Driving with a medical prescription: what Swiss law saysDriving with a medical prescription: what Swiss law says

Can I drive if a physician has prescribed me a medicine containing THC? The short answer: the prescription changes how a THC finding is assessed, but it does not change the basic rule that nobody may drive while impaired.

The basic rule: fit to drive or not at all

Article 31 paragraph 2 of the Road Traffic Act (SVG) says that anyone who lacks the necessary physical and mental capacity because of alcohol, narcotics or medication is unfit to drive for that time and may not drive. This applies to everyone, with or without a prescription.

Zero tolerance, and the exception for prescriptions

For some substances Swiss law works with zero tolerance. Article 2 paragraph 2 of the Traffic Rules Ordinance (VRV) lists them, THC among them: if THC is detected in a driver's blood, unfitness to drive counts as proven. According to the ASTRA ordinance (VSKV-ASTRA, Art. 34), THC counts as detected from 1.5 micrograms per litre of blood.

Paragraph 2ter of the same article contains the exception. For people who can prove that they take one of these substances on a medical prescription, unfitness to drive is not already proven by the detection of the substance.

That is the decisive difference: without a prescription, the finding alone is enough. With a prescription, the police and the courts have to assess whether you were actually impaired.

What the exception does not do

The prescription is not a licence to drive. If you are impaired, you are unfit to drive, and the consequences are serious:

• Driving while unfit is a criminal offence and can be punished with a custodial sentence of up to three years or a monetary penalty (Art. 91 para. 2 SVG).
• It counts as a serious offence under the rules on driving licences, with a withdrawal of at least three months (Art. 16c SVG).

What this means in practice

• Carry proof of your prescription, for example the pharmacy label on the original packaging, so you can show it in a check.
• Do not drive if you feel any effect. Whether you feel fit is not the same as being fit.
• Talk to the physician about driving, in particular at the start of a treatment and after any change. Fitness to drive is a fixed part of the consultation in our practice.
• In safety-critical jobs, other rules may apply. Clarify them with your employer or the relevant authority.

In our practice

Our physician Oxana Smagulova discusses fitness to drive with every patient. The legal texts are linked on our page Legal framework and official sources.

This article is general information and not legal or medical advice.