The Drug iatrogenesis corresponds to the pathology or any clinical manifestation undesirable for the patient induced by the administration of one or more medicines. Several studies have estimated that adverse drug reactions account for between 0.5% and 2% of outpatient consultations and are involved in 4% to 10% of hospital admissions Thus, we will present definitions essential to the understanding of drug-induced iatrogenesis before synthesizing the different epidemiological data available in this field. 

The evolution of modern medicine is closely linked to advances in drug therapy. But after these advances or the hopes of scientists have been filled, or the failures of the past have given way to the most unexpected successes, new problems have arisen. Accidents related to care and medication in particular have multiplied and have begun to worry healthcare professionals, and we hear about drug-induced iatrogenism, adverse effects or even adverse drug events. These are complex, alarming and yet media-like terms.

There is no more striking example than that of the immense tragedy of thalidomide used in the 60s as sedative and anti-nauseous, especially in pregnant women and caused serious congenital malformations. This is an extreme example but there are many drugs which, misused, are responsible for accidents ranging from simple digestive kto death. The causes intolerance explaining this are multiple communication errors between professionals or with the patient, poor product knowledge, misuse.