vomiting center reticular formation chemoreceptor trigger zone area

噁心、嘔吐的病態生理 嘔吐中心 (vomiting center) 位於延腦之reticular formation 接受來自多方刺激: 化學受體觸發地帶(chemoreceptor trigger zone) area postrema, 第四腦室底部 血腦屏蔽之外 (fenestrated venules) 上消化道和咽喉 前庭受器(vestibular apparatus) 大腦皮質中心

牽涉嘔吐之神經傳導物質/受體 Histamine (H 1 receptor) Acetylcholine (muscarinic- cholinergic receptors) Dopaminergic (D 2 receptor) Serotonergic (5 -HT 3 receptor) Neurokinin (NK-1 receptors)

STIMULUS AREA Drugs, Metaboli c Motion/ Position Viscer al ICP RECEPTORS Chemorecepto D 2 5 HT NK 1 r trigger zone Vestibul H 1 M ar Abdomin al organs Corte x D 2 H 1 VOMITING CENTRE 5 HT H 1 D 2 Dopamine 5 HT Serotonin H 1 Histamine NK 1 Neurokin 5 HT M EFFECTO R ORGANS M Muscarinic

化學治療藥物： 高致吐性 Cisplatin Dacarbazine Actinomycine-D Mechlorethamine Streptozocin Hexamethylmelamine Carboplatin Cyclophosphamide Oxaliplatin Lomustine Carmustine Daunorubicin Doxorubicin Epirubicin Idarubicin Cytarabine Ifosfamide

化學治療藥物： 中等致吐性 Irinotecan Mitoxantrone Paclitaxel Docetaxel Mitomycin Topotecan Gemcitabine Etoposide Teniposide Temozolomide

化學治療藥物： 低致吐性 Vinorelbine Fluorouracil Methotrexate Thioguanine Mercaptopurine Bleomycin L-asparaginase Vindesine Vinblastine Vincristine Busulphan Chlorambucil Melphalan Hydroxyurea Fludarabine

止吐藥的主要分類 Class Drug Anti-cholinergic scopolamine (L-hyoscine) Anti-histamine cyclizine dimenhydrinate Dopamine antagonist haloperidol Benzodiazepine lorazepam Corticosteroid dexamethasone Prokinetic metoclopramide, cisapride Neurokinin antagonist aprepitant 5 HT 3 -receptor antagonist granisetron, ondansetron tropisetron

止吐劑使用範例 • haloperidol 0. 5 - 1 mg po/sc/iv q 6 -12 h DOPAMINE ANTAGONISTS • prochlorperazine 5 - 20 mg po/iv q 4 -8 h • metoclopramide 10 - 20 mg po/sc/iv q 4 -8 h ANTIMUSCARINIC • scopolamine patch PROKINETIC • metoclopramide 10 - 20 mg po/sc/iv q 4 -8 h • cisapride 10 mg po tid-qid

止吐劑使用範例 • dimenhydrinate 25 - 100 mg po/ sc/ iv q 4 -8 h H 1 ANTAGONISTS • cyclizine 25 mg po/ sc/ im q 6 -12 h SEROTONIN • ondansetron 4 - 8 mg bid-tid po/sc/iv ANTAGONISTS • granisetron 0. 5 – 1 mg po/sc qd - bid MISCELLANEOUS • dexamethasone 2 - 4 mg po/sc/iv qd-qid • lorazepam 0. 5 - 1 mg po/sc q 4 -12 h

化療引發的急性嘔吐之預防 高度嘔吐危險的病患 單劑處方: Either Granisetron 3 mg iv Ondansetron 8 -32 mg iv Plus Dexamethasone 20 mg po/iv or Methylprednisolone 40 to 125 mg

化療引發的急性嘔吐之預防 中度嘔吐危險的病患 Dexamethasone 4 to 8 mg po 低度嘔吐危險的病患 Pretreatment not recommended

新藥物用於 Cisplatin 類化療藥物引發的遲發 性嘔吐之預防 抗NK 1 接受器 (aprepitant ) aprepitant 125 mg before cisplatin 80 mg on days 2 to 5 plus Ondansetron 32 mg dexamethasone 20 mg before cisplatin 8 mg on days 2 to 5

適用於臟器起因之噁心、嘔吐藥物 利用prokinetic 藥物 於胃腸蠕動停 Antihistamine藥物優於anticholinergic藥 物 可皮下施打 cyclizine, haloperidol, scopolamine, hyoscine butylbromide