Abstract
A 22-year-old woman attempted suicide by overdosing on prescription drugs (lithium carbonate, sodium valproate (VPA), etc.). Her condition was stable on admission except for consciousness, but decreased blood pressure and polyuria were observed thereafter. Polyuria was attributed to diabetes insipidus caused by the lithium carbonate. Since blood levels of VPA were high (190.2μg/dl), continuous hemodiafiltration (CHDF) was initiated. In addition, levocarnitine chloride solution and lactulose were used concurrently. CHDF was discontinued after one session and the patient was discharged on day 6. Lithium overdose can cause fatal arrhythmia. This patient overdosed on lithium carbonate in addition to long-term use. Moreover, VPA overdose can cause problems including brain edema and death. This patient had a high blood VPA level. Lithium has a low protein binding rate, as does VPA when overdosed. CHDF was therefore performed and satisfactory recovery was made. The VPA taken by this patient was a sustained release preparation and the likely course of changes in internal absorption, blood levels, and protein binding rate were difficult to predict. Ultimately, we determined the treatment plan through measurement of blood levels of VPA. When managing cases of complex drug intoxication, sequential and rapid toxicology/drug analysis and a system for measuring blood levels are considered essential.
