The law requires that healthcare professionals adequately inform patients about possible side effects when they prescribe new pharmacological treatments. There are several reasons (lack of time, fear of nocebo effect, patient and prescriber preferences) why informing patients in detail could be undesirable or even harmful. Prescribers should focus on two types of side effects: (a) common side effects with significant impact on the quality of life and (b) side effects that should be recognised in time to prevent further harm. During treatment, patients should be monitored regularly for efficacy and side effects in order to weigh benefits and risks and to stop or switch therapy when necessary.