[Peripheral analgesic effect of intra-articularly applied clonidine].
OBJECTIVE
Clonidine applied intra-articularly into the knee joint has a peripheral analgesic effect. We examined intra-articularly injected clonidine to determine whether resorption with a measurable systemic concentration could be detected.


METHODS
A randomised, placebo-controlled double-blind study was carried out on patients undergoing knee arthroscopies. The 69 patients were randomised into three groups: group 1 received 150 ug clonidine intra-articularly, group two 150 ug clonidine intravenously and group three a placebo. Postoperative pain therapy was carried out with i.v. morphine hydrochloride. Pain scores and side-effects were documented for 24 h.


RESULTS
There were no significant differences between the three groups in demographics, duration of operation, duration of anaesthesia, diagnoses or type of operation. The pain score at rest was significantly lower in group 1. In the first 20 min, the systemic concentration of clonidine was significantly higher in the intravenous group than in the intra-articular group.


CONCLUSIONS
Intra-articular clonidine has a postoperative analgesic effect after knee arthroscopies due to a peripheral action.
Sadjak
A
A
Institut für Pathophysiologie, Medizinische Universität Graz.
Wintersteiger
R
R
Zakel
D
D
Wenzl
T
T
Lankmayr
E P
EP
Gferer
E
E
Likar
R
R
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000494:pharmacology; D000698:Analgesia; D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology*; D001182:Arthroscopy; D003000:Clonidine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D004311:Double-Blind Method; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007270:Injections, Intra-Articular; D007719:Knee Joint; D010147:Pain Measurement; D010525:Peripheral Nerves / Q000187:drug effects / Q000503:physiopathology*; D010919:Placebos
D000316:Adrenergic alpha-Agonists; D000700:Analgesics; D010919:Placebos; D003000:Clonidine