The effect of dilution and prolonged injection time on dexamethasone-induced perineal pruritus

• Published in: Pharmazie Vol. 67; no. 12; pp. 1015 - 1017
• Main Authors: Gu, C Y, Wu, Y M, Zhou, M T, Li, F, Tang, Q F
• Format: Journal Article
• Language: English
• Published: Germany Govi-Verlag 01.12.2012
• Subjects: Adult; Aged; Anesthesia; Anti-Inflammatory Agents - administration & dosage; Anti-Inflammatory Agents - adverse effects; Dexamethasone - administration & dosage; Dexamethasone - adverse effects; Double-Blind Method; Female; Humans; Injections, Intravenous; Male; Middle Aged; Perineum; Pharmaceutical Solutions; Pruritus - chemically induced; Pruritus - diagnosis; Pruritus - prevention & control; Sex Characteristics; Young Adult
• ISSN: 0031-7144
• DOI: 10.1691/ph.2012.2651

Dexamethasone has been widely used before general anesthesia induction. However, previous studies have found that a pre-induction bolus dose of dexamethasone sometimes causes perineal pruritus. We hypothesized that an appropriate prolongation of the injection time might suppress dexamethasone-induced perineal pruritus. Four hundred patients requiring general anaesthesia were randomly allocated into four groups: group I receiving 2 ml dexamethasone (5 mg/ml); group II receiving 4 ml dexamethasone (2.5 mg/ml); group III receiving 10 ml dexamethasone (1 mg/ml); and group IV receiving 20 ml dexamethasone (0.5 mg/ml). Dexamethasone was diluted with 0.9% sodium chloride. The injection time of dexamethasone was 5 s in groups I, II and III; while the injection time of dexamethasone was 30 s in group IV. Occurrence of perineal pruritus was significantly reduced in Group IV (0% vs 38%, 32% and 12% in Groups I, II and III, respectively, p < 0.05). The incidence was higher in females than in males (p < 0.05). The duration of perineal pruritus was longer in females than in males in groups I, II and III (p < 0.05). We conclude that the dilution of dexamethasone to 0.5 mg/ml with 0.9% sodium chloride combined with prolonged injection time to 30 s eliminates dexamethasone-induced perineal pruritus.