Driving on medication in Belgium: when is it an offence?

For drugs, zero tolerance applies in traffic. Not for medication: someone who takes a prescribed sleeping pill and then gets behind the wheel is not automatically committing an offence. Medication can nevertheless lead to prosecution, and in some cases even to the loss of your licence. It all depends on the medicine, your condition and what you knew.

This article is part of our guide to drug driving in Belgium.

No zero tolerance, but other rules

Article 37bis of the Road Traffic Act (loi relative à la police de la circulation routière) only punishes the presence of certain substances: THC, amphetamine, MDMA, opiates such as morphine, and cocaine. Ordinary medicines are not on that list. For medication, there are three other routes by which you can still commit an offence.

1. A state similar to drunkenness

Article 35 of the Road Traffic Act punishes driving while drunk “or in a similar state”, in particular as a result of drugs or medication. Someone who loses control of his or her actions because of medication, for example through drowsiness, confusion or severely slowed reactions, can therefore be prosecuted. As with drunkenness, it depends on what the police observe. See our article on drunkenness or alcohol intoxication.

2. Not being in a fit state to drive

Article 8.3 of the Highway Code (Code de la route) provides that every driver:

must be in a fit state to drive;
must have the required physical qualities;
must have the necessary knowledge and skill;
must at all times be able to carry out all the manoeuvres required of him or her;
must at all times be in control of his or her vehicle.

Someone who weaves across the road because of medication breaches this provision, even if there is no question of a state similar to drunkenness.

3. Driving when you are not medically fit to drive

The strictest regime concerns medical fitness to drive. Anyone who applies for a driving licence declares that he or she does not suffer from any of the conditions determined by the King (Article 23 of the Road Traffic Act). Those conditions and the medical standards are set out in Annex 6 of the Royal Decree of 23 March 1998 on the driving licence.

That annex also contains standards on alcohol, psychotropic substances and medication. Someone who is dependent on psychotropic substances or uses them excessively is not fit to drive. The same applies to someone who regularly uses substances or medicines in quantities that adversely affect driving.

The three categories of medicines

Annex 6 classifies medicines according to their effect on fitness to drive:

Category	Effect	Advice
1	Probably no negative effect	Where possible, the doctor chooses a medicine in this category
2	Slight or moderate effect	Do not drive during the first days of treatment, or until you know the effects
3	Serious effect	The doctor advises against driving

The doctor must inform you of the possible consequences of a medicine for your driving, including in combination with other medicines or with alcohol. If the doctor finds that you no longer meet the medical standards, he or she must tell you that you have to hand in your driving licence. From that point, the responsibility lies with you.

Handing in your driving licence

Article 24 of the Road Traffic Act obliges a licence holder to hand in the licence when he or she suffers from one of the conditions in Annex 6. This must be done within four days of becoming aware of it, not counting Saturdays, Sundays and public holidays. You get the licence back if, in the cases determined by the King, you pass a medical exam.

Someone who, after dependence on alcohol or psychotropic substances, can prove demonstrated abstinence of at least six months can be declared fit to drive again. That fitness is then valid for a maximum of three years.

What do you risk?

Anyone who drives a motor vehicle while suffering from a condition in Annex 6, or without having undergone a medical exam that was imposed, commits an offence (Article 30, § 1, 4° of the Road Traffic Act). According to the Court of Cassation, the condition does not have to have been established by a doctor at the time of the offence. It can also be shown afterwards (Cass. 26 April 2016, P.15.1565.N).

The judge can also declare you unfit to drive under Article 42, if he or she finds that you are not physically or mentally fit to drive. That driving ban (déchéance du droit de conduire) lasts until you prove otherwise. See our article on unfitness to drive under Article 42.

Medicines containing a prohibited substance

Some medicines contain a substance that is on the Article 37bis list, such as morphine or the THC in medical cannabis. A saliva test or blood analysis can then be positive, even if you are using the medicine as prescribed. Discuss this with your doctor in advance and keep your prescription and the package leaflet to hand. If you are prosecuted, a well-documented explanation to the judge is essential.

Practical tips

Read the package leaflet and ask your doctor or pharmacist how the medicine affects driving.
Do not drive during the first days of a new treatment or after an increase in the dose.
Never combine medicines that are dangerous for driving with alcohol.
If you are stopped, mention which medicines you are taking and on what prescription.

Frequently asked questions

Can I drive on sleeping pills or sedatives?

That depends on the medicine, the dose and when you took it. Many sleeping pills and sedatives fall into the category with a moderate or serious effect on fitness to drive. Do not drive during the first days of a new treatment and ask your doctor or pharmacist for advice. Anyone who loses control of the vehicle because of such medicines risks prosecution.

Do I have to hand in my driving licence if I take certain medicines?

Only if you suffer from a condition in Annex 6 of the Royal Decree on the driving licence, for example dependence or regular use that adversely affects driving. You must then hand in the licence within four working days. Your doctor must inform you of this. For normal, correct use of medication, this obligation does not apply.

Is medical cannabis allowed when driving?

THC is on the list of substances prohibited in traffic, even if it comes from a medicine. A saliva test or blood analysis can therefore be positive when it is used on prescription. Discuss this with your doctor in advance, keep your prescription and do not drive if you feel the effect of the medicine. If you are prosecuted, a well-documented file is essential.

Can I be prosecuted if I did not know my medicine affects driving?

Your doctor must inform you of how a medicine affects driving. The judge does, however, expect you to read the package leaflet. In a prosecution for driving in a state similar to drunkenness, the judge can take the circumstances into account, for example an unexpected reaction to a new medicine. That mainly affects the choice of penalty.

What is a “similar state” to drunkenness caused by medication?

It is a state in which you lose control of your actions because of medication, comparable to drunkenness: drowsiness, confusion, an unsteady gait or severely slowed reactions. The police establish it on the basis of outward signs, as with drunkenness. The penalties are the same, including a compulsory driving ban of at least one month.

Have your case reviewed

Have you been summoned (citation) to the police court (tribunal de police) after a check in which medication played a role? We examine your file and the medical documents. Contact us.

Law as at 28 September 2026. We update this article when the rules change.

Driving under the influence of medication: what is a criminal offence?