Background: Clonidine is used as adjuvant to local anaesthetics for spinal anaesthesia. Its potential harm and benefits have not been systematically reviewed in obstetrics, and medical regulatory authorities do not recommend its intrathecal administration. The aim of this study was to assess the safety and efficacy of intrathecal clonidine for caesarean delivery.

Methods: We conducted a systematic literature search in Medline, Embase, the Cochrane Library databases and trial registries for randomised trials assessing intrathecal clonidine as an adjuvant to local anaesthetics in patients undergoing caesarean delivery. Studies were assessed for quality, and data were extracted on study characteristics, safety and efficacy. Pooled data analysis using random-effects models was performed. Relative risk (RR) or mean difference with 95% confidence intervals (CI) were used to analyse outcomes.

Results: Of 201 reports screened, 12 relevant clinical trials were included. Clonidine prolonged the duration of sensory block by 128.2min (95% CI 81.7 to 174.8) and motor block by 44.7min (95% CI 8.7 to 80.7). Clonidine increased sedation, RR 3.92 (95% CI 1.17 to 13.14), but did not increase the risk of hypotension, pruritus or postoperative nausea and vomiting. Apgar scores at 1 or 5min were not influenced by the addition of intrathecal clonidine.

Conclusion: Clonidine is an effective and safe adjuvant to local anaesthetics for spinal anaesthesia for caesarean delivery. This opens the debate as to whether intrathecal clonidine as an "off label" prescription should be reconsidered by medical regulatory authorities.