Extradural Clonidine Does Not Potentiate Analgesia Produced by Extradural Morphine After Meniscectomy

Abstract

We have studied the ability of clonidine to potentiate morphine analgesia in 28 patients (ASA I) after meniscectomy under general anaesthesia. One hour after surgery, morphine 3 mg (n = 10), clonidine 75 micrograms (n = 8) or morphine 3 mg plus clonidine 75 micrograms (n = 10) was injected extradurally. Morphine alone and in combination with clonidine produced similar and significant analgesia as assessed by verbal analogue pain scores. Pain scores did not decrease significantly in patients given clonidine alone. There were statistically, but not clinically significant decreases in systemic arterial pressure after morphine alone and clonidine alone. No patient developed sensory or motor block. One patient given morphine alone developed retention of urine. It is concluded that, in the dose used in this study, clonidine did not potentiate the analgesia produced by extradural morphine.

Alpha2‐adrenergic agents in anaesthesia

“…Similarly, epidural clonidine (3 pg/kg) was insufficient for postthoracotomy pain (141). A single small dose (75 pg) of epidural clonidine was unsatisfactory alone for postoperative analgesia after knee surgery, neither did it potentiate the analgesia produced by extradural mor-phine ( 142). Nevertheless, the authors of several investigations have suggested that epidural a,-agonists may provide an effective alternative or an adjunct to opioid therapy in the management of pain and that a,agonists may be especially useful in those forms of pain that are resistant to opioids (134,137,141,143).…”

Spinal agents for acute pain management

“…A number of studies have examined the delivery of combinations of clonidine with morphine, fentanyl, or sufentanil for the treatment of acute pain [7,28,[30][31][32].…”

Analgesie und Hämodynamik unter 8 μg/kg Clonidin epidural zur Schmerztherapie nach großen abdominellen Eingriffen

“…Unser Ergebnis ist mit denjenigen anderer Studien mit hohen Clonidindosen (13,20) vergleichbar und bes ser als das nach niedrigen (2-3 pg/kg) Dosen (2,12,17,19). in der Literatur wird nach 75 pg Clonidin epidural keine Veränderung der Herzfrequenz beobachtet (28), nach 2pg/kg (29) und 3 pg/kg (12) bleibt die HR ebenfalls stabil, während nach 6-10 pg/kg HR-Abfälle häufig und teilweise therapiewürdig sind (13,20). Nach 300pg Clonidin p. o. oder i. V. wer-den milde Abfälle der Herzfrequenz beobachtet (3, 19).…”