohol consumption – or EtG only for abstinence – over a period of up to approximately 12 months, depending on the length of hair available for testing.

Because of their respective strengths and weaknesses, both EtG and EtPa tests should be performed, and their findings used to support each other. Performing hair alcohol testing in conjunction with Phosphatidylethanol (PEth) blood alcohol testing and other blood tests, can also allow an even more holistic conclusion to be drawn about a person’s alcohol use.

Learn more: Hair Alcohol Testing

Nail Alcohol Testing

Nail alcohol testing is ideal for circumstances where hair testing is not possible, such as where the donor has little or no head hair, if they are unable to provide a hair sample for cultural/religious reasons, or where adulteration of hair samples is suspected (e.g. excessive bleaching, dyeing, perming, straightening or washing).

The test works by analysing fingernail clippings or toenail clippings for the presence of Ethyl Glucuronide (EtG), which is a direct biomarker of alcohol, and can be used to detect chronic & excessive alcohol consumption or abstinence.

It is also highly effective when used alongside other alcohol testing methods, such as blood alcohol testing, helping to build a multi-source profile of alcohol use.

Fingernail clippings provide an overview detection window of up to approximately 6 months, while toenail clippings provide an overview detection window of up to approximately 12 months. This is because fingernails and toenails grow at different rates.

Learn more: Nail Alcohol Testing for legal & official purposes
Learn more: Home Drug & Alcohol Nail Test

Blood Alcohol Testing

There are several blood tests available to detect alcohol consumption.

Alcohol in the blood can be detected for around 12 hours after your last drink. A simple blood alcohol test is sometimes used if an offender is caught drink-driving and meets the criteria for a blood test. This type of test will only tell you how much alcohol is circulating in the blood at the time of test.

Other types of blood alcohol test – like the ones we offer at AlphaBiolabs – can be used to monitor chronic & excessive alcohol consumption or abstinence over a longer period.

Blood alcohol tests we offer at AlphaBiolabs include:

• Phosphatidylethanol (PEth) testing – the gold standard of blood alcohol tests. PEth is a direct biomarker of alcohol, meaning that it is only present in the body when alcohol has been consumed. The test can be used to detect chronic & excessive alcohol consumption, to monitor drinking behaviour/abstinence and to identify relapse. The test is so sensitive that it can even be used to detect single-drinking episodes.

  Detection window: Up to approximately 4 weeks

  Learn more: PEth Alcohol Testing

• Carbohydrate Deficient Transferrin (CDT) testing – second only to PEth for its accuracy and reliability. Transferrin is a protein largely made in the liver that regulates an individual’s iron absorption into the blood. Alcohol consumption can significantly impact the levels of carbohydrate deficient transferrin in the blood, meaning laboratory analysis can be used to measure these levels and draw a conclusion about alcohol use over a defined period.

  Detection window: Up to approximately 1-month

• Liver Function Test (LFT) – used to determine the health of the liver by measuring certain enzymes and proteins created by the liver and found in the blood. Alcohol can be toxic to the liver, meaning that a person who consumes excessive amounts of alcohol will damage this vital organ and may experience reduced liver function.

  An LFT measures three enzymes in the blood to assess liver damage: aspartate transaminase (AST), alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT).

  Detection window: Snapshot of liver function at the time of the test

• Mean Corpuscular Volume (MCV) test – used to measure the average size of red blood cells in a blood sample. Red blood cells play a vital role in the function of organs and tissues, carrying oxygen in the blood to all parts of the body. If the MCV marker in the blood is higher than normal, this can indicate enlarged red blood cells and, in turn, chronic and excessive alcohol consumption.

  Detection window: Up to approximately 4 months

Unlike PEth, CDT, LFT and MCV are all indirect biomarkers of alcohol, meaning that their levels in the body can be impacted by other factors besides alcohol consumption, such as underlying medical conditions.

For this reason, it is recommended that CDT, LFT and MCV be used to complement PEth testing and other alcohol tests (e.g. hair alcohol tests), for the most conclusive insights.

Learn more: Blood Alcohol Testing

Breath Alcohol Testing

Breath alcohol testing, performed using handheld breathalyser devices, can be used to detect alcohol consumption for up to 24 hours after the person last consumed alcohol.    

For a breath alcohol test, the sample donor is asked to blow into a disposable mouthpiece attached to the breathalyser device. The device then measures the person’s breath alcohol concentration (BrAC) – the level of alcohol present in their breath at the time of the test – providing an immediate result.

Breathalysers are commonly used:

• By police for roadside drink-driving checks
• By social workers for point-of-care testing in child welfare matters
• Where routine testing is required to ensure compliance with court orders, including during child welfare and custody cases where a parent or caregiver must demonstrate sobriety
• By employers conducting random or for cause/post-incident alcohol screenings

Learn more: Breath Alcohol Testing

SCRAM Continuous Alcohol Monitoring (CAM)^®

SCRAM CAM® is an alcohol monitoring bracelet worn around the ankle, that uses 24/7 transdermal analysis to detect traces of alcohol in sweat.

The device takes readings every 30 minutes, can register very low levels of alcohol consumption, and can even distinguish between active drinking and environmental exposure to alcohol.

SCRAM CAM® can be worn for as long as the instructing party requires and can be used on its own or in conjunction with other forms of alcohol testing to monitor ongoing alcohol misuse or abstinence. It is often used to support treatment and enhance supervision for:

• Domestic violence cases, where alcohol is a contributing factor
• Drug users, who often turn to alcohol once they are actively being tested for drugs
• Individuals with alcohol-dependency issues
• Family law courts, to assess the level of a parent’s alcohol problem, or gather evidence to support acceptable drinking behaviours
• Custody conditions or child visitation arrangements

Learn more: SCRAM CAM^®

What medications can cause false positive alcohol test results?

While false positive alcohol readings are extremely rare, they can sometimes happen.

Alcohol is found in things other than your favourite tipple, such as mouthwash, hand sanitiser or even some medications. 

If you need to prove abstinence, or show that you do not drink excessively, you should consider taking a test that covers multiple markers and sample types, as this will eliminate the chances of you obtaining a false positive result. 

At AlphaBiolabs, we offer a combined blood and hair alcohol testing package, giving you complete insight into someone’s alcohol use. 

Let’s look at some everyday items which contain alcohol. 

Over the counter medications

Over the counter (OTC) medications are medicines which don’t require a prescription from the doctor. 

Some medications, both over the counter and prescribed, contain small amounts of alcohol. 

When you take these medicines, particularly if you need to take the maximum dose, some of the alcohol will circulate in your blood. 

Some people buy certain OTC medicines to abuse them because of their alcohol content. Whilst some prescribed medications also contain alcohol, they can only be obtained through a prescription and so are harder to obtain.

Why is alcohol in medicines at all? Depending on the medicine, alcohol might be used as a preservative or as an active ingredient. You’re more likely to find higher alcohol concentrations in liquid medicines. 

Some medicines that contain alcohol include:

• Some cough medicines (e.g. Sudafed)
• Some cold and flu medicines (e.g. Tylenol)
• Some allergy medications (e.g. Benedryl)
• Vicks

If you need to take medicines that contain alcohol, you should avoid having alcoholic drinks at the same time. Not only will the dual consumption of alcohol increase your blood alcohol content (BAC), but some medications can interact badly with alcohol and can have serious consequences. 

Asthma medications

Asthma is a condition that causing breathing difficulties. It’s relatively common and is usually treated with steroid inhalers. 

Some steroid inhalers contain alcohol. One example is beclomethasone inhalers. 

Alcohol is sometimes used in inhalers because it increases the solubility of the active ingredient. This helps it to work faster and more effectively. 

As the delivery method involves you breathing the medicine into your lungs, there is a small chance that you may get a slightly higher breath alcohol content (BrAC) reading from a breathalyser. 

Mouthwash

Alcohol is usually present in mouthwash. 

Depending on the brand, alcohol may be used to make the ingredients more soluble. 

The alcohol that remains in the mouth after you spit the mouthwash out can potentially lead to false positive results from a breath or saliva test.

Oral gels

Some oral gels like the ones used to treat mouth ulcers may contain a very small amount of alcohol.

How can I avoid false positive alcohol test results?

Despite the presence of alcohol in the medications listed above, getting a false positive on an alcohol test is extremely rare, as you should not be consuming these products in the same quantity as you would an alcoholic drink, and the alcohol levels will also be significantly lower than those contained in alcoholic drinks.

However, if you are required to submit a sample of any kind for an alcohol test, you should always tell the sample collector if you have recently used any medicine or products that contain alcohol. 

The sample collector will gather this information and it will be factored into the results to ensure that they are a true reflection of your recent or past alcohol consumption. 

Unless you are abusing over the counter medicines or alcohol-containing products, a breathalyser is extremely unlikely to give a reading that is indicative of intoxication, and other tests for longer-term alcohol use will not indicate excessive or chronic use.

Where can I get an alcohol test?

AlphaBiolabs is one of Ireland’s leading providers of laboratory alcohol testing services for members of the public, the legal sector, and the workplace sector.

Our accredited laboratory can test a variety of samples for the presence of alcohol and its metabolites, including breath, blood, hair, and nails.

We also offer alcohol monitoring in the form of SCRAM Continuous Alcohol Monitoring®.

To discuss your alcohol testing needs, call our Customer Services team on 01 402 9466 or email info@alphabiolabs.ie.