Efficacy and safety of epidural clonidine by continuous infusion or patient-controlled analgesia in labor: A meta-analysis of randomized controlled trials

Int J Gynaecol Obstet. 2023 Jun;161(3):726-737. doi: 10.1002/ijgo.14579. Epub 2022 Nov 28.


Background: Epidural clonidine improves analgesia but may induce adverse effects in labor.

Objective: To evaluate the efficacy and safety of epidural clonidine as local anesthetics (LA) adjuvant by continuous infusion or patient-controlled epidural analgesia (PCEA) in labor.

Search strategy: PubMed, Embase, Web of Science, and CENTRAL were searched from inception to May 10, 2022 without language restriction; references of the retrieved studies were hand searched.

Selection criteria: Randomized controlled trials (RCTs) comparing epidural LA with and without clonidine using continuous infusion or PCEA in labor were included.

Data collection and analysis: A random effects model was used to pool the data on analgesia and adverse effects.

Main results: Eight RCTs were included. Clonidine did not reduce the incidence of parturients requiring additional epidural boluses but reduced LA consumption and pain scores without increasing adverse effects, except for a higher incidence of instrumental delivery when clonidine was combined with LA and opioid (risk ratio 2.38, 95% confidence interval 1.26-4.50). Clonidine offered similar analgesia to opioids but had reduced opioid-related adverse effects. Trial sequential analysis showed that the evidence was insufficient.

Conclusions: Epidural clonidine by continuous infusion or PCEA does not increase significant adverse effects and offers similar analgesia to opioids in labor. PROSPERO registration no. CRD42022306565.

Keywords: clonidine; epidural analgesia; labor pain; meta-analysis; systematic review.

Publication types

  • Meta-Analysis
  • Review

MeSH terms

  • Analgesia, Epidural* / adverse effects
  • Analgesia, Obstetrical* / adverse effects
  • Analgesia, Patient-Controlled / adverse effects
  • Analgesics, Opioid / adverse effects
  • Anesthetics, Local / adverse effects
  • Clonidine / adverse effects
  • Female
  • Humans
  • Pregnancy
  • Randomized Controlled Trials as Topic


  • Analgesics, Opioid
  • Anesthetics, Local
  • Clonidine