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Pharmacy - sem2 > autacoid, depressant, Gl tract > Flashcards

autacoid, depressant, Gl tract Flashcards

1
Q

Receptors subtypes of histamine

A
  1. 受體subtypes：皆為G-protein

All G-protein mediated

  1. H1：位於皮膚、血管內皮、平滑肌、CNS ※ H1藥物專指抗組織胺
    • 增加細胞內Ca2+ via phosphoinositol hydrolysis
    • 產生血管、支氣管收縮
  2. H2：位於胃黏膜（gastric mucosa）、CNS、心肌（myocyte）
    • Adenyl cyclase-cAMP cascade → 產生胃酸
  3. H3：位於神經 (主要為前突觸presynaptic)
    • May be due to reduced Ca2+ influx
    • 減少neurotransmitters釋放
  4. H4：位於血球上 (mast cells, basophils)
    • Phospholipase C → 發炎反應
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2
Q

Storage of 5HT

A
  1. GI enterochromaffin cells：含有> 90%
  2. 血小板：帶著serotonin到處跑，佈滿全身，含量第二多 (carrier-mediated transport system)
  3. CNS
  4. High amount of 5-HT are found in raphe nuclei (located in pons/medulla)
  5. Projecting diffusely throughout the brain (cortex, hypothalamus, LS, hippocampus)
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3
Q

Area postrema

A

嘔吐相關，BBB最不完整處，所以會受血液中化學物質影響

5-HT3 receptors for the vomitting effect

antagonist of 5-HT3 could prevent vomitting

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4
Q

Autoreceptor for 5-HT

A
  1. *5-HT1A、5-HT1D可以做為autoreceptors，改變神經活性(負回饋降低活性)
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5
Q

Which subtypes of receptors of 5HT are ion channel based?

A

* only subtype 1A and 3 could act on ion channels; rest are all GP-Coupled!

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6
Q

How does 5HT causes vasodilation and vasoconstriction respectively? which receptor subtypes responsible for the actions?

A
  1. 若有完整血管內皮：smooth muscle being protected by endothelium; causing endothelium-mediated vasodilation by release of EDRF (NO)
  2. 若血管內皮受損：血小板凝集→釋放serotonin→serotonin和暴露出的血管smooth muscle作用→平滑肌收縮，止血(5-HT2)
  3. 若心血管疾病(僅次於癌症的第二大死因)、高血脂、高血糖、高血壓對細胞內皮造成傷害，血管內皮保護功能下降→產生不該有的血管收縮(在冠狀動脈就叫心絞痛)、Thrombus血栓(腦中風、心肌梗塞causes!!!!)
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7
Q

Thromboxane

A

factor released by the platelet, to cause vasoconstriction

vs prostacyclin (antagonist)

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8
Q

prostacyclin

A

factor released by the platelet, to cause vasodilation

vs thromboxane (antagonist)

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9
Q

Which receptor causes reflex bradycardia during injury??

A
  1. 5-HT3活化神經末梢carotid bodies
  2. 生理學角度：5-HT過高，代表有血管受傷、讓血流流速下降好讓血液凝集
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10
Q

Which receptor of 5HT responsible for platelet aggregation?

A

5-HT2A

platelet bring along a lot of 5HT (第二多5HT的地方，僅次於腸道）

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11
Q

effect of 5HT on stomach (+receptors information)

if carinoid tumor found in Gl tract, what may happen regarding 5HT??

A
  1. 5-HT2：smooth muscle收縮，刺激消化道神經節 (enteric ganglia cells)
  2. 5-HT4：Ach增加，促進消化道蠕動(prokinetic)
  3. Carcinoid tumor使serotonin大量產生，造成嚴重腹瀉
  4. 整體而言，對消化道增加運動性，增強功能
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12
Q

Prokinetic agent

A

Prokinetic agent means increasing the motility of Gl system

two ways: 1. inhibiting dopamine neuron, which inhibits Ach release

  1. increasing serotonin, because 5HT-4 promotes the release of Ach
  2. Metoclopramide(雙重機轉)：活化5-HT4、抑制D2R
  3. Cisapride：活化5-HT4
  4. Domperidone：抑制D2R
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13
Q

Metoclopramide

A
  1. 多重作用：D2 antagonist (also a tranquilizer! ) 及_5-HT4 agonist（主要）_
  2. 高劑量時為5-HT3 agonist (止吐）
  3. 可以穿透BBB (note domperidone cant！）
  4. antiemetic：block D2 receptor，達到中樞止吐作用
  5. Appetite stimulator (via on Gl emptying)
  6. 產生extrapyramidal side effects（EPS），和phenothiazines機制相似
  7. 副作用：EPS、腹痛、馬會中樞興奮、prolactin量增加（對乳癌、乳腺癌不利，因為會刺激乳腺細胞生長）
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14
Q

Cisapride

A
  1. Prokinetic agents：使myenteric motor neuron增加Ach釋放
  2. Cisapride：活化5-HT4
  3. 不影響dopamine及DA receptor的功能
  4. 為5-HT4 receptor agonist：使Ach釋放增加，促進腸胃道蠕動
  5. 也會block 5-HT3 receptor：有輕微止吐的效果
  6. 用於gastric/intestinal stasis腸胃滯留、reflux esophagitis逆流性食道炎、constipation便秘、megacolon巨結腸症的貓狗
  7. 副作用：腹瀉、腹痛
  8. 在少部分人身上會有嚴重的心律不整（原理不清楚）因此2000年開始就不用在人身上，以新藥mosapride取代。
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15
Q

Domperidone

A
  1. Prokinetic agents：使myenteric motor neuron增加Ach釋放（disinhibition：負負得正的概念）
  2. Domperidone：抑制D2R
  3. ***note dopamine is inhibitory to Gl system
  4. 因為不會穿過BBB所以沒有EPS（錐體外路徑）

注意: metoclopramide有EPS

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16
Q

What is the mechanism of causing chemically induced vomitting and nausea?

A
  1. 5-HT3活化消化道、area postrema(嘔吐感應區, 右圖)→嘔吐
  2. Ex.癌症化療引起嘔吐
  • CTZ (chemoreceptor trigger zone)有刺激性
  • mucosa受損（化療會攻擊快速分裂的細胞）→細胞死亡釋出5-HT→5-HT3活化嘔吐中樞
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17
Q

buspirone

A
  1. 屬於non-benzodiazepine anxiolytic drug
  2. 機制：5-HT1A receptor partial agonist
  • 副作用：很少；有少部分的貓攻擊性會增加
  • 用途：治療犬攻擊性、犬貓刻板行為、焦慮
  • 不影響GABA受體
  • 對重度焦慮、恐慌病患 (panic disorder) 無效
  1. 不會與其他鎮靜藥物交叉耐受 (cross-tolerance)
  2. 沒有抗癲癇和肌肉放鬆效果
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18
Q

sumatriptan

A
  1. 5-HT1B/1D Agonist
    1. 活化Autoreceptor：神經細胞活性下降，抑制促進發炎的neuropeptide釋放 (autoreceptor provides negative feedback!)
    2. 腦部intracranial血管收縮
    3. (acute anti-migraine agent)，對人重要 (過去使用ergot alkaloids/ergotamine麥角生物鹼，有全身性副作用)
  2. Clinical use: acute anti-migraine, and migraine induced nausea and vomiting
  3. 副作用小，2006年後為成藥over-the-counter migraine pill(不須醫師處方)
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19
Q

cyproheptadine

A
  1. Mechanism：Block H1、5-HT2
  2. 對H2沒有影響(腸胃道分泌)
  3. 第一代antihistamine：有__atropine-like significant副作用、引起鎮靜
  4. Clinical Use:
    1. Block 5-HT2：改善小兒和貓的食慾　(note serotonin is closely related to 感受認知情緒等等比較抽象的感覺)
    2. Block H1: feline pruritus, hives (allergy)
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20
Q

Ketanserin

A
  1. Mechanism: Block 5-HT1C、5-HT2、α1
  2. Clinical use: anti-hypertensive durg
    1. 5-HT2 blocking: 抑制血小板凝集→ antihypersensitive (but the effect is minor compared to alpha blocking)
    2. α1 blocking：effectively防止血管收縮 →降血壓(antihypertensive)、預防血栓

缺點：抑制太多種受體，選擇性不好，現在少用

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21
Q

Ritanserin

A
  1. Mechanism：Block 5-HT2
  2. 優點：沒有alpha blocking 所以more specific!!
  3. 缺點：影響血小板功能
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22
Q

Ondansetron

A
  1. 機制：Block 5-HT3
  • No effect on DA, H, adrenergic or cholinergic Rs
  • Clinical use: Prophylaxis & treatment of nausea and 嘔吐caused by 癌症化療、手術
  1. Pros:
  • 非常有效的antiemetics、
  • Specifically blocking 5-HT3副作用輕微 (not sedative, no influence on blood pressure, no dysphoria, extrapyramidal reactions, all are side effect of Phenothiazine)
  • 取代__phenothiazine or antihistamines

Cons: potential side effects include liver enzyme lifting and headache

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23
Q

Tropisetron

A
  1. 機制：Block 5-HT3
  2. Clinical use：
    1. 預防癌症化療、radio therapy、手術引起的vomiting/nausea
    2. Administered before麻醉誘導
    3. Managing symptoms induced by carcinoid syndrome (良性腫瘤)
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24
Q

granisetron

A
  1. Block 5-HT3
  2. Clinical use：
    1. 預防癌症化療、radio therapy、手術引起的vomiting/nausea
    2. Administered before麻醉誘導
    3. Managing symptoms induced by carcinoid syndrome (良性腫瘤)
  3. 優點：專一性更高 (compared to tropisetron)
    1.
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25
Q

dolasetron

A
  1. Block 5-HT3
  2. Clinical use：
    1. 預防癌症化療、radio therapy、手術引起的vomiting/nausea
    2. Administered before麻醉誘導
    3. Managing symptoms induced by carcinoid syndrome (良性腫瘤)
  3. 優點：專一性更高 (compared to tropisetron)
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26
Q

Ergotamine

A
  1. Ergotamine + caffeine：傳統用來治療偏頭痛 (migrane)，已被sumatriptan取代
  2. 副作用：使血管收縮 (影響周邊血流循環hypertension!)
  3. 自然界的serotonin agonist –Ergot alkaloids麥角生物鹼
  4. 在穀類上生長的黴菌所產生
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27
Q

Ergonovine

A

自然界的serotonin agonist –Ergot alkaloids麥角生物鹼

在穀類上生長的黴菌所產生

  1. Ergonovine (/ergometrine）+ oxytocin：促進子宮平滑肌收縮 (uterotonic effect)，抑制產後出血 (postpartum bleeding)
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28
Q

Ergovaline

A
  1. 牛毛草fescue grass被黴菌(acremonium coenophialum)寄生所產生
  2. Potent 5-HT2 agonist，對血管有強收縮作用
  3. 牛攝入後中毒→ergotism麥角生物鹼中毒
    1. 急性：牛變神經質、全身痙攣convulsion
    2. 慢性長期：壞疽gangrene due to 血液循環不良
    3. 牛泌乳（agalactia無乳）、繁殖量下降
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29
Q

endocannabinoids

A

內生性大麻

大麻藥理作用：促進食慾、止吐、加強嗎啡類止痛效果

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30
Q

pentagastrin

A

used for testing gastric acid secretion capability

more short acting than histamine, hence replacing it

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31
Q

betazole

A

isomer of histamine

now used to test for secretion capbility of the gastric acid secretion

historical: histamine

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32
Q

Cromolyn

nedocromil

A
  1. drug that 安定mast cell，減少histamine的釋放
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33
Q

what are the receptor responsible for causing nausea and vomiting

A
  1. motion sickness as only cause: CNS H1 receptor. Antihistamine of 1t generation should be used as drug
  2. chemotherapy / surgery as causes: 5-HT3 in area postremea, activating cheoreceptor trigger zone. 5HT3 antagonist should be used
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34
Q

cromolyn sodium

A
  1. 平時預防allergic rhinitis
    1. Route of administration鼻噴(nasal spray)
    2. Effect：穩定mast cell，防止活化

Pros: almost no side effect

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35
Q

promethazine

A

anti histamine + Phenothiazines

→本身是major tranquilizer，兼具抗組織胺，中樞抑制最明顯；也可以止吐

side effect:

  1. 鎮定、抑制中樞：疲乏、無精打采
36
Q

pyrilamine

A
  1. 高劑量pyrilamine最容易出現 –> 小孩、馬：部分出現中樞興奮
  2. belongs to ethylenediamines in structure
37
Q
  1. 過敏性鼻炎allergic rhinitis drug
A
  1. H1 antihistamines(標準用藥)→舒緩流鼻水、眼睛紅腫癢
  2. α-adrenergic agonists→嚴重鼻塞nasal congestion、流鼻水
    1. phenylephrine：pure α1 agonist
    2. 用鼻噴
  3. cromolyn sodium→平時預防
    1. Route of administration鼻噴(nasal spray)
    2. Effect：穩定mast cell，防止活化
    3. Pros: almost no side effect
  4. Glucocorticoid→嚴重症狀
    1. 最potent抗發炎藥物
    2. Route of administration：局部噴劑，嚴重時使用口服或注射，但會有全身性不良反應
  5. 免疫療法：注射少量已知過敏原，讓免疫系統造成immunal tolerance
38
Q

止吐用藥

A
  1. 針對藥物引起的 ： dopamine / 5HT3 antaonist
  2. motion sickness: histamine antagonist
39
Q

compare the potency of cimetidine Ranitidine, Famotidine, Nizatidine

What are them?? what are the首選用藥？waht are the side effect in common? who’ve got most and least side effect?

A
  1. all are H2 receptor antagonists/ H2 blockers
    1. 適應症：胃發炎、潰瘍、胃穿孔、胃食道逆流(效果較差)
    2. 動物胃酸是間歇式分泌，低劑量就有效
    3. 首選用藥：ranitidine、famotidine
    4. Potency：Famotidine > Nizatidine、Ranitidine > Cimetidine
    5. 副作用
      1. 一般副作用小，輕微可能腹瀉、頭痛、起疹子
      2. Cimetidine(Tagamet®)副作用最多，Nizatidine副作用最少
40
Q

Cimetidine

A
  1. 適應症：
  • Dogs and cats: 胃發炎gastritis、潰瘍gastric ulcer/erosions、胃穿孔、胃食道逆流 reflux esophagitis (效果較差), gastrinomas (會分泌過多胃酸；rare)
  • Horse and foals: gastritis and gastric erosions
    1. carnivores動物胃酸是間歇式分泌，低劑量就有效
    2. 副作用: 因耐受性很好，一般輕微：可能腹瀉、頭痛、rash (起疹子)
  • inhibition on P450 –> affect metabolism of other drugs
  • less potent than other inhibitor
  • lots of side effect: antiandrogen effect by binding androgen R that results in less sperm production
41
Q

Ranitidine

A
  1. H2 receptor blockers
  2. Mild effect on P450 (drug metabolism related)
  3. Prokinetic due to inhibition of chE
  4. intermediate potency
  5. first choice (famotidine too)
  6. 適應症：
  • Dogs and cats: 胃發炎gastritis、潰瘍gastric ulcer/erosions、胃穿孔、胃食道逆流 reflux esophagitis (效果較差), gastrinomas (會分泌過多胃酸；rare)
  • Horse and foals: gastritis and gastric erosions
  1. carnivores動物胃酸是間歇式分泌，低劑量就有效
  2. 副作用: 因耐受性很好，一般輕微：可能腹瀉、頭痛、rash (起疹子)
42
Q

Famotidine

A
  • H2 receptor blockers
  • no effect on P450 (drug metabolism related)
  • highest potency among four
  • first choice (ranitidine too)
  • side effect: hemolytic anemia in cat via IV
  • 適應症：
    • Dogs and cats: 胃發炎gastritis、潰瘍gastric ulcer/erosions、胃穿孔、胃食道逆流 reflux esophagitis (效果較差), gastrinomas (會分泌過多胃酸；rare)
    • Horse and foals: gastritis and gastric erosions
  • carnivores動物胃酸是間歇式分泌，低劑量就有效
  • 副作用: 因耐受性很好，一般輕微：可能腹瀉、頭痛、rash (起疹子)
43
Q

Nizatidine

A

H2 receptor blockers

no effect on P450 (drug metabolism related)

intermediate potency

適應症：

Dogs and cats: 胃發炎gastritis、潰瘍gastric ulcer/erosions、胃穿孔、胃食道逆流 reflux esophagitis (效果較差), gastrinomas (會分泌過多胃酸；rare)

Horse and foals: gastritis and gastric erosions

carnivores動物胃酸是間歇式分泌，低劑量就有效

副作用: 因耐受性很好，一般輕微：可能腹瀉、頭痛、rash (起疹子)

44
Q

Omeprazole

A
  1. H+ pump inhibitors [最有效]
    1. Mechanism: Covalently bind to (& kill) H+/K+ ATPase (non-reversible)
    2. Pros:
      1. 最有效的潰瘍治療藥物，直接破壞pump!
      2. 為前驅藥prodrug，進入胃中酸性環境後被活化才有效果→不影響其他組織 (nonacid-producing cells)，安全性很高!
  2. Cons：
    1. 但貴，屬後線藥物
    2. 抑制P450，影響部分藥物代謝 (BZDs、phenobarbital、phenytoin、warfarin)
  3. 用途
    1. Gastric & duodenal ulcers H2 blocker resistant：潰瘍
    2. Gastric esophageal reflux disease：胃食道逆流
    3. Gastric acid hypersecretory states：胃酸過度分泌
    4. NSAID induced gastric erosions：NSAID造成的消化道副作用
      1. NSAID抑制Prostaglandin(PG)產生
  4. 藥效和血中濃度無關； sloed accumulated in parietal cells
  5. 肝臟代謝，腎臟排出
45
Q

pantoprazole

A
  1. H+ pump inhibitors [最有效]
    1. Mechanism: Covalently bind to (& kill) H+/K+ ATPase (non-reversible)
    2. Pros:
      1. 最有效的潰瘍治療藥物，直接破壞pump!
      2. 為前驅藥prodrug，進入胃中酸性環境後被活化才有效果→不影響其他組織 (nonacid-producing cells)，安全性很高!
  2. Cons：
    1. 但貴，屬後線藥物
    2. 抑制P450，影響部分藥物代謝 (BZDs、phenobarbital、phenytoin、warfarin)
  3. 用途
    1. Gastric & duodenal ulcers H2 blocker resistant：潰瘍
    2. Gastric esophageal reflux disease：胃食道逆流
    3. Gastric acid hypersecretory states：胃酸過度分泌
    4. NSAID induced gastric erosions：NSAID造成的消化道副作用
      1. NSAID抑制Prostaglandin(PG)產生
  4. 藥效和血中濃度無關； sloed accumulated in parietal cells
  5. 肝臟代謝，腎臟排出
46
Q

Misoprostol

A
  1. Misoprostol (Cytotec®) [PGE1-like；cytoprotective 内生性的；胃酸抑制]
    1. Mechanism: PGE1類似物，拮抗EP3 receptor，降低cAMP釋出in parietal cells
    2. Dual effects：
      1. 減少胃酸分泌、
      2. 增加黏液mucin and bicarbonate分泌 (cytoprotective; PGE-like)
  2. Use: 預防NSAID造成的消化道副作用 (NSAID inhibits PG formation!)
  3. 副作用 (平滑肌收縮引起)
    1. 子宮收縮流產
    2. 腹瀉、腹痛abdominal pain、嘔吐
    3. 引起Inflammatory bowel disease(IBD)
  4. Contraindication：pregnancy / IBD patient
47
Q

Sucralfate

A
  1. Sucralfate [再受傷的地方形成cytoprotective polymer]
    1. 聚合物：polyaluminum hydroxide salt of sucrose sulfate
    2. Mechanism：在胃酸（pH<4）時形成黏膠狀polymer

→和黏膜潰瘍表面結合 (因含有Al salt，可幫助吸附到ulceration site)

  • (cytoprotective) (不抑制胃酸分泌)
    1. Pros: Al salt只有3%被吸收，對於腎功能正常病患不造成負擔
    2. 副作用
      1. 便祕constipation：Al吸收作用, 幫助糞便形成
      2. 腎功能不好無法排出Al，會腎衰竭

吸附其他藥，和其他藥物需間隔2 hr服用

48
Q

Bismuth

A
  1. Colloidal Bismuth鉍 【抓抓抓~protein coagulant】
    1. 常用藥：Bismuth subsalicylate
    2. Bismuth protein coagulant
      1. Mucus membrane
      2. 和pepsin結合，抑制pepsin活性
      3. 抓在潰瘍表面’s proteins，具有保護作用，避免受胃酸傷害
    3. 如有細菌：可抓住細菌！！有抗菌效果，可用於幽門螺旋桿菌感染
    4. 造成黑便(dark stool, not 血便)，需事先告知飼主
  2. 貓要注意：Subsalicylate一部分會轉換成salicylates，貓對水楊酸salicylates敏感，易中毒

PS

  • *Helicobacter hylori Infection
  • 使用Bismuth compound、抗生素、H2 antogonists、prazole等
  • Triple therapy：bismuth,、metronidazole、amoxicillin or tetracycline(抗生素)
49
Q

Sodium bicarbonate

NaHCO3

A
  1. 有效的制酸劑（oral）
  2. 臨床最常使用的尿液鹼化劑（IV injection）會使身體pH略為上升，多餘藥物快速從尿液排除（鹼化尿液）可以促進尿酸的溶解及排泄

使用太多可能造成systemic alkalosis（全身性鹼中毒）

50
Q

Aluminum hydroxide

Al2(OH)3

A
  1. 副作用：constipation便秘
  • 因為鋁有吸附作用造成
  • sucralfate也含Al3+，所以也會造成便秘
  1. 吸收不超過5%
  2. 腎功能差的不能使用，因為腎臟會無法代謝，造成毒性
51
Q

Magnesium hydroxide

Mg(OH)2

A
  1. 副作用：loose stool 軟便
    * 因為鎂會吸水份，讓糞便飽水
  2. Acid rebound：劑量不能太多，若一次中和太多胃酸會對胃造成刺激，胃反而會分泌更多胃酸。
  3. 氧化鎂MgO：最常使用的軟便劑，因為不會影響胃酸的分泌，所以經常性便秘通常都會處方MgO
52
Q

Al2(OH)3＋Mg(OH)2

A
  1. 最常將這兩種制酸劑合併，製成胃藥（胃乳片），因為可以平衡彼此的副作用
  • Al2(OH)3：便秘
  • Mg(OH)2：軟便
53
Q

MgO vs Mg(OH)2

A

氧化鎂MgO：最常使用的軟便劑，因為不會影響胃酸的分泌，所以經常性便秘通常都會處方MgO

54
Q

Laxatives vs

Cathartics

A

Laxatives：輕瀉劑，藥效較弱，有軟便效果

Cathartics：藥效較強，造成水瀉，可以排空大腸（手術前排空常用）

55
Q

蓖麻油

A

Castor oil蓖麻油：Irritant cathartics

  1. 刺激性瀉藥：刺激大腸黏膜而造成腸液分泌、排便反射（神經）
  2. 受lipase水解釋出ricinoleic acid，刺激腸道造成完全排空及水瀉
  3. 作用強烈所以在水瀉過程就會被排出，因此毒性較低
  4. 仍會引起腹痛，於反芻動物比較少用
56
Q

Diphenylmethane cathartic

A

Irritant cathartics藥物

  1. Diphenylmethane cathartic
  2. Phenolphthalein
  3. 可用於酸鹼滴定的指示劑
  4. 以前用在靈長類及豬的水瀉
  5. 因為發現有致癌性而少用了
  6. Bisacodyl
  7. 沒有致癌性
  8. 做成腸衣錠（enteric-coated）：
  • 在胃不會被溶解，因此對胃沒有刺激性
  • 有些藥對酸很不穩定，也需要用腸衣錠
  1. 直腸塞劑suppositories (enema)：效果比口服快
57
Q

Phenolphthalein

A

Irritant cathartics藥物

  1. Diphenylmethane cathartic
    1. 可用於酸鹼滴定的指示劑
    2. 以前用在靈長類及豬的水瀉
    3. 因為發現有致癌性而少用了
58
Q

Bisacodyl

A

Irritant cathartics藥物

  1. 沒有致癌性
  2. 做成腸衣錠（enteric-coated）：
  • 在胃不會被溶解，因此對胃沒有刺激性
  • 有些藥對酸很不穩定，也需要用腸衣錠
  1. 直腸塞劑suppositories (enema)：效果比口服快
59
Q

Anthraquinone cathartic

A
  1. 從含有anthraquinone（結構中含有醣苷類glycoside）的植物來的glycosides，如_aloe蘆薈、cascara鼠李皮、senna番瀉葉_
  2. Activation by bcateria: 在colon被腸道菌相分解成_aglycones (=anthraquinone,_ 把糖切掉) 才開始作用、刺激腸神經叢促進排便
  3. Colon toxicity (myenteric plexuses degeneration) after chronic use：

長期慢性使用會造成腸神經叢退化，以後就很難靠自己的力量排便

喔！！所以東東叮嚀：不要常吃促排便的東西，不管是不是天然萃

取的，長期下來都會導致腸神經退化。

60
Q

how dopamine and serotonin affect the Gl system?

A

Dopamine（抑制作用）【降低腸道運動神經的活性】

  1. D2 antagonist：活化D2 receptor造成Ach的釋放減少，腸胃蠕動的功能下降
    • 使用拮抗劑可以抑制D2 receptor對腸道運動神經的抑制，增加腸胃蠕動
  2. 降低胃腸道平滑肌張力（抑制作用）

5-HT agonist

  1. 是胃腸道中藥的自泌素autacoid
  2. 5-HT3 receptor及5-HT4 receptor是最重要的兩個receptor：
  3. 5-HT3 receptor被抑制時會有止吐效果

5-HT4 receptor被活化時會有促動效果(增加Ach的釋放)

61
Q

mosapride

A

cisapride在少部分人身上會有嚴重的心律不整（原理不清楚）因此2000年開始就不用在人身上，以新藥mosapride取代。

cisapride:

  1. 為5-HT4 receptor agonist：使Ach釋放增加，促進腸胃道蠕動
  2. 也會block 5-HT3 receptor：有輕微止吐的效果
  3. 用於gastric/intestinal stasis腸胃滯留、reflux esophagitis逆流性食道炎、constipation便秘、megacolon巨結腸症的貓狗
  4. 副作用：腹瀉、腹痛
62
Q

Erythromycin

A
  1. motilin-like effect
  2. motilin：為身體的hormone，刺激上消化道（胃、小腸）蠕動
  3. Erythromycin會產生類似motilin的效果，使上消化道快速收縮，對大腸直腸的影響相對較小
  4. Sub-antimicrobial doses (0.5-1 mg/kg, oral) are prokinetic in dogs & cats

在貓狗上，低於抗菌劑量下就有顯著的促動劑效果

  1. 促進胃的排空
  2. 可跟制酸劑合併使用在逆流性食道炎（胃食道逆流）

上消化道蠕動變快也會稍微影響到下消化道，所以當作抗生素使用時（劑量較高）容易出現消化道副作用

63
Q

scopolamine

A

anti-muscarinic drug responsible for controlling emesis associated with motion sickness

64
Q

Diphenhydramine

A

First generation antihistamine, for controlling emesis associated with motion sickness

can pass through BBB, so also have some sedative effect

65
Q

chlorpheniramine

A

First generation antihistamine,

can pass through BBB, so also have some sedative effect

66
Q

Promethazine

A

First generation antihistamine, for controlling emesis associated with motion sickness

can pass through BBB, so also have some sedative effect

也是phenothiazine!寧神效果更強

67
Q

cyclizine

A

First generation antihistamine, for controlling emesis associated with motion sickness

can pass through BBB, so also have some sedative effect

68
Q

meclizine

A

First generation antihistamine, for controlling emesis associated with motion sickness

can pass through BBB, so also have some sedative effect

69
Q

buclizine

A

First generation antihistamine, for controlling emesis associated with motion sickness

can pass through BBB, so also have some sedative effect

70
Q

Maropitant (Cerenia®)

A
  1. 新一代動物止吐藥
  2. NK1 receptor antagonist

＊Neurokinin（NK，又稱tachykinin）receptor是substance P的受器，

與疼痛有關，CNS與PNS都有分布

  1. 嘔吐中樞也有NK receptor，過強的疼痛會經此pathway引起嘔吐
  2. 貓、狗的止吐藥，人未核可
  3. 用於急性嘔吐的預防及治療
  4. motion sickness（暈車）的預防
  5. 貓使用xylazine引起的嘔吐也可使用maropitant止吐

主要由肝臟代謝

71
Q

xylazine and 吐吐吐

A
  1. centrally acting emetics: directly stimulate CTZ to cause vomiting
    嘔吐由 α2 receptor 調控，貓馬對其敏感：
  2. 貓催吐
  3. 馬則會不自主抽動，可能會踢傷獸醫
  4. 對狗較無效 30%
72
Q

吐根

A

Ipecac（吐根）syrup 糖漿或粉末

  1. 從吐根植物萃取的生物鹼emetine（吐根鹼）
  2. 可以殺阿米巴原蟲(amebicide)
  3. 同時刺激中樞和周邊神經，可以活化CTZ、chemoreceptor
  4. 曾用在人狗_貓_，但現在已停用，因為很難在藥量和藥效取得平衡，毒性可致死
73
Q

Apomorphine

A

centrally acting emetics中樞催吐劑

stimulate CTZ directly

  1. 最主要催吐藥物
  2. 構造似嗎啡，可以寧神但沒有止痛效果
  3. 少數貓使用後會中樞興奮
74
Q

樟腦鴉片酊

A

Paregoric 樟腦鴉片酊

鴉片類止瀉劑

  1. camphorated tincture of opium鴉片酊劑（鴉片+樟腦+酒精）
  2. 用在貓會中樞興奮à使用上仍有爭議
  3. 有成癮性，現在少用
75
Q

Diphenoxylate

A
  1. 鴉片類止瀉劑
  2. Meperidine 衍生物 (opioid that 造成最小的子宮收縮作用）
  3. 能穿越 BBB：有 CNS 副作用(中樞迷幻)，可能被濫用、有成癮性的問題
  4. Lomotil®：Diphenoxylate＋atropine以防止濫用：

成癮者要較大劑量才能有舒緩的效果，但atropine的副作用超多：抑制GI蠕動/分泌、副作用心悸、噁心、散瞳、排尿困難，高劑量會讓人不舒服

現在已被Loperamide取代

76
Q

高嶺土

A
  1. non-opioid 止瀉劑
  2. 自然產生含水矽酸鋁鹽 hydrated aluminum silicate
  3. 和果膠 pectin 結合成複方：kaopectin，變成有黏性的膠狀物質，具吸附壞菌＆毒素的效果、可以保護發炎的黏膜
  4. 對消化性潰瘍效果不好
  5. 是面膜的材料之一
77
Q

Cyproheptadine

A

Appetitde stimulator

  1. block histamine & 5-HT
  2. 用在兒童和貓
  3. 對狗無效
78
Q

how BZD stimulate appetite? any examples?

A
  1. Ex. diazepam & oxazepam
  2. GABA agonist：降低焦慮，抑制飽食中樞（satiety centerin hypothalamus）
  3. 常用在貓促進食慾，對狗較沒有效果
79
Q

Mirtazepine

A

人：tetracyclic antidepressant抗憂鬱 動物：食慾促進劑/止吐劑

  1. 機制＆作用（貓狗）：雜亂無比啊
    1. 增加NE釋放、5-HT2 antagonism：刺激食慾
    2. 5HT3, H1,　antagonism：止吐antiemetic
  2. 副作用：鎮靜（block H1）
80
Q

prednisolone

A

Glucocorticoids that stimulate appetite

  • Route of adminstration: PO
  • unclear mechanism 一般認為可能是因為抗發炎能減緩不適，讓胃口變好
  • 副作用：影響醣類代謝、胃潰瘍、免疫抑制、抗發炎（inhibiting　prostaglandin
  • as side effect too serious, so for short term use only
81
Q

dexamethasone

A

Glucocorticoids that stimulate appetite

  • Route of adminstration: IV （prednisolone PO)
  • unclear mechanism 一般認為可能是因為抗發炎能減緩不適，讓胃口變好
  • 副作用：影響醣類代謝、胃潰瘍、免疫抑制、抗發炎（inhibiting　prostaglandin
  • as side effect too serious, so for short term use only
82
Q

Poloxalene

A

Anti-bloat Agent by surfactant property

  1. Surfactant: 為乙烯(Ethylene)以及環氧丙烯(Propylene oxides)的polymer。
  2. 可以添加在飼料中或是直接灌藥。
  3. 幫助消化道氣體的聚集（把小泡泡聚合成爲大泡泡，讓其比較能夠逃出食物，排出身體）
  4. 脹氣（Bloat）以及鼓脹（Tympany）常見於ruminant的瘤胃內過度氣體聚集導致無法排出。
83
Q

Polymerized methyl silicone 聚甲基矽氧烷

A

Anti-bloat Agent by surfactant property

Surfactant: 為乙烯(Ethylene)以及環氧丙烯(Propylene oxides)的polymer。

可以添加在飼料中或是直接灌藥。

幫助消化道氣體的聚集（把小泡泡聚合成爲大泡泡，讓其比較能夠逃出食物，排出身體）

  1. 脹氣（Bloat）以及鼓脹（Tympany）常見於ruminant的瘤胃內過度氣體聚集導致無法排出。
84
Q

植物油(Vegetable oil)

A
  • Anti-bloat agent抗漲氣
85
Q

Azapirone

A
  1. 屬於non-benzodiazepine anxiolytic drug
  2. 機制：5-HT1A receptor partial agonist
  • 不影響GABA受體
  • 對重度焦慮、恐慌病患 (panic disorder) 無效
  • 不會與其他鎮靜藥物交叉耐受 (cross-tolerance)
  • 沒有抗癲癇和肌肉放鬆效果
  1. 副作用：很少；有少部分的貓攻擊性會增加
  2. 用途：治療犬攻擊性、犬貓刻板行為、焦慮

Pharmacy - sem2 (14 decks)

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