<p>Comparison of subcutaneous dexmedetomidine versus clonidine as an adjuvant to spinal anestheia: a randomized double blind control trial</p>

Abstract

Background: Alpha-2 adrenergic agonists like clonidine and dexmedetomidine prolong the duration of postoperative analgesia and improve the quality of subarachnoid block (SAB) when used as adjuvant in various routes. However, addition of these drugs by IV or intrathecal routes are known to cause hemodynamic instability. The subcutaneous (SC) route provides similar efficacy as IV administration with less hemodynamic instability and prolonged effect. Aims : To compare the efficacy of clonidine and dexmedetomidine as adjuvants to SAB when used subcutaneously. Materials and methods: A total of 90 patients were randomized into one of the three groups: Group P received 1 ml of Normal saline SC, Group D received 0.5 mcg/kg of dexmeditomedine SC and Group C received 1 mcg/kg of clonidine SC respectively after SAB with 3ml of 0.5% hyperbaric bupivacaine (15 mg). Time of onset of sensory and motor block, intraoperative hemodynamics, postoperative VAS scores, Richmond agitation sedation scale, duration of postoperative analgesia and mean paracetamol requirement in 24 hours were recorded. Results: Mean duration of postoperative analgesia was prolonged in group D (838.10±348.22 minutes) and group C (816.67±230.48 minutes) when compared to group P (332.10±110.91 minutes). Total paracetamol consumption was less in group D (1400.00±770.13 mg) and group C (1600.00±674.66 mg), whereas it was 1900.00±758.86 mg in group P. Hemodynamic parameters, maximum sensory level attained, and time to attain maximum sensory levels were comparable among the two groups. Conclusion: Both subcutaneous clonidine and dexmedetomidine prolonged the duration of postoperative analgesia and reduced analgesic requirements when used as adjuvants to SAB with stable hemodynamics, hence both of these drugs can be used effectively as adjuvants to SAB.

Dexmedetomidine as an adjuvant for single spinal anesthesia in patients undergoing cesarean section: a system review and meta-analysis

“…Several studies had a similar result. 40,41 Gautam et al 42 suggested that dexmedetomidine is better than fentanyl as an intrathecal adjuvant to reduce visceral pain and in prolonged post-operative analgesia. Some studies considered that dexmedetomidine induces vasoconstriction by acting on the a2-adrenergic receptor to help prolong the period of analgesia, 43,44 while Yoshitomi et al 45 suggested that dexmedetomidine directly affects its ability via the a2-adrenergic receptor.…”

“…Several studies had a similar result. 40,41 Gautam et al. 42 suggested that dexmedetomidine is better than fentanyl as an intrathecal adjuvant to reduce visceral pain and in prolonged post-operative analgesia.…”

Review of clinical pharmacokinetics and pharmacodynamics of clonidine as an adjunct to opioids in palliative care

“…subcutaneous clonidine and dexmedetomidine prolonged the duration of post-operative analgesia and reduced analgesic requirements when used as adjuvants to subarachnoid block (SAB). 47 There is a case report that shows both the SC and TD routes are safe and viable options for treating dystonia pain with clonidine in the palliative setting. 48 A retrospective study review examined the SC route of administration in 113 patients (79/113 cancer) suffering from opioid poorly responsive pain (39), agitation or both ( 35) 8 (see Table 1).…”

“…In these tests, clonidine given subcutaneously was six to seven times more potent than morphine 46 . A study from Divya B showed that both subcutaneous clonidine and dexmedetomidine prolonged the duration of post‐operative analgesia and reduced analgesic requirements when used as adjuvants to subarachnoid block (SAB) 47 . There is a case report that shows both the SC and TD routes are safe and viable options for treating dystonia pain with clonidine in the palliative setting 48 .…”

Adjuvant Drugs to Local Anesthetics

“…It has been shown that clonidine and dexmedetomidine administered orally, intramuscularly, and intravenously also prolong the anesthetic effect of intrathecal LA [35][36][37][38][39][40].…”