Effects of dexmedetomidine and midazolam on motor coordination and analgesia: a comparative analysis

We compared the effects of 2 sedative drugs, dexmedetomidine and midazolam, on motor performance and analgesic efficacy in a rat model.

Rats were randomly divided into the following 4 groups on the basis of the treatment received. The first group received 83 µg/kg/min midazolam; the second, 1 µg/kg/min dexmedetomidine; the third, 83 µg/kg/min morphine; and the fourth was a control group. The rats were measured motor coordination and pain reflexes by using rotarod, accelerod, hot plate, and tail flick tests.

At all the tested speeds, the midazolam-injected rats remained on the rotarod longer than did the dexmedetomidine-injected rats. Furthermore, in the 10-minute accelerod test, the midazolam-injected rats remained for a longer duration than did the dexmedetomidine-injected rats. The latency time for the hot plate test was significantly higher at 10 minutes and 20 minutes in the dexmedetomidine group than in the midazolam group. Further, the latency time at 10 minutes for the tail flick test was greater in the dexmedetomidine group than in the midazolam group.

In this rat model, midazolam results in faster recovery of motor coordination performance when compared with dexmedetomidine.