Abusive use of drugs is a public health problem worldwide. The use of these substances by pregnant or lactating women can have many serious side effects in newborns. Among the commonest causes of addiction in drug users is cocaine in powdered form, inhaled, intravenously injected or smoked form (crack). Fast screening and a confirmation test using high specificity and sensitivity instruments such as LC–MS or GC/MS, can provide data to qualify and quantify chemical substances present in biological samples such as breast milk or meconium. Cocaine and/or crack can be detected through biomarkers or the unchanged molecule, enabling the form of cocaine use to be distinguished through the analytes. These methods must be carefully developed and validated according to internationally recognized guidelines. Thus, the study of biological matrices in which it can be detected through the development of simple and quick analytical methods can help prevent intoxication and diagnose the symptoms of dependency such as seizures, especially in babies, providing appropriate medical care.