Acute carbamazepine (CBZ) poisoning is a common medical emergency, with severity assessed through clinical and laboratory findings. Its primary manifestations include neurological, cardiovascular, and anticholinergic effects, such as dry mouth, blurred vision, urinary retention, constipation, confusion, agitation, and seizures. Elevated serum CBZ levels are associated with the severity of neurological symptoms. This study evaluated the relationship between clinical findings and serum CBZ levels in acute poisoning cases.

A retrospective study was conducted at the emergency department of Mahmoud Yaacoub Center for Emergency Medical Assistance (2020–2023) on patients over 18 with at least one CBZ level measurement. Anamnestic and clinical data were collected from medical records to examine the relationship between serum CBZ levels and clinical findings.

Sixty-seven patients were included, with a median age of 29 years and a notable female predominance. Clinical findings revealed severe neurological symptoms in 15% including seizure in 1.5% and GCS≤12 in 13.4% of whom 10.4% were comatose. The median serum CBZ concentration was 19.50mg/L (13–29). Cutoffs serum carbamazepine levels predictive of severe neurological symptoms were identified as: 27.5mg/L for seizures (AUC 0.727, Sensitivity 100%, Specificity 72%; P=0.038), 28.5mg/L for GCS≤12 (AUC 0.952, Sensitivity 100%, Specificity 80%; P<0.001), and 29.5mg/L for coma (AUC 0.952, P<0.001, Sensitivity 100%; specificity 86%).

In our study, cases of acute CBZ poisoning, serum CBZ cutoffs were predictive of GCS≤12 and seizure, highlighting the importance of measuring serum CBZ for assessment of severity.