肾上腺素受体阻断药课件.pptVIP

Adrenoceptor Blocking Drugs 肾上腺素受体阻断药 I.classification α-Adrenoceptor Blocking Drugs --Nonselective α Receptor Blocker—Phentolamine（酚妥拉明）etc. --α1-R blocker—Prazosin（哌唑嗪） --α2-R blocker—Yohimbine（育亨宾）β-Receptor Blocking Drugs --Nonselectiveβ-R blocker– propranolol（普萘洛尔） --Selectiveβ-R blocker– atenolol（阿替洛尔）α and β-Receptor Blocking Drugs-- labetalol（拉贝洛尔） Phentolamine（酚妥拉明）A. Pharmacological effects 1.Reduces peripheral resistance -- block α1 2.Cardiac stimulation --reflex effect --blocks presynaptic（突触前的）α2→ enhanced NA release 3.Inhibits 5-HT 4.H1,H2 agonistB.Uses 1.Peripheral vascular diseases 2.Excess local vasoconstrictor 3.Shock α-Receptor Blocking Drugs 4.Myocardial（心肌的）infarction（梗死形成）and stubborn（顽固的）congestive heart failure 5. Pheochromocytoma（嗜铬细胞瘤）Tolazoline（妥拉唑啉） 1. Effects similar to phentolamine but less potent. 2.Cholinomimetic（拟胆碱样作用）effect and histamine like effects are stronger.A.Side effects postural hypotension（体位性低血压）, tachycardia (reflex), arrhythmia and angina（绞痛） B.Uses 1.Peripheral vasospastic（血管痉挛的）disease 2.Extravasation（溢出）of iv. NAPhenoxybenzamine（酚苄明，又名苯苄胺 dibenzyline）1.Binds to αreceptors producing irreversible（不可逆的） blockade (14-48h).2.Inhibits reuptake（再摄取）of NA 3.Blocks H1 and 5-HT receptors. A.Pharmacological actions 1.Antagonizes（对抗）α receptor 2.Blocks vasoconstriction but little fall in blood pressure 3.Cardiac output increased -- reflex effect -- blockade of presynaptic α2B.Uses 1.Peripheral vascular diseases 2.Shock 3.Pheochromocytoma（嗜铬细胞瘤） C. Side effects 1.Nasal stuffiness（鼻塞） 2.Fatigue（疲乏）, sedation（嗜睡）, nausea（恶心） 3.Tachycardia 4.Postural hypotensionPrazosin（哌唑嗪）1.Highly selective for α1 , low affinity for α2 2.Relaxation of both arterial and venous smooth muscle -- fall in blood pressure 3.Decreases preload and afterload of heart 4.Effective in the management of hypertensionYohimbine（育亨宾） --used as a tool