New roadside drug testing law sees Cannabis Clinic backing patients

Aotearoa's leading medicinal cannabis prescriber, Cannabis Clinic, is standing by patients ahead of the new roadside drug testing law coming into effect. Random roadside saliva drug testing is scheduled to begin in Wellington from the 15th of December 2025, with nationwide coverage expected by mid-2026.

The tests will screen four key drugs: methamphetamine, MDMA or ecstasy, cocaine, and THC, which is found in cannabis. Under the Land Transport (Drug Driving) Amendment Act 2025, the decision aims to improve the safety of Aotearoa's roads.

Cannabis Clinic CEO, Dr Waseem Alzaher, appreciates the sentiment behind the new law, but believes these tests will not reliably assess impairment.

"Global evidence shows that the proposed legislation is not fit for purpose or shown to make our roads safer from a THC perspective, and we voiced this in our submission to the Transport and Infrastructure Select Committee last year," he says.

"It's widely understood that saliva tests can detect drugs long after they've been used and long after someone is impaired by them. Unlike alcohol, where its presence in your blood or breath directly correlates to levels of intoxication, a medicine or drug can be detected in your saliva long after its effects have worn off. And depending on the medication and THC dose, there's scientific evidence that many medicinal cannabis patients are not impaired, even immediately after taking it as prescribed."

The rollout of the new law means that Kiwis taking legal medicinal cannabis products under medical supervision are at risk of suspension of their licence, fines, demerit points, or other legal consequences. In the immediate instance, if a saliva test is positive with one or more drugs detected, the person will be asked to take a second saliva test. If this also tests positive, they will be barred from driving for 12 hours.

Under the legislation, individuals who return a positive lab test, blood test, or test positive for THC in a roadside saliva test twice in two years, and do not have a medical defence, could face more serious legal consequences.

Details on the testing device and their sensitivity levels have not yet been confirmed. Cannabis Clinic is calling for clarification to ensure clinics across Aotearoa can give patients accurate and up-to-date guidance on driving while using prescription medicinal cannabis.

Under the Land Transport Act 1998, medicinal cannabis patients in New Zealand have the right to a medical defence. However, having an up‑to‑date prescription or medication label does not automatically provide a defence at the roadside. If a patient receives an infringement notice, Cannabis Clinic will assist by helping them dispute the claim, providing formal letters, proof of prescription and clinical backing.

Cannabis Clinic Clinical Director, Dr William Parkyn, says "We've already heard concerns from our patients about what this testing means for them, and I'm sure Kiwis all over the country share these concerns. We're prepared to assist them wherever necessary to prove that they were using their medication as clinically advised, and support them to dispute claims as they have the right to do."

"At the end of the day, we believe it is unfair to punish law‑abiding, unimpaired patients using THC under prescription. The current approach is discriminatory against medicinal cannabis users and only adds further stigma to those using their medication responsibly."

Cannabis Clinic emphasises harm minimisation and a patient‑centric approach to healthcare. Its doctors and nurses provide patients with advice on driving and impairment based on current scientific evidence, helping ensure that use of prescription medicinal cannabis is both legal and safe. The clinic also has up‑to‑date resources available during consultations and on their website here.

"We want to open a dialogue with the Ministry and NZ Police to find an alternative testing path that creates safer roads while allowing patients to access the legal medication they have a right to," adds Dr Parkyn.

Cannabis Clinic encourages patients with questions about the new roadside drug testing law to contact the team at support@cannabisclinic.co.nz.