Ketamine has been used in combination with a
variety of other agents for intra-articular analgesia, with promising results.
However, although it has been shown to be toxic to various types
of cell, there is no available information on the effects of ketamine
on chondrocytes. We conducted a prospective randomised controlled study to evaluate
the effects of ketamine on cultured chondrocytes isolated from rat
articular cartilage. The cultured cells were treated with 0.125
mM, 0.250 mM, 0.5 mM, 1 mM and 2 mM of ketamine respectively for
6 h, 24 hours and 48 hours, and compared with controls. Changes of
apoptosis were evaluated using fluorescence microscopy with a 490
nm excitation wavelength. Apoptosis and eventual necrosis were seen
at each concentration. The percentage viability of the cells was
inversely proportional to both the duration and dose of treatment
(p = 0.002 and p = 0.009). Doses of 0.5 mM, 1 mM and 2mM were absolutely
toxic. We concluded that in the absence of solid data to support the
efficacy of intra-articular ketamine for the control of pain, and
the toxic effects of ketamine on cultured chondrocytes shown by
this study, intra-articular ketamine, either alone or in combination
with other agents, should not be used to control pain. Cite this article: