Drug allergies (DA) are mainly observed by general practitioners. The immediate management of reactions as well as further investigations include to know what are placebo negative reactions, linked to autonomic system hyper-reactivity. The chronology of drug intakes and related symptoms has to be specified. In case of reactions, any drug must be stopped. Subsequent worsening of symptoms requires hospitalization. Biology is not useful, the dosage of tryptase excepted in the case of anaphylactoid shock. Allergological investigations should be conducted in the next three months. Safe guiding principles for future treatments are detailed.