Gordh T, Hartvig P
Ups J Med Sci. 1986;91(3):311-5. doi: 10.3109/03009738609178671.
Epidural clonidine is an alternate way to treat severe pain in man. The cerebrospinal fluid (CSF) and plasma concentrations resulting after epidural, intravenous (i.v.) or intramuscular (i.m.) clonidine, 3 ug/kg b.w. have been determined by a sensitive gas chromatographic method. A porcine model was used, where the epidural and intrathecal spaces were cannulated via the atlanto-occipital membrane. After epidural administration of clonidine the CSF concentrations were maximal 20 minutes after the injection, 129 +/- 24 ng/ml (mean +/- S.D.). Clonidine was eliminated from CSF with an apparent half-life of 26 +/- 8.2 minutes (mean +/- S.D.). The plasma concentrations stayed below 1 ng/ml. Low plasma and undetectable CSF concentrations resulted after i.v. clonidine. Thus, epidural clonidine readily penetrates the dura mater into the CSF, and there is a marked gradient between CSF and plasma.
硬膜外给予可乐定是治疗人类重度疼痛的一种替代方法。通过一种灵敏的气相色谱法测定了给予体重3μg/kg的可乐定后，硬膜外、静脉内（i.v.）或肌肉内（i.m.）给药后产生的脑脊液（CSF）和血浆浓度。使用了猪模型，通过寰枕膜将硬膜外和鞘内空间插管。硬膜外给予可乐定后，注射后20分钟CSF浓度最高，为129±24 ng/ml（平均值±标准差）。可乐定从CSF中消除，表观半衰期为26±8.2分钟（平均值±标准差）。血浆浓度保持在1 ng/ml以下。静脉内给予可乐定后，血浆浓度低且CSF浓度检测不到。因此，硬膜外给予可乐定很容易穿透硬脑膜进入CSF，并且CSF和血浆之间存在明显的梯度。
