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

The objective of this study was to compare the effects of two drugs on motor performance and analgesic efficacy in a rat model.

Rats were randomly divided into four groups as follows: propofol (600 μg/kg/min), dexmedetomidine (1 μg/kg/min), morphine (83 μg/kg/min) and control. The rats were placed on a rotating rod and tested at the slowest speed (5 rpm) and then at increasing increments from 5, 10, 15, 20, 25, 30, 35 to 40 rpm. The speed was set up again from 1 to 79 rpm within 4 and 10 min for the accelerod test, respectively. Pain reflexes in response to a thermal stimulus were measured at 0, 10, 20 and 60 min after the drug injection using the hot-plate test.

Dexmedetomidine injected rats showed an increased length of time compared to the propofol group at 20 rpm, 25 rpm, 35 rpm and 40 rpm speeds during the rotarod test. The latency times for the hot-plate test increased significantly for the propofol, at 0, 10 and 20 min compared to the control. At 10 min the latency times of the propofol group were longer than the dexmedetomidine group.

For long-term analgesic benefit propofol treatment seems to be better than the dexmedetomidine group. Dexmedetomidine may be preferable in day-case surgery and sedation applications in intensive care units as it provided a faster onset of recovery of motor coordination performance.