Case 3: Fever, Vomiting, and Increased Sleepiness in a 4-year-old Girl

1. B. Jason Brotherton, MD* 2. Irving Steinberg, PharmD* 3. Jeffrey L. Johnson, MD* 1. *LAC + USC Medical Center, Los Angeles, CA. A 4-year-old girl presents with 1 week of fever, vomiting, and increased sleepiness. Her medical history includes cerebral palsy, intellectual disability, and epilepsy treated with carbamazepine (CBZ) for the past 2 years. The last change in CBZ dosing was 2 months ago after a seizure. The girl’s mother reports that she repeated several doses of CBZ after emesis for the past 2 days. Of note, the family travelled to Mexico 3 weeks ago. On physical examination, the girl’s temperature is 102°F (38.8°C); other vital signs are normal for age. She appears fatigued but is easily aroused. When not stimulated during the physical examination, she quickly goes back to sleep. Results of her neurologic evaluation are unchanged from her baseline hypertonia and hyperreflexia. She has scleral icterus. Her abdomen is soft and nontender, with a palpable liver edge 3 cm below the right costal margin. Initial laboratory findings document thrombocytopenia (77×103/μL [77×109/L]), aspartate aminotransferase (AST) 4231 U/L (70.66 μkat/L), alanine aminotransferase (ALT) 2660 U/L (44.42 μkat/L), alkaline phosphatase 375 U/L (6.26 μkat/L), total bilirubin 7.3 mg/dL (124.86 μmol/L), conjugated bilirubin 5.8 mg/dL (99.2 μmol/L), prothrombin time (PT) 23.7 seconds, and international normalized ratio 2.09. Serum CBZ concentration is 25.5 mg/L (therapeutic range, 4–12 mg/L). White blood cell count is 6900/μL (6.9×109/L), with 57% neutrophils, 34.8% lymphocytes, 7.7% monocytes, 0.3% eosinophils, and 0.2% basophils. …