Changing trends in antiepileptic drug prescribing in girls of child-bearing potential.

OBJECTIVE

To characterize trends in prescribing carbamazepine (CBZ), sodium valproate (VPA) and lamotrigine (LTG) in adolescent females in the UK and to examine possible reasons for changing trends.

DESIGN

Population-based observational study.

SETTING

UK General Practice Research Database between 1 January 1993 and 31 December 2006.

PATIENTS

12-18-year-old subjects who were issued >or=1 CBZ, VPA or LTG prescription.

MAIN OUTCOME MEASURES

Prescribing prevalences stratified by age, gender and antiepileptic drug.

RESULTS

5417 patients (47.6% females) were prescribed 147 111 prescriptions for CBZ (34.5%), VPA (38.6%) or LTG (26.9%). The prevalence of LTG prescribing in females increased from 0.08 (95% CI 0.04 to 0.12) to 0.80 (95% CI 0.70 to 0.89) per 1000 female population. Conversely, the prevalence in females of CBZ and VPA prescribing significantly decreased from 1.00 (95% CI 0.85 to 1.15) to 0.51 (95% CI 0.44 to 0.58) and from 0.94 (95% CI 0.80 to 1.09) to 0.63 (95% CI 0.55 to 0.72), respectively. This 10-fold rise in LTG prescribing in females is much higher than the fivefold rise in males from 0.09 (95% CI 0.05 to 0.14) to 0.47 (95% CI 0.40 to 0.54) per 1000 male population.

CONCLUSION

The practice of prescribing antiepileptic drugs in adolescents has changed gradually over the last decade. More females aged 12-18 years are prescribed LTG than CBZ or VPA and the increase is much greater than for males. The increase in LTG prescribing mirrors a corresponding decrease in both VPA and CBZ. Concerns about potential problems to offspring appear to be affecting prescription trends in adolescent females of child-bearing potential.