Mr. D., aged 31, was found lying unconscious on his back on the grounds of his residence with bed sheets wrapped around his neck and attached to a tree branch for the purposes of suicide by hanging. Emergency services arrived at his residence where a Glasgow Coma Scale score of 6 led to tracheal intubation. The cardiovascular examination showed tachycardia. Blood tests performed on admission revealed hyperglycemia (3.80g/L), metabolic acidosis, alcohol concentration at 0.16g/L, CRP at 110mg/L and transaminases (AST) at 84IU/L. A bag of white powder and an empty vodka bottle were found at the patient's residence, suggesting simultaneous use of alcohol and cocaine. Therefore, a charge of illegal drug possession was filed by the police and a blood specimen was collected to test for alcohol, drugs of abuse and medications. The forensic tests on Mr. D.’s blood, performed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), revealed the presence midazolam (not quantified), methylone (936ng/mL), and mephedrone (116ng/mL). Other tests were negative, including cocaine. Concomitant consumption of alcohol and cathinone may induce coma, associated to hyperglycemia. This case, with detection of illegal drugs by an expert laboratory using standard techniques is shown here to be critical to understanding the clinical effects of suspected drugs; this type of analysis must be prescribed rapidly once the patient is hospitalized (short half-lives and stability problems of mephedrone).