In this Clinical Lesson, using two illustrating cases, we explain how to do the initial assessment and treatment of an intoxicated patient. An approach aimed at toxidromes can serve as a stepping stone. A toxidrome is a combination of symptoms and clinical features that can occur with the use of certain drugs and substances. The most commonly encountered toxidromes are sympathomimetic, serotonergic, anticholinergic, cholinergic, sedative-hypnotic and opioid. All patients need to be approach according to the ABCDE method. The treatment is based on pharmacokinetics by means of the ADME principle (absorption, distribution, metabolism and excretion) and based on pharmacodynamics, aimed at the toxidrome.