Switch from originator to equivalent drug in the era of generic antiepileptic drugs: study of keppra versus epitiram clinical equivalence

OBJECTIVES: Generic antiepileptic drugs represent a measure to maximize cost saving. Levetiracetam (LEV) is one of most commonly used and effective antiepileptic drugs. The objective of our work was to demonstrate the effectiveness and safety of overnight switch from monotherapy with Keppra (original drug) to epitiram (generic drug) at the same dose. METHODS: In our observational study, we consecutively enrolled 37 seizure-free patients with epilepsy who expressed the wish to switch to a generic drug for economic reasons. During the 6-month evaluation period, we assessed treatment efficacy, tolerability, compliance, and intersubject variability of LEV serum concentration. At each visit, clinical and neurological examination, scales, video-electroencephalogram, and blood sample analysis to evaluate LEV plasma level were performed. RESULTS: A total of 36 of 37 enrolled patients switched from Keppra to epitiram, which was administered at the same dose in monotherapy. Three of 36 patients dropped out during follow-up for adverse events. The other 33 subjects had neither seizures nor adverse events. No significant differences in electroencephalogram features and scale scores were revealed; the intersubject variability of LEV serum concentration did not differ significantly at follow-up evaluation (P = 0.53). All the patients expressed good clinical personal impression and continued to take epitiram. The switchback rate was 8 %. CONCLUSIONS: The switch from Keppra to epitiram was easy and safe in our population, and epitiram can be considered as effective and tolerable as Keppra. Only a slight, non-statistically significant variability in LEV serum concentration was documented after the switch from Keppra to epitiram. Larger epileptic populations should be studied to confirm these results.