The most comprehensive and official resource for drug interactions at the "Contraindicated" (contre-indiqué) level in France is the , published by the Agence Nationale de Sécurité du Médicament (ANSM) .
The ANSM classifies interactions into four increasing grades of importance:
: This is the primary reference guide used by healthcare professionals to identify absolute contraindications (CI), associations to be avoided (ASDEC), and precautions for use.
: An online portal that allows you to download the most recent PDF updates and search for specific drug pairs. Understanding the 4 Severity Levels
: The association is possible provided that specific recommendations (e.g., monitoring, dosage adjustment) are followed.
: Should be avoided unless a strict benefit/risk assessment justifies it.
The "Contraindicated" level is the highest of the four official clinical severity grades and has an absolute character; it must not be transgressed due to frequent and severe clinical consequences. Essential Official Documents
: Absolute prohibition. The association must not be prescribed.