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Cold and Flu Medications – Implications for workplace drug testing

Updated: Apr 12

Cold and Flu Medications – Implications for workplace drug testing

The cold and flu season is fast approaching. According to a report, 300,000 Australians were struck by influenza last year and forecasts predict the 2024 cold and flu season to be as bad as, if not worse, than 2023. Supporting that notion, Victorian health services have recorded 5200 flu cases so far this year, 1300 more than this time last year.

The most effective way of avoiding the severe effects of the flu is by yearly flu vaccinations. For colds, the recommended treatment is rest and fluids. However many workers will try to alleviate the symptoms with a range of medications. And that can be a problem. That’s because some cold and flu medications have potential side effects, such as drowsiness, light-headedness and dizziness that can impair a worker’s performance. Some medications can also produce a positive result in a workplace drug test. Let’s revisit the drugs commonly found in our everyday cold and flu medications and what they mean for workplaces.

  • Pseudoephedrine: It is included in cold and flu medications as a decongestant. Related side effects such as nausea, dizziness and insomnia1 can adversely affect safe work performance. The purchase of medications containing pseudoephedrine requires the presentation of a photo ID. This is because pseudoephedrine is a precursor in the manufacture of illegal amphetamines. As such, it may produce a positive result for amphetamines in a workplace drug test.

  • Phenylephrine: Also a decongestant and while it may not be quite as effective as pseudoephedrine, it does not have the significant side effects and can be purchased off the shelf under the label, “PE”. Phenylephrine will not produce a positive result in a workplace drug screening test.

  • Antihistamine: People taking sedating antihistamines, such as dexchlorpheniramine, diphenhydramine, doxylamine and promethazine, often don’t feel sleepy but have trouble staying awake and their brain function is impaired. With sedating antihistamine use, there is an increased risk of traumatic work-related injuries, driving accidents and aviation fatalities. They are frequently a causal factor in fatal traffic accidents 2 but will not be picked up in a workplace drug test.

  • Pholcodine: Products containing pholcodine can no longer be sold in Australia due to safety reasons. The Therapeutic Goods Administration (TGA) recall set 8th March 2023 as the deadline for pharmacies to remove all cough medicines and lozenges containing pholcodine from their shelves. However, due to their widespread use, it is likely workers may still have products containing pholcodine at home Pholcoldine can produce a positive result in a workplace drug test.

When it comes to cold and flu medications at work, our best advice is that workers always consult their health professional as to the most appropriate treatment for their symptoms, considering the implications for the work activities they perform.

If your workplace conducts drug and alcohol testing, it is important that your workers understand that some cold and flu medications can trigger a positive drug test result.

Raising awareness of the potential impact of cold and flu medications on workplace safety, and highlighting the alternative medications that are available, is an important discussion at this time of year. Such communication should also include the potential effects of impairing medications not included in drug testing.

DASA can help with training and education around cold and flu medication. For more information, get in touch via: or call us on 1300 230 231.

If you are interested in knowing more about cold and flu medications, check out our webinar on “Safe and Effective use of Cough & Cold Medications” or previous blogs listed below.


DASA (Drug and Alcohol Solutions Australia) is proud to be leading the way in workplace drug and alcohol testing services throughout Australia. Whether your need is for workplace drug and workplace alcohol testing, advice on drug and alcohol policy or ideas on how to communicate your workplace expectations, policies and procedures to your staff, DASA can help. We have the experience, technical expertise and people to lead you to the right solution.



2 Kay GG, Quig ME. Impact of sedating antihistamines on safety and productivity. Allergy Asthma Proc. 2001 Sep-Oct;22(5):281-3 PMID: 11715216.


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