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

Background: methylphenidate (mph) has been used to induce emergence from general anesthesia. objectives: the objective of the present study was to evaluate the effect of mph on recovery from propofol and ketamine anesthesia in dogs. methods: 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. results: 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<0.05). respiratory rate after administration of methylphenidate was more stable than that of saline. conclusions: 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.