The use of methylphenidate for emergence from propofol and ketamine anesthesia in dogs

Methylphenidate (MPH) has been used to induce emergence from general anesthesia.
The objective of the present study was to evaluate the effect of MPH on recovery from propofol and ketamine anesthesia in dogs.
Six healthy male mix-breed dogs weighing 21.9 ± 3.9 kg were used in a randomized crossover design. Thirty minutes after premedication with acepromazine (0.1 mg/kg; IM), anesthesia was induced with either IV propofol or ketamine (8 and 15 mg/kg, respectively). Dogs, six minutes after induction, received either IV normal saline or methylphenidate (1 mg/kg) (propofol-saline; propofol-methylphenidate; ketamine-saline; ketamine-methylphenidate). Each dog was anesthetized four times randomly with at least one week interval.
No significant differences were observed between propofol-saline and propofol-methylphenidate as well as between ketamine-saline and ketamine-methylphenidate in the times needed for various chronological sequences of recovery (p>0.05). Recovery in the dogs that received methylphenidate was eventful and associated with some adverse effects. Heart rate showed a decrease in propofol-methylphenidate group compared to the base (p It was concluded that methylphenidate at 1 mg/kg could not shorten recovery time in the dogs premedicated with acepromazine and anesthetized with either propofol or ketamine. Testing lower doses of methylphenidate and using a different premedication agent are recommended for future studies.