Absence of histological changes after the administration of a continuous intrathecal clonidine in Wistar rats.
BACKGROUND
The administration of epidural and spinal clonidine has demonstrated an antinociceptive effect in animals and humans. For that reason, its spinal administration has been proposed as an adjuvant in chronic pain management. However, there is limited information about its possible neurotoxic effect after its continuous neuraxial administration.


METHODS
Twelve male Wistar rats were randomly divided into two groups. Using an osmotic mini-pump a continuous infusion of intrathecal clonidine, (21.4 micrograms/day, Group A) or saline solution (Group B), was administered for 14 consecutive days. For evaluating the neurological damage a neuropathological analysis of the spinal cord was performed by light microscopy.


RESULTS
Neurohistopathologic examination of the spinal cord specimens failed to show evidence of neurotoxic damage in either group.


CONCLUSIONS
These findings showed that continuous intrathecal administration of clonidine did not produce evidence of histological neurotoxicity; therefore it is possible that continuous administration of intrathecal clonidine might be a safe option for treatment of chronic intractable pain; however, further investigations are necessary for evaluating diverse doses and periods of time, and to define its possible behavioral effects.
Guevara-López
Uriah
U
Departamento de Medicina del Dolor y Paliativa, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico. uriahguevara@hotmail.com
Aldrete
J Antonio
JA
Covarrubias-Gómez
Alfredo
A
Hernández-Pando
Rogelio E
RE
López-Muñoz
Francisco J
FJ
D000700:Analgesics / Q000008:administration & dosage*; D000818:Animals; D003000:Clonidine / Q000008:administration & dosage*; D004334:Drug Administration Schedule; D005911:Gliosis / Q000139:chemically induced; D007278:Injections, Spinal / Q000379:methods; D008297:Male; D009186:Myelin Sheath / Q000187:drug effects / Q000473:pathology; D020258:Neurotoxicity Syndromes / Q000209:etiology / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000187:drug effects* / Q000473:pathology*; D013223:Statistics as Topic
D000700:Analgesics; D003000:Clonidine