Can asthma medications cause a work-based positive drug screen?

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Asthma is a chronic lung disease that results in the inflammation and the narrowing of the airways. It is a highly prevalent disease with approximately 22 million sufferers in the U.S. alone. Of these 22 million, 6 million of them are children. Asthmatic individuals experiences recurring periods of wheezing, chest tightness, shortness of breath, and coughing. While these symptoms are not constant, they are very sporadic and can flare up at anytime. However, these symptoms are be effectively regulated by certain medications such as many steroid-based therapies. Since these medications tend to be steroid based, there is an association with asthma meds and positive drug screens. In fact, asthma medications have been shown to produce false-positive drug tests for amphetamines and ecstasy.

Drug testing by Employers

More and more employers are beginning to request drug screens for new and already employed workers. In fact, 80% of all large U.S. companies enforce drug screens and 40% of the work force within the U.S. has undergone a drug screen. Moreover, over 200 million Euros are spent on employer-based drug screens each year.

Most employers use external sources to complete these drug screens. These screens primarily consist of sending urine samples to a laboratory for analysis. Since instant test kits are now available on the market, results from these screens are usually available within 24 hours. More advanced laboratory test are used to confirm each positive drug test.

The majority of these screens consist of a five-panel test of the five most commonly abused street drugs: marijuana, cocaine, phencyclidine (PCP), opiates (including codeine and morphine) and amphetamines. Other employers may use a ten-panel test, which includes commonly abused prescription drugs. In addition, some employers also test for alcohol.

Since there is an association between asthma meds and positive drug screens and employers are implementing mandatory drug screens, it is important that employers are made aware of an employee’s asthmatic status.

What happens if an Employee Tests Positive?

The first step following a positive drug screen is to use extensive laboratory testing to confirm a positive test. Once the positive screen has been confirmed, it is than reported to an independent physician known as the Medical Review Officer. This physician will then contact the patient to determine whether there is a medical explanation for the positive screen, such as eating poppy seeds before the test (positive drug screen for opiates) or in our case, the use of asthma medications. However, physicians can use other tests to rule out a false-positive drug screens resulting from taking asthma medication. Therefore, drug abuser cannot rely on the association between asthma meds and positive drug screens as an excuse for testing positive for certain drugs.

In the case of a false-positive test, the patient will be tested once more within the near future to confirm their drug status.

If an employee tests positive, the employer must follow the policies and procedures they have put into place by the institute to determine the employee’s future within the company.

Benefits of Drug Testing

Since companies are investing their time and money into these drug screens, one may ask how these drug screens benefit the employer. U.S. studies have demonstrated that substance abusers are 33% less productive, 3 times more likely to be late for work and/or deadlines, 4 times as likely to be involved in an accident leading to injury of themselves or others, 5 times more likely ask employers for compensation following a work-related injury and 10 times as likely to miss work.

Moreover, the implementation of drug screens have been shown to decrease employee absenteeism by approximately 91%, supervisor problems and arguments by 88%, job-related accidents by 72%, job-related injuries by 97% and days lost to injuries by 80%.

The end product for employers is increased production and revenue. In fact, drug screen programs have been to have a benefit-cost ratio of 2. In other words, for every $100 invested in drug screens, an employer gains $200.

Reliability of Drug Screening

Like most medical tests, drug screens are not 100% accurate. The association between asthma meds and positive drug screens is just one example of the reliability of these screens. In fact, as much as approximately 30% of employer-based drug tests are considered to be false-positives. Moreover, urine drug screens are temporally limited. In that, the majority of casually-used drugs stay within the system for no more than 4 days. Another downfall to the urine screen is it is limited to measuring the metabolites of the drug and not the drug itself. Therefore, an employee can take drugs on their way to work and test negative because the drug had yet to metabolize. More expensive drug screens using hair follicles may be a more accurate screen for employers to use; in that the presence of a drug can be indentified for up to 30 days.

Considering that urine tests are only reliable at detecting drug use within a week or so and asthmatic patients commonly use their medications on a regular basis to avoid asthma attacks and symptoms, it is highly possible for asthmatic employees to test positive. Therefore, it is important that employers are made aware of an employee’s medical history and medication use.


National Heart and Lung Association -

The Lectric Law Library -

Global Change -

National Health Institute -

Pre-employment Drug Screening -