Clinical Characteristics of Acute Zolpidem Intoxication

ABSTRACT

PURPOSE: The hypnotic effect of zolpidem is comparable to benzodiazepines, but has less abuse and addiction potential than benzodiazepines, so is one of the most commonly prescribed hypnotics. The frequency of acute zolpidem overdose has increased, but clinical analysis and severity predictors are not known in Korea. METHODS: A retrospective evaluation of histories, clinical courses, and laboratory findings of each patient treated from June, 2000, to May, 2006, in a university hospital for acute zolpidem intoxication. RESULTS: We evaluated 30 patients, including 16 co-intoxication cases. Twenty-five patients presented mental alterations but became alert within 2 days. All patients recovered completely. The median zolpidem concentration was 0.9 mg/L (range 0.2~7.4 mg/L). There was a weak correlation between the amount ingested and zolpidem concentration (r=0.25). None of them presented severe laboratory abnormalities, and these abnormalities did not relate to zolpidem concentration. CONCLUSION: The clinical progress of acute zolpidem intoxication is mild. We could not predict zolpidem concentration or clinical severity from the amount ingested and could not predict the clinical course from laboratory findings in the emergency department.