Antiepileptic drug utilization in children from 1997-2005--a study from the Netherlands.
OBJECTIVE
To investigate the utilization of antiepileptic drugs (AEDs) in Dutch children and compare this with guidelines on the treatment of epilepsy in children.


METHODS
From the Dutch Interaction Database (IADB.nl) we selected children aged 0-19 years who received at least one prescription for an AED (ATC-code beginning with N03A) between 1997 and 2005. We calculated cumulative incidences and prevalences per 1000 children per year, stratified by age-category, sex and type of AED, and the total number of months each patient received at least one prescription of AEDs, and we counted the number of person-months and AEDs prescribed. For each AED, proportions of person-months were calculated for mono- and combination therapy. Kaplan-Meier survival analysis was used to analyse the duration of AED use, stratified by sex.


RESULTS
The overall prevalence of the prescription of AEDs to children was constant at approximately 4.0 per 1000 children during the years of the study. The overall cumulative incidence from 1997-2005 was 0.67 per 1000 children. When stratified by age category or sex, there were no relevant differences in incidence or prevalence. Valproic acid was the most frequently prescribed drug, followed by carbamazepine and lamotrigine. In 20.3% of all person-months, patients received combination therapy; of these, 34.2% received combination therapy for 3 person-months or less. The older AEDs were prescribed more often as monotherapy than combination therapy, in contrast with the newer AEDs, for which the opposite was true. The 50% survival probability (= time period when 50% of children had stopped using AEDs) was around 2 years, with a significantly lower discontinuation of treatment for girls than boys (P = 0.04).


CONCLUSIONS
The overall cumulative incidence of AEDs was determined to be 0.67 per 1000 children, and the prevalence 4.0 per 1000 children. The most frequently prescribed drug is valproic acid, followed by carbamazepine and lamotrigine. The prescribing of AEDs seems to be in conformity with the overall recommendations of the guidelines on the treatment of epilepsy in children.
van de Vrie-Hoekstra
N W
NW
Department of Social Pharmacy, Pharmacoepidemiology and Pharmacotherapy, Groningen University Institute of Drug Exploration, Groningen, The Netherlands.
de Vries
T W
TW
van den Berg
P B
PB
Brouwer
O F
OF
de Jong-van den Berg
L T W
LT
D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D002220:Carbamazepine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D002648:Child; D016208:Databases, Factual; D004363:Drug Utilization; D004827:Epilepsy / Q000188:drug therapy* / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D000077213:Lamotrigine; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D017410:Practice Guidelines as Topic; D015995:Prevalence; D012189:Retrospective Studies; D014227:Triazines / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D014635:Valproic Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use
D000927:Anticonvulsants; D014227:Triazines; D002220:Carbamazepine; D014635:Valproic Acid; D000077213:Lamotrigine