「基礎醫學-藥理學」藥理學基礎(Fundamentals of Pharmacology)

藥物作用機制

類固醇和非類固醇抗發炎藥
Corticosteroids and Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)


前列腺素是一群具有多種生理作用的脂質化合物。它們參與了身體許多重要的生理過程,包括:
發炎反應: 前列腺素會引起血管擴張、增加血管通透性,並刺激神經末梢,導致紅腫、發熱、疼痛等發炎反應。
疼痛: 前列腺素會降低痛覺閾值,增加對疼痛的敏感性。
發燒: 前列腺素會重置體溫調節中樞,導致體溫升高。
胃黏膜保護: 前列腺素能刺激胃黏液的分泌,保護胃黏膜不受胃酸侵蝕。
血小板凝集: 前列腺素參與血小板的凝集,有助於止血。
平滑肌收縮: 前列腺素能引起子宮、腸道等平滑肌的收縮。

非類固醇抗發炎藥物(NSAIDs)可以抑制環氧合酶(cyclooxygenase)的活性,減少前列腺素(prostaglandin)生成,而產生解熱、鎮痛,以及抗發炎效果。
Nonsteroidal anti-inflammatory drugs (NSAIDs) can inhibit the activity of cyclooxygenase (COX), reducing the production of prostaglandins, which leads to antipyretic, analgesic, and anti-inflammatory effects.

misoprostol為前列腺素致效劑(agonist),是一種前列腺素E1的合成類似物,可降低胃酸釋出,也能促進胃黏液的產生,增加黏膜的屏障功能,以緩解胃潰瘍的病症,同時促進腸道平滑肌的收縮,增加腸道蠕動。

NSAIDs與misoprostol對前列腺素的作用方向相反: NSAIDs抑制前列腺素的生成,而misoprostol則模擬前列腺素的作用。

類固醇抗發炎藥可以有效抑制發炎反應,但可能會延緩傷口癒合並增加感染風險。
Corticosteroid anti-inflammatory drugs can effectively suppress inflammatory response, but may delay wound healing and increase the risk of infection.

Irbesartan可以拮抗第一型 angiotensin II(AT1)受體,使小動脈及靜脈舒張,達到降血壓的效果,另外Captopril、Felodipine 和 Aliskiren 分別是血管張力素轉化酶抑制劑(ACE inhibitors)、鈣離子通道阻斷劑(CCBs)和血管張力素受體拮抗劑(ARBs)。

angiotensin converting enzyme(ACE)是一種參與血壓調節的酵素,ACE inhibitors 的作用機制是抑制血管張力素轉化酶(ACE),阻斷血管張力素 I 轉化為血管張力素 II。血管張力素 II 是一種強力的血管收縮劑,因此 ACE inhibitors 可以使血管擴張,降低血壓。

CCBs 的作用機制是阻斷鈣離子進入血管平滑肌細胞,使血管平滑肌鬆弛,血管擴張。

ARBs 的作用機制是直接阻斷血管張力素 II 與第一型 angiotensin II(AT1)受體的結合。AT1 受體是血管收縮的重要受體,因此 ARBs 可以使血管擴張,降低血壓。

另外的酵素功用如下:
HMG CoA reductase 是一種參與膽固醇合成的酵素。
xanthine oxidase 是一種參與尿酸合成的酵素。
Other enzymes and their functions are as follows:
Angiotensin converting enzyme (ACE) is an enzyme involved in blood pressure regulation.
HMG CoA reductase is an enzyme involved in cholesterol synthesis.
Xanthine oxidase is an enzyme involved in uric acid synthesis.

心臟相關藥物

Milrinone具有強心及擴張血管之功能,長期使用會引發心律不整,此藥物的藥理作用機制為第三型磷酸雙酯酶(phosphodiesterase 3,PDE3)抑制劑,PDE3 是一種在心臟、血管和平滑肌中含量豐富的酶,可以催化cAMP 的水解,cAMP可調節心肌收縮、血管舒張和平滑肌鬆弛的功能,進而改善心臟功能且降低血壓,但由於同時也增加心肌細胞的自動性、延長心肌細胞的動作電位持續時間、減慢心傳導速度,最後可能會導致心律不整。
Milrinone has positive inotropic and vasodilatory effects. Long-term use can lead to arrhythmias. The pharmacological mechanism of this drug is that it is a phosphodiesterase 3 (PDE3) inhibitor. PDE3 is an enzyme that is abundant in the heart, blood vessels, and smooth muscle. It can catalyze the hydrolysis of cAMP, cAMP can regulate myocardial contraction, vascular dilation, and smooth muscle relaxation, thereby improving cardiac function and lowering blood pressure. However, it can also increase the automaticity of cardiac cells, prolong the duration of the cardiac action potential, and slow down the conduction velocity, which may eventually lead to arrhythmias.

預防和治療血栓

Warfarin是一種口服抗凝血藥物,用於治療和預防血栓形成,應在醫生指導下服用。患者不可自行停用藥物,以免增加血栓形成的風險。
Warfarin is an oral anticoagulant medication used to treat and prevent blood clots. It should be taken under the guidance of a healthcare provider. Patients should not discontinue the medication without consulting their doctor, as this may increase the risk of blood clot formation.
它通過抑制維生素K的作用,阻礙凝血因子的合成,從而降低血液的凝固能力。
Warfarin exerts its anticoagulant effect by inhibiting the action of vitamin K, thereby interfering with the synthesis of clotting factors. This, in turn, reduces the blood's clotting ability.
因此,Warfarin的藥效應通過檢測國際標準化比值(INR)來監測,而非活化部分凝血酶原時間APTT。
The effectiveness of Warfarin therapy is assessed by monitoring the international normalized ratio (INR), rather than the activated partial thromboplastin time (APTT). The INR is a standardized measure of blood clotting time that takes into account the differences in sensitivity among various coagulation tests.

深綠色蔬菜,如菠菜、甘藍菜、芥菜等,富含維生素K。維生素K是凝血因子的重要輔酶,可促進凝血因子的合成。
Dark green vegetables, such as spinach, kale, and mustard greens, are rich sources of vitamin K. Vitamin K is an essential cofactor for clotting factors and promotes their synthesis.
因此,服用Warfarin的患者應避免大量食用深綠色蔬菜,且維生素K攝入量應保持一致,以免影響藥效。
Therefore, patients taking Warfarin should avoid consuming large quantities of dark green vegetables. Additionally, they should maintain a consistent intake of vitamin K to prevent fluctuations that could impact the medication's effectiveness.

口服抗凝血劑warfarin中毒出血時,應給予肌肉注射或靜脈注射維生素K,Warfarin是一種抗凝血劑,其作用機轉是通過抑制維生素K環氧化物還原酶,從而阻礙維生素K的再生。
In cases of bleeding due to oral anticoagulant warfarin poisoning, vitamin K should be given by intramuscular or intravenous injection. Warfarin is an anticoagulant that works by inhibiting vitamin K epoxide reductase, thereby blocking the regeneration of vitamin K.

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