神经病性疼痛和辅助镇痛剂的意义NeuropathicpainandthemeaningofadjuvantanalgesicsDr.Z.ZyliczHospiceintheWealdPembury,TunbridgeWellsKent,UK“自然”疼痛的两种类型•适应性疼痛-“正常”的疼痛，•疼痛有助于维护躯体的整合（自闭，总是准备，“急性疼痛”大部分与A-δ纤维相关）•疼痛促进康复：“不要移动你断了的腿”，炎性疼痛，“慢性疼痛”大部分与C纤维有关Twotypesof“natural”pain•Adaptationpain–“normalpain”,•Thepainhelpstopreservebody’sintegrity(withdrawal,alwaysready,“fastpain”mostlyAdeltafibres）•Thepainpromotesrecovery:“donotmoveyourbrokenleg”,inflammatorypain,“slowpain”mostlyCfibres感受伤害性的疼痛Nociceptivepain炎性疼痛Inflammatorypain痛觉过敏“病理性疼痛”•与适应性无关•“病理性疼痛”，“没有目的的疼痛”•常常是神经病性源性•对经典镇痛剂没有或部分敏感•对辅助镇痛剂常常敏感“pathologicpain”•hasnothingtodowithadaptation•“pathologicpain”,“painwithoutpurpose”•frequentlyofneuropathicorigin,•notoronlypartiallysensitivetoclassicalanalgesics•frequentlysensitivetoadjuvantanalgesics神经病性疼痛Neuropathicpain痛觉过敏神经病性疼痛的2种类型Twotypesofneuropathicpain•Neurogenicpain神经源性疼痛–pressureonthenerve神经受压迫–peripheralsensitization外周神经敏化–Reversible可逆转性–distaltothedamage末稍损伤–partiallysensitivetoanalgesics对镇痛剂部分敏感–respondstolocalanaethetics对局部麻醉剂有反应–nerveentrapment神经的压迫性损害•Trueneuropathicpain真性神经病性疼痛–damageirreversible不可逆损伤–centralsensitization(spinalcord,brain)中枢神经敏化（脊索，脑）–classicalanalgesicsandanestheticsfrequentlyineffective普通镇痛剂和麻醉剂常常无效–adjuvantanalgesicslikeTCAareeffective辅助镇痛剂有效，如TCA类–nervesection神经切除背角的初级传入纤维的正常终端神经损伤以后，C纤维终端萎缩而A纤维终端长入后角表层“辅助性镇痛剂…”•所有的药物，包括尚未被许可用于治疗疼痛，但对于改善镇痛质量有用的药物。这些药物可能有经典镇痛剂的内在镇痛活性或潜在活性，或减低经典镇痛剂的毒性作用。“Adjuvantanalgesics…”•Alldrugs,notlicensedassuchforthetreatmentofpain,butusefultoimprovethequalityofanalgesia.Theymayhaveanintrinsicanalgesicactivityormaypotentiatetheactivityofclassicalanalgesicsordiminishtheirtoxiceffects.我们将讨论哪些药物？Aboutwhichdrugswearetalkingabout?•Antidepressants抗抑郁剂•Anxiolytics抗焦虑剂•Anticonvulsants抗惊厥药物•NMDAinhibitorsN-甲基-D-天冬氨酸抑制剂类•Musclerelaxants肌肉松弛剂•Psychostimulants精神兴奋剂•Neuroleptics精神抑制剂•Corticosteroids糖皮质激素抗抑郁剂Antidepressants•amitriptylline(Tryptizol®)阿米替林•imipramine(Tofranil®)丙咪嗪•Venlafaxine(Efexor®)文拉法辛•Paroxetine(Seroxat®)帕罗西汀•Mirtazapine(Remeron®)米氮平阿米替林与安慰剂amitryptyllineversusplacebo,HJMcQuay1999抗焦虑剂（咪达唑仑®）•低剂量时与阿片类药物的协同作用•抗焦虑作用的辅助镇痛作用•高剂量时的过度镇静作用•与抗惊厥药物同用时，其代谢机制不同•吗啡与咪达唑仑同用时,其剂量明显减少•内在抗惊厥活性（作为盖巴喷丁的替代药物是有用的）Anxiolytics(Midazolam®)•inlowdosesynergisticwithopioids•anxiolyticeffectusefulinanalgesia•inhighdosesedatives•metabolismisvariableinpresenceofanticonvulsantdrugs•morphinedosesignificantlylowerwhenusedwithmidazolam•intrinsicanticonvulsantactivity(usefulasreplacementofgabapentin）.抗惊厥药物Anticonvulsants•carbamazepin(Tegretol®)卡马西平•phenytoin(Difantoine®)苯妥英•valporoicacid(Depakine®)丙戊酸•clonazepam(Rivotril®)氯硝安定•lamotrigine(Lamictal®)...
