OPINION

Six weeks ago I had a knee replacement. The operation had been lined up for 16 months earlier, but the surgeon had some health issues and he has only now got back to work.

Both knees are done now and I’m looking forward to a pain-free future. The first game of bowls is this week, so things are progressing well.

I was sent home with a bag of drugs. Antibiotics just in case of infection, anti-inflammatories as well, along with three different painkillers based on expected levels of pain at various stages.

They say that the pain of knee replacement is worse than childbirth, but it is hard to imagine that.

The pain is not excruciating, but with increased activity, it does hang around for a while. However, with the increased activity, you feel more capable and I was physically able to drive.

What held me back though, was trying to understand what level of pain relief makes you potentially impaired while driving, and it is very difficult to find that out.

Drugged driving has long been a problem that has been challenging to tie down, most particularly when the drugs involved are prescribed by a doctor and dispensed by a pharmacist with no clear alerts.

In my case, the more potent drugs had warnings that identified that “this medicine may make you sleepy and make it dangerous to drive or operate machinery – limit alcohol intake.”

That is a precautionary signal which doesn’t make it illegal to drive. There is a clear message that the consumption of alcohol while on prescription drugs is just not smart.

From April next year, the police will have the authority and the tools to be able to randomly roadside test via a saliva sample for the presence of the 25 most common drugs which could be in a driver’s system.

The bulk of these will be prescription medications. You’d like to think that the real target for this testing is illegal and recreational drugs such as cannabis, MDMA (ecstasy), and methamphetamine. These are well-known problem drugs, most particularly when mixed with alcohol.

The thing with random roadside testing for these problem drugs is that they are illegal, and the law, as it stands, confirms that any confirmed presence of these drugs in a person’s system while driving is an automatic conviction.

The research is sparse about what level of presence makes the driver impaired, but the law says it doesn’t matter – any level is illegal.

The research is conclusive, though, that the presence of alcohol in combination with these drugs multiplies the level of impairment. This makes conviction appropriate, even though the driver’s alcohol level might be below the legal limit.

The zero tolerance for illicit drugs sends a clear signal that these drugs and driving are incompatible.

But where does this leave the driver who has taken appropriately prescribed medications, without the presence of alcohol, but with no particular knowledge of how impaired they might be, other than a heavily qualified label on their medication?

We have a vast knowledge gap here, which the police will need to have some discretion about whilst roadside testing.

There’s no doubt that certain prescribed drugs at certain levels can cause driving problems, and they can be scary stuff.

In fact, one of the biggest public health issues in the US is the opioid accidental death epidemic. People taking prescribed medications, ostensibly for pain but actually to get high, have caused over 600,000 premature deaths over the past twenty years through overdose.

A 2013 report called the “Wolff Report on Driving Under the Influence of Drugs” has endeavoured to categorise the range of painkillers, anti-depressants and sedatives as to the level of potency and at what level driving impairment might occur.

This is an attempt to give guidance to authorities about legal limits. Fentanyl, incidentally, is regarded as 80 times more potent than morphine, and great care is needed with its prescription.

Random roadside drug testing is an extra tool in the toolbox to make our roads safer.

Common sense along with better education and knowledge in respect to prescription drugs, especially mixed with alcohol, are also crucial parts of that mix.