Psychoactive drugs and driving

Abstract

Any drug or substance with effects on the central nervous system can impair the ability to drive safely.When prescribing, consider the effects of each drug on driving as well as the use of other substances. Advise the patient of the risks.Opioids, benzodiazepines, anticonvulsants, antipsychotics and sedating antidepressants increase the risk of crashing. Erratic use of sedatives causes a higher level of impairment than stable regimens.Patients who have complex medical conditions and take multiple drugs should undergo a fitnessto-drive assessment. Random testingAt present, random roadside alcohol and drug testing occurs to a variable extent throughout Australia. Alcohol testing involves a screening breath analysis followed by confirmatory testing with highly sensitive and specific instruments. When a confirmatory sample cannot be obtained, blood testing may be required.Random roadside samples of saliva are tested for three substances:• delta-9-tetrahydrocannabinol (cannabis)• methamphetamine (commonly known as ice or speed)• 3,4-methylenedioxymethylamphetamine (MDMA, commonly known as ecstasy).These drugs were originally selected to avoid legal defences based on prescribed medicines. Screening is done at the roadside with an oral wipe. If the result is positive, an oral fluid sample is taken and sent for confirmatory testing. Cut-off concentrations for driving offences are set according to the Australian Standard (AS/NZS 4760-2019) or local policies. Mandatory testingMandatory testing is required following a motor vehicle collision. Blood, and in some jurisdictions, urine, is collected. Samples are screened for commonly used substances including alcohol. If there is a positive indication, confirmatory tests are carried out. Observation of impaired driving behaviour in conjunction with blood sampling is generally required to prove the offence of driving under the influence, particularly for prescription drugs. Drug concentrations on their own do not predict individual driving ability due to the user developing tolerance to the drug.

Consequences of COVID-19 Lockdown on the Misuse and Marketing of Addictive Substances and New Psychoactive Substances

“…Besides, the anti-COVID-19 restrictive measures modified the drug offer and altered substance misuse patterns. Drug-related phenomena like the drugs-and driving and drug parties are expected to decrease (17,18). Due to high addiction liability, we suppose that the global shortage of heroin may have forced regular users to take other substances with similar effects, such as fentanyl analogs.…”

Medicines and driving in older people

“…These are often used in combination with alcohol by people of all ages. 17 Polypharmacy (taking five or more unique medicines daily) is an alert for possible driving impairment risk. 15 An analysis of Australian Pharmaceutical Benefits Scheme dispensing data found that between 2006 and 2017 the prevalence of taking five or more medicines increased from 33 to 36% in Australians aged 70 years and over.…”

“…[19][20][21] Other ways that medicines may adversely affect driving are effects on balance, vision, judgement, aggression, risk-taking, psychomotor coordination, vigilance and attention. 10,17,[19][20][21] The issue is further complicated by road users omitting to take prescribed medication, doubling up (e.g. due to confusion with generic medicines), taking medicines at inappropriate times, taking alcohol with medicines, or taking additional non-prescription medicines or complementary medicines and then driving, oblivious to potential dangers.…”

“…The level of medicine which will remain in a person's system over time depends on a range of factors including the quality and quantity of the medicine, if it was taken in combination with other medicines, illicit drugs, and/or alcohol, and the individual's metabolism. 3,17,22 Random Roadside Drug and Alcohol Testing At present, random roadside alcohol and drug testing, plus blood testing, when necessary, occurs to a variable extent throughout Australia. Random roadside samples of saliva are tested for three substances: delta-9tetrahydrocannabinol (cannabis), methamphetamine (ice or speed), 3,4-methylenedioxymethylamphetamine (MDMA, commonly known as ecstasy).…”

“…Alcohol continues to be the most prevalent drug causing road trauma although driving under the influence of drugs is increasing. 17 In Australia, the prevalence of alcohol in road fatalities was 30%, based on data published in 2016. 24 Figures from 2007-2013 showed 23.6% of drivers killed on Australian roads had a blood alcohol content exceeding the legal limit.…”