In 100 in-patient cases, there were 23 patients (23%) with un-logical indication for gabapentin, with total amount of 213 viên (accounting for 14.7% of total amount of gabapentin), total cost of 2, 207, 700 VN dong (accounting for 15.2% of total cost of gabapentin), and the mean of un-logical prescriptions was lower than the logical ones (p = 0.032).