Table 1 Characteristics of study population
Demographic factors | N | Median (range) |
 Male | 114 (59.5 %) |  |
 Female | 81 (41.5 %) |  |
 Age |  | 67.0 (20–90) |
Dose of pregabalin | Â | Median (range) |
 Initial dose, mg/day |  | 75 (25–450) |
 Maintenance dose, mg/day |  | 150 (25–450) |
Adverse effects | N | |
 Patients who developed one or both of side effects | 63 (32.3 %) | |
 Patients who developed somnolence | 47 (24.1 %) | |
 Patients who developed dizziness | 34 (17.4 %) | |