3.1 Characteristics of the identified studies
The search criteria on PubMed, Web of Knowledge and Cochrane databases
yielded 932 hits of which 324 were duplicates. After removal of
additional 590 records (including one [21] of the two articles
[21, 22] with the same sample published in different journals was
excluded), 13 studies of CBZ resistance [7, 8, 13, 14, 22-30] and 8
studies of CBZ metabolism [7, 8, 17, 25, 29, 31-33] were included in
the systematic review (Fig. 1). All participants in the studies were
epilepsy patients and were treated with CBZ monotherapy at a stable
maintenance dose. The characteristics of included studies are presented
in Table 1 and 2. All the patients were treated with CBZ in a dose range
of 400–1200 mg/day. The NOS scores of the included studies ranged from
5 to 8 based on the NOS evaluation system, indicating a relatively high
quality of included studies. Furthermore, a test of funnel plot was not
conducted due to the insufficient number of studies in the present
study.