Acute zolpidem poisoning--analysis of 344 cases

Zolpidem is a new short acting hypnotic agent, first launched in France in 1988. Three hundred forty-four cases of intentional acute overdoses are reviewed retrospectively. Patients were predominantly female (70%) in their third or fourth decade. Ingested doses of zolpidem ranged between 10 and 1400 mg (one pack or less in 80%). Half of the patients ingested other substances (psychotropic drugs and alcohol) concomitantly. Signs of intoxication were observed in two thirds of the population but could be attributed to zolpidem in only 105 cases: drowsiness (N = 89) occurred at doses of 140 to 440 mg; coma (N = 4) or respiratory failure (N = 1). Other symptoms were rare (excepted vomiting, N = 7). Of the rare electrocardiographic or biological abnormalities, none appeared to be directly related to zolpidem. Therapy for intoxication was usually limited to supportive measures and/or gastric lavage. Symptoms of intoxication rapidly remitted in 91% of cases. Three percent of patients with multiple drug ingestion recovered despite severe complications during intensive care. Fatalities were reported for 6% but could not be directly linked to zolpidem. Previous published reports are confirmed: zolpidem acute overdose is generally benign and requires no specific therapeutic measures.