Comparative Study of the Adverse Events Associated With Adjuvant Use of Dexmedetomidine and Clonidine in Local Anesthesia

Background: Although clonidine and dexmedetomidine are used as alpha-2 agonists to improve the quality and duration of blockade induced by local anesthetics, no study has been reported to compare their associated adverse events in local anesthesia. The aim of this study is to compare the adverse events associated with the adjuvant use of dexmedetomidine and clonidine in local anesthesia. Methods: A comprehensive search was performed to retrieve any reported adverse event associated with adjuvant use of dexmedetomidine and clonidine in local anesthesia from published literature up to 1 July 2020. Assessment of the quality of included studies was performed by the Jadad score. A comparison of any reported adverse event was made between interventions by pooling data from studies using a direct meta-analysis technique. Dichotomous outcomes were summarized as risk ratios. The review was performed according to PRISMA guideline. Results: From 121 articles retrieved from the search finally 14 articles including 1,120 patients had eligibility criteria for including in the meta-analysis. No significant difference was observed between bradycardia/hypotension (OR = 1.17; 95 % CI = 0.66–2.10; P = 0.580; I(2) = 53.78 %, P = 0.027), nausea/vomiting (OR = 0.91; 95% CI = 0.59-1.42; P = 0.706; I(2) = 0.0 %, P = 0.940) dizziness/headache (OR = 1.10; 95% CI = 0.44–2.75; P = 0.831; I(2) = 0.0 %, P = 0.882) shivering (OR = 0.95 % CI = 0.50–1.66; P = 0.831; I(2) = 0.0 %, P = 0.920) and dry mouth (OR = 1.00; 95 % CI = 0.50–1.96; P = 0.996; I(2) = 0.0%, P = 0.900). No significant difference was observed in subgroup comparison of adverse events in the intravenous or local adjuvant use of the study drugs (p > 0.05). Conclusion: There is no difference in adverse events associated with the intravenous or local adjuvant use of dexmedetomidine and clonidine in local anesthesia.