Prolonged Elimination of Lamotrigine After Suicidal Overdose: A Case Report.

A 22-year-old female with bipolar disorder intentionally ingested a large amount of medication, including 4,100 mg of lamotrigine (LTG), an antiepileptic drug, as well as other substances such as antipsychotics, acetaminophen, and alcohol. When she arrived at the hospital, approximately one hour after ingestion, she was confused and had mild liver enzyme elevation but no significant heart rhythm abnormalities. The initial treatment included administering activated charcoal, N-acetylcysteine therapy, and intravenous fluids to manage the overdose. Despite these interventions, the patient's condition worsened, and she became comatose by the second day in the hospital. She also developed a mild skin rash, later diagnosed as urticaria. However, the patient's condition improved, with her liver function and consciousness gradually returning to normal. By the sixth day in the hospital, her liver enzymes had normalized, and she had made a full neurological recovery. The patient was discharged on the seventh day without any residual deficits. The serum measurements of LTG revealed a non-linear elimination pattern, with an estimated half-life of approximately 100 hours between the first two measurements. This was unusual, given the patient's young age, normal body mass index (BMI), and lack of liver disease. The researchers hypothesized that the delayed clearance of LTG may have been due to the saturation of the hepatic metabolic pathways, which was resolved once the liver enzymes returned to normal. This case highlights the importance of closely monitoring patients who have overdosed on medications, as prolonged disturbances in consciousness may indicate extended drug half-lives due to metabolic dysfunction. Further evaluation is necessary to identify and address potential causes of delayed elimination, and this case serves as a reminder to consider non-linear pharmacokinetic behavior in cases of drug overdose.

Link: https://pubmed.ncbi.nlm.nih.gov/40078254/