Effect of dexamethasone on emesis after morphine administration in animal model

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. 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. 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). 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.