Following the Boxing Day crash near Bendalong that killed five people, including one of the drivers who had just been treated at a Nowra methadone clinic, Kiama MP Gareth Ward wrote to the attorney general and roads minister to lobby government for stricter laws on driving under the influence of methadone.

”It’s illegal to drive with methadone in your system in the UK,” Mr Ward said.

“It should be on the banned substance list here, it affects cognitive function.”

An addiction medicine specialist does not agree with Mr Ward.

“There is no sound evidence to ban all methadone patients from driving - indeed that would be counterproductive for community safety,” University of Sydney addiction medicine specialist Nicholas Lintzeris said.

“Would we rather we had people not in treatment and injecting heroin and driving?

“For people in rural or regional areas where there is inconsistent public transport, a driving ban for all patients would mean many would have to drop out of treatment.

“This ultimately harms the patients, their families and the community.

“The actions of a few patients should not be generalised to all people with a health condition, and only serves to stigmatise people.”

Mr Lintzeris said methadone, like all opioid medications, causes minimal impairment for most patients once they have stabilised on their dose.

“As with all prescription drugs, patients are advised not to drive if the medication affects them - such as drowsiness, sedation,” he said.

“As with all medications - this is more likely to occur if taking multiple medicines, tiredness, alcohol etc, but there is nothing unique about methadone.”