Evaluation of possible spinal neurotoxicity of clonidine

An experimental investigation was carried out concerning the potential neurotoxic effects of clonidine. For this purpose intrathecal or extradural catheters were implanted in dogs. Clonidine at a dose level of 25 micrograms/kg or 12.5 micrograms/kg, or placebo, was then administrated via the catheter once daily for 14 consecutive days. The spinal cord and the nerve roots were then taken for neuropathological analysis. Observation of the neurological behaviour of the animals and the results of the morphological investigation support the conclusion that clonidine under these circumstances does not have any significant neurotoxic effects.