Published: 1 September 2016

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Medicines can Impair Driving

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Prescriber Update 37(3): 45
September 2016

It is against the law to drive while impaired. The Land Transport Amendment Act 2009 states that it is an offence to drive while impaired and with evidence in the bloodstream of a qualifying drug¹. Qualifying drugs include controlled drugs and prescription medicines. Further information on the legislation is available at www.transport.govt.nz/legislation/acts/QAsdrugimpaireddrivinglaw

Healthcare professionals can assist their patients by informing them of the potential impairing effects of medicines (this includes over-the-counter and pharmacist-only medicines as well as prescription medicines). Medicines with the potential to impair driving ability include some pain relievers, anxiolytics, antidepressants, sleeping aids, antiepileptics, sedating antihistamines, antipsychotics, medicines used in the eyes, cough and cold medicines and some heart medicines².

Not every medicine within each medicine class will impair driving nor cause impairment in every person. However, patients should be informed of the potential risk. Additionally, it is important for patients to continue treatment as some conditions requiring medical treatment may themselves affect driving ability if left untreated³.

Symptoms of impairment include dizziness, drowsiness, headache, nausea, blurred vision, slowed reactions, inability to focus, being easily confused, slurred speech and feeling manic or overconfident². Importantly, the patient may not always be aware that they are impaired and impairment may continue the following day (eg, zopiclone and next-day impairment, see the Prescriber Update article for more information www.medsafe.govt.nz/profs/PUArticles/June2014ZopicloneAndNextDayImpairment.htm).

Further guidance to patients could include:^2,3

• not driving until the patient knows how the medicine affects them
• avoiding driving completely, particularly during treatment of a short-term condition
• not driving if the patient experiences any symptoms as described above
• considering alternative options, such as a different medicine or if it can be taken at a different time of day.

Please note that this information is advisory only. Data sheets for individual medicines should be checked for information on possible driving effects. Medicine data sheets are available at www.medsafe.govt.nz/Medicines/infoSearch.asp

References

1. Land Transport Amendment Act 2009. URL: www.legislation.govt.nz/act/public/2009/0017/40.0/DLM2014902.html (accessed 11 July 2016).
2. NZ Transport Agency. Are you safe to drive? URL: www.nzta.govt.nz/safety/driving-safely/medication/are-you-safe-to-drive/ (accessed 11 July 2016).
3. Medicine and Healthcare product Regulatory Agency (MHRA). Drug Safety Update - Drugs and driving: blood concentration limits set for certain drugs. 16 February 2015. URL: www.gov.uk/drug-safety-update/drugs-and-driving-blood-concentration-limits-set-for-certain-drugs (accessed 11 July 2016).