Intravenous dexamethasone has been used clinically to reduce surgical pain. Our study aims to investigate the analgesic efficacy, optimal dosage, mechanisms, and effects on surgical wound healing of dexamethasone in an animal postoperative pain model. We first converted 2 commonly used doses of dexamethasone in humans (8 mg and 16 mg) to their rat equivalent doses (0.24 mg and 0.47 mg). Rats then received hind paw incision with either saline, 0.24 mg or 0.47 mg dexamethasone injections. Subsequently, we compared degrees of mechanical and thermal allodynia by the Von Frey Test and the Thermal Place Preference Test. We then performed molecular tests and H&E staining of the hind paw sample to further determine dexamethasone’s effect locally. Blood glucose and body weight were also measured to delineate its systemic effect. Both 0.24 mg (p 0.05). There was significant weight loss in rats receiving dexamethasone (p < 0.05). Although dexamethasone was effective in pain control, using a moderate dose was non-inferior to a high dose. However, use of higher doses was associated with slower wound healing. Hence, our results in an animal model of acute postoperative pain suggest that using a moderate dexamethasone dose (8 mg) in humans may provide a better balance between analgesic efficacy and effects on wound healing.
Cheung et al. (2026) studied this question.