Effect of dexamethasone on emesis after morphine administration in animal model

 Background & Objective: Morphine is commonly used to relieve moderate to severe pain, but some side effects include vomiting. The Objective of this study was to evaluate the anti-emetic properties of dexamethasone in animal models receiving morphine. Materials & Methods: In a clinical study fourteen cross breed dogs that were 2 and 4 years old were assigned to two equals groups. The Treatment group received dexamethasone (1 mg/kg intra muscularly), 60 minutes prior to morphine administration. The Control group received 2 cc of saline intra muscularly (IM), 60 minutes prior to morphine administration. After 60 minutes all dogs received morphine (1 mg/kg intra muscularly). After morphine was administrated all dogs were observed for 1 hour to allow assessment of frequency of emesis and time until the onset of the first emetic episode and then they were compared accordingly.Results: The Mean ± SD for the first emetic episode in the treatment group was 266 ± 49. The same number was  197.6 ± 31.84 in the control group. There was no statistically significant deference for the time of the first emetic episode between treatment and control group (P = 0.23). There was no statistically significant deference for the number of emetic episodes between the treatment and control group (P = 0.16). There was no statistically significant deference for the weight of the dogs between the treatment and control groups (P = 0.95).Conclusion: in the current study, the administration of dexamethasone 1 hour before administrating morphine was not able to significantly affect the frequency of emetic episodes or the time period before the occurrence of the first emetic episode.