Driving on medical cannabis in South Africa — the National Road Traffic Act and your prescription

The National Road Traffic Act 93 of 1996 prohibits driving while under the influence of intoxicating liquor or any drug having a narcotic effect, **whether prescribed or not**. The same standard applies to opioid analgesics, sedative anti-histamines, benzodiazepines, and cannabinoid medications. The fact that a doctor prescribed the medication does not provide a defence if the medication is impairing your driving.

Cannabis-specific roadside testing in South Africa has historically been less standardised than for alcohol, but enforcement frameworks are evolving. Patients should not assume that "they can't test for it" provides protection — both visible impairment (assessed by the officer) and laboratory testing of blood samples can underpin charges.

**THC-containing formulations** — THC at therapeutic doses can affect reaction time, attention, and complex motor coordination, particularly during dose-titration and for several hours after each dose. Effects diminish with steady-state dosing in chronic users but do not disappear. The half-life of THC is variable (4–24 hours depending on chronicity of use); the impairment window is shorter than the detection window.

**CBD-only formulations** — CBD is not associated with the same reaction-time and attention impairment as THC in controlled studies. CBD-leaning regimens are generally less restrictive for driving, but sedation effects do exist at higher doses and individual response varies.

**Balanced THC:CBD oils** — fall between the two extremes; treat them with the THC-side caution especially during dose-titration.

**Initial titration period (first 2–4 weeks)** — driving abstinence is the safer default during titration, regardless of formulation, while you establish how the regimen affects you.

Driving guidance is specific to your regimen and discussed during the consultation. Generally:

For THC-dominant regimens, abstain from driving during titration and for at least 4–6 hours after each dose once stable. Evening-only dosing minimises driving conflict for many patients.

For CBD-leaning regimens, lower restriction but observe yourself first. If you feel sedated, do not drive.

For oromucosal THC:CBD sprays studied in MS spasticity, the prescribing literature includes specific driving-restriction language that the doctor will share.

Document any new sedation or impairment after dose changes. If you operate heavy machinery or drive professionally (commercial truck, taxi, ride-share), the calculus changes — be explicit about your work in the consultation.

Carry your prescription documentation when transporting medication or when driving on prescribed medication. The documentation does not exempt you from impairment law but supports the legitimate-use context. Cooperate with any roadside assessment. Do not drive if you feel impaired, regardless of how recently you dosed — your subjective state at the wheel is what matters operationally and legally.