Abstract: Aim To observe the timed analgesic efets by butabital (B), acetaminophen (A) and affeine (C) in combination (BAC), in which the proportion was fixed as 1.25:8.1:1.Method Three types of experimental methods, including the tail flicking method, the hot plate method and the pessring tail method, were taken to detemine indices at diferent times after the animals were administered (ig) high, median and low BAC dose.Results and Conclusion BAC had a strong analgesic effect in three types of experiments. The effect began 30 min after administation, arived maximum at 1 bh, decreased al 2h and disppeared at 4h. There was a dose efet relationship between large and lite BAC dose.

Key words: acetaminophen, butabital, caffeine, combination drug therapy, analgesic effect