Open AccessAcute Phenytoin Intoxication: Causes, Symptoms, Misdiagnoses, and Outcomes
Author(s) -
Hwang WenJuh,
Tsai JingJane
Publication year - 2004
Publication title -
the kaohsiung journal of medical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.439
H-Index - 36
eISSN - 2410-8650
pISSN - 1607-551X
DOI - 10.1016/s1607-551x(09)70262-1
Subject(s) - medicine , phenytoin , anesthesia , emergency department , vomiting , nausea , epilepsy , pediatrics , psychiatry
Phenytoin is a commonly prescribed antiepileptic drug. Due to its saturation (zero‐order) pharmacokinetics, phenytoin carries a special risk of dose‐related toxicity that is an important issue in emergency medicine. The purpose of this cross‐sectional case‐series study was to investigate the causes, symptoms, misdiagnoses, and outcomes of acute phenytoin intoxication. It was based on a retrospective chart review of 30 inpatients (mean age, 41.6 ± 22.8 years) with 36 episodes of acute phenytoin intoxication at our university hospital in the past 13 years. The average initial serum phenytoin level was 47.3 ± 9.7 μg/mL (range, 27.9‐70.4 μg/mL). Excessive self‐medication, misunderstanding of the prescription order, and probable drug interaction were the three leading causes of acute phenytoin intoxication. Unsteady gait, dizziness/vertigo, nausea/vomiting, general weakness, and drowsiness were the most common presenting symptoms. The tentative diagnostic accuracy was 67%. The most common initial misdiagnosis was brainstem or cerebellum stroke (14%). The clinical course in all patients was uneventful under temporary withdrawal of phenytoin and supportive care. We concluded that acute phenytoin intoxication was relatively under‐diagnosed in the emergency service. Although acute phenytoin intoxication causes no mortality and has a good outcome, the unsteady gait increases the risk of injuries caused by falls. The management of acute phenytoin intoxication includes temporary withdrawal of phenytoin and supportive care.