title: Appropriateness of anticonvulsant concentration monitoring in hospitalized pediatric patients.
abstract: OBJECTIVE
  We assessed the appropriateness of anticonvulsant concentration monitoring in hospitalized pediatric patients admitted to a teaching hospital.
  
  
  METHODS
  Literature-based criteria for anticonvulsant concentration monitoring were approved by the Pharmacokinetic and Neurology Services of Le Bonheur Children's Medical Center. A random sample of anticonvulsant concentrations ordered over a 6 month period was assessed. Patient demographics, anticonvulsant data, the type of professional who recommended the concentration, and sampling time were collected concurrent with hospitalization. Concentrations were assessed for appropriateness of indication and sampling time.
  
  
  RESULTS
  Concentrations (n=141) were obtained in 74 patients (mean age = 6.5+5.5 years) admitted to the floor (86%) or ICU (14%). Length of stay was 8.3+16.9 days. Monotherapy was used in 78.3% of patients. Carbamazepine (28.4%), phenytoin (27.5%), phenobarbital (27.6%), valproate (14.8%) or free phenytoin (1.7%) concentrations were recommended by a pediatrician (70.5%), neurologist (21.5%), neurosurgeon (2.1%), or Pharmacokinetic Services (5.9%). Fifty-three percent of all concentrations met appropriateness criteria for indication; however, 8.5% of tests were collected incorrectly. About half of the concentrations recommended by pediatricians (47.5%), neurologists (43.3%), and neurosurgeons (66.7%) did not meet appropriateness criteria for indication. The main reasons for inappropriate anticonvulsant concentration monitoring include frequent repetitive sampling (<24 hours), obtaining an anticonvulsant concentration without an appropriate indication, failure to correctly apply the concept of pharmacological steady-state, incorrect identification of drug-drug interactions, and sampling irrespective of dosing schedule.
  
  
  CONCLUSIONS
  One-half of all anticonvulsant concentrations fulfilled the indication criteria. There was no difference in appropriateness of indication based on the service recommending the concentration or for each specific anticonvulsant. The appropriateness rates reported are comparable to those reported in other studies. Inappropriate anticonvulsant concentration monitoring fails to improve patient care and contributes to a significant waste of financial resources.
authors.affiliation: Departments of Neurology and Pharmacy, Cleveland Clinic Foundation, Cleveland, Ohio.
authors.forename: Collin A
authors.initials: CA
authors.lastname: Hovinga
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Rose
authors.forename: Stephanie J
authors.initials: SJ
authors.lastname: Phelps
keywords: anticonvulsants; antiepileptics; pediatrics; therapeutic drug monitoring