Tonsillectomy is not comparable with most other surgical interventions because the wound created by the excision of the tonsils is neither sutured nor covered by sealing or hemostatic material. It remains a large wound surface that is covered by crusting and exposed to food, inhaled air, and saliva (
14). In the tonsillectomy procedure, muscle and surrounding tissue damage may occur; this leads to activation of an acute inflammatory response in the surrounding tissues and consequently causes spasm of pharyngeal muscles, irritation of nerve endings, and in some cases, disruption of the mucosa (
15). Finally, the tissue damage results in an imbalance in the mechanisms of swallowing, incoordination, dysphagia, and pain. A review of the above events has shown that if the tissue damage could be prevented, the normal physiological mechanisms could be reestablished (
16). In previous studies, dexamethasone administrated has been administered for the children underwent a variety of surgical procedures, especially tonsillectomy, as it reduces postoperative pain, nausea and vomiting, and airway swelling, while increasing oral intake (
12,
13). However, there is a lack of studies that have investigated the effects of this drug on other common complications like otalgia, odynophagia, and halitosis. Thus, in this randomized controlled clinical trial, we investigated the effects of dexamethasone after adenotonsillectomy in terms of postoperative nausea and vomiting, pain, and bleeding, as in previous studies, as well as odynophagia, otalgia, halitosis, voice change, and activity or healthiness, which were not evaluated in previous research. Faiz et al. compared the effects of intravenous acetaminophen or dexamethasone in their randomized controlled trial study. They concluded that dexamethasone had more advantages in comparison to acetaminophen for inhibiting postoperative pain and nausea and vomiting following tonsillectomy in children (
13). They also showed that glucocorticoids like dexamethasone decrease the degree of inflammation via the inhibition of bradykinin, prostaglandin, and leukotrienes, leading to a decrease in accompanying signs and symptoms, including pain (
16). We can state that the reductions in postoperative pain, odynophagia, and otalgia may be attributed to the anti-inflammatory effect of dexamethasone, which may decrease local edema and pain. The association of paediatric anaesthetists of great Britain and Ireland concluded that in patients undergoing tonsillectomy, dexamethasone 15 mg/kg provided good reduction in postoperative vomiting with no adverse effects (
17). In addition, in 2013, Muhammad et al. designed a study to compare the effectiveness of gastric suction and a single dose of dexamethasone in reducing post-tonsillectomy vomiting in children. Their results indicated that a single dose of dexamethasone can decrease the frequency of postoperative vomiting in children (
11). Dexamethasone exerts its antiemetic effect through the inhibition of serotonin, release of endorphins, and antagonism of prostaglandin (
15). In accordance with the previous studies, our results indicated that dexamethasone decreased the incidence of postoperative nausea and vomiting in adenotonsillectomy. In a study conducted by Czarnetzki et al. their results indicated a significant and dose-dependent decrease in the incidence of postoperative nausea and vomiting in children undergoing tonsillectomy with administration of dexamethasone. Dexamethasone also decreased the need for rescue analgesia with ibuprofen. However, it was associated with a significant increase in the risk of postoperative bleeding (
1).The results of our study and those of Czarnetzki et al. research revealed that dexamethasone increases the risk of bleeding (
1). The most convincing biological explanation for this might be related to the inhibition of the wound healing process by glucocorticosteroids (
18). Dexamethasone inhibits factors that regulate the healing process, such as epidermal and basic fibroblast growth factors (
19,
20). In addition, dexamethasone decreases the deposition of collagen, epithelization, and fibroblast content of surgical wounds (
21). In contrast, our results indicated that the difference in the incidence of bleeding between the case and control groups was not significant. Thus, further randomized trials that are specifically designed to confirm or refute our findings are needed, although it may be difficult to perform adenotonsillectomy trials in children. Finally, this study showed that dexamethasone significantly decreased the incidence of postoperative nausea and vomiting, pain, odynophagia, and otalgia in children undergoing tonsillectomy. In addition, it decreased the need for analgesia with acetaminophen. However, dexamethasone was associated with an increase in the risk of postoperative bleeding. It should be mentioned that the limited number of patients represents a limitation of our study. We suggest more research to compare dexamethasone with other drugs and evaluate their effects on postoperative complications after tonsillectomy in children. In conclusion, in children undergoing adenotonsillectomy, dexamethasone has a significant antiemetic effect and decreases odynophagia, otalgia, and the need for analgesia.