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Alfuzosin用於治療女性 case之討論

適應症

Alfuzosin Benign prostatic hyperplasia

Tamsulosin BPH所伴隨的排尿障礙

Terazosin Hypertension.BPH

Doxazosin Hypertension.BPH

Alfuzosin,tamsulosin,terazosin and doxazosin are antihypertensive agents with an affinity for postsynaptic α-1adrenergic reptors.Theseα-1 receptor antagonists relax the smooth muscle of human urethra.They have similar efficacy for the treatment of lower urinary tract symptoms suggestive of BPH.

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Machenism 1• Most men over age 50 experience enlargement of the

prostate gland(benign prostatic hyperplasia [BPH]),which is characterized by urinary hesitancy, incomplete bladder emptying,incontinence, or nocturia.

• The selective alpha-1 adrenergic blockers have been shown to significantly increase urinary flow rates and decrease outflow obstruction and irritation symptoms, such as frequency, nocturia, urgency, and urge incontinence, associated with BPH.

• Alfuzosin is a selective α-1 adrenoceptor antagonist. Alfuzosin bears structural similarity to prazosin, and both are quinazoline derivatives. In vitro and in vivo studies have demonstrated potent and selective α-1 adrenoceptor antagonistic effects of alfuzosin in the genitourinary tract(proximal urethral, bladder base, prostatic , and prostatic capsule smooth muscle).

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Machenism 2

• α-1 adrenergic receptor blockers may provide prompt relief of BPH symptoms,but don’t reduce prostate size. These drugs also have an antihypertensive effect.

• Terazosin and doxazosin, like other α-1 adrenergic blocking agents, can cause marked hypotension( especially postural hypotension) and syncope with sudden loss of consciousness with the first few doses.

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排尿障礙

• 以功能上來分類： (一 )儲存功能失調，如膀胱容積變小，逼尿肌不穩定，尿道括約肌鬆弛。

(二 )排空功能失調，如逼尿肌無力，前列腺肥大，尿道狹窄，括約肌痙攣。

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正常排尿功能• 排尿過程包括了尿液注入膀胱及排出兩階段。尿液自輸尿管慢慢注入膀胱時，交感神經使膀胱迫肌放鬆，但膀胱頸及括約肌收縮，因此膀胱可在低壓狀態容納更多尿液而又不會流出體外。當儲存尿量到一定程度，我們可感覺到尿意。在接近膀胱容積之上限時，膀胱內之壓力升高，尿意也增強，但成熟的膀胱括約肌可阻止尿液流出，直到在適合的地點 (如廁所 )，膀胱迫肌收縮，括約肌放縮，在短時間內排出絕大部分的尿液。

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Compare• Like tamsulosin, alfuzosin is more selective for α-1

adrenergic receptors in the lower urinary tract than other drugs in its class. Although alfuzosin is less selective than tamsulosin, both drugs have a less pronounced effect on blood pressure than the other α-blockers and neither is labeled to treat hypertension.

• Decreases in symptom scores seemed most favorable with terazosin treatment.

• Adverse effect profiles of alfuzosin SR and tamsulosin are superior to the side effect profiles of doxazosin and terazosin.

• Sustained-release alfuzosin compares favorably with other α-1 blockers(ie,tamsulosin,terazosin,doxazosin),both in symptom and flow rate improvement and adverse effect profile.

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Reference

• Micromedex

• Ovids

• 仿單• Drug fact