Aim: To investigate antiepileptic drug (AED)-related weight changes in patients with epilepsy through a retrospective observational study.
Method: We analysed the anonymised electronic primary care records of 1.1 million adult patients in Wales. We included patients aged 18 years and over with a diagnosis of epilepsy, whose body weight had been measured up to 12 months before starting, and between 3 and 12 months after starting, one of five AEDs. We calculated the weight difference after starting the AED for each patient.
Results: 1423 patients were identified in total. The mean difference between body weight after and before starting each AED (together with 95% CI and p values for no difference) were: carbamazepine (CBZ) 0.43 (-0.19 to 1.05) p=0.17; lamotrigine (LTG) 0.31 (-0.38 to 1.00) p=0.38; levetiracetam (LEV) 1.00 (0.16 to 1.84) p=0.02; sodium valproate (VPA) 0.74 (0.10 to 1.38) p=0.02; topiramate (TPM) -2.30 (-4.27 to -0.33) p=0.02.
Conclusions: LEV and VPA were associated with significant weight gain, TPM was associated with significant weight loss, and LTG and CBZ were not associated with significant weight change.
Keywords: Anticonvulsants; Epilepsy.