Magoha G A
Department of Surgery, College of Health Sciences, University of Nairobi.
East Afr Med J. 1996 Jul;73(7):453-6.
Benign prostatic hyperplasia (BPH) is a common disease affecting elderly men with 70% of men over 70 years showing microscopic evidence of hyperplasia. Transurethral resection of the prostate is the gold standard treatment. Medical management of BPH has involved the use of plant extracts, amino acids, kampo and animal organ preparations in various countries with unsatisfactory results. The use of alpha adrenergic antagonists dates back twenty years representing a major breakthrough in the treatment by relaxation of the dynamic contraction of smooth muscle component of prostatic obstruction. The evolution of alpha antagonist therapy resulted in clinical trials with selective antagonists such as prazosin, alfuzosin, indoramin, terazosin and doxazosin all of which achieve similar effective relief of obstructive symptoms as phenoxybenzamine, but with fewer side effects related to postural hypotension. 5-alpha reductase inhibitors, finasteride and episteride, recently synthesised act on the static component of obstruction caused by the enlarging prostate. They inhibit conversion of testosterone to the potent intracellular androgen dihydrotestosterone (DHT) resulting in the reduction of prostate volume and improvement of obstructive symptoms. Clinical trials with finasteride for three years indicate that 63% of patients had a reduction of greater than 20% in prostatic volume and 42% had a decrease of greater than 30% with a mean increase peak flow rate of 2.4 mls/s equivalent, to 20 years reversal of disease progression.
良性前列腺增生（BPH）是一种影响老年男性的常见疾病，70岁以上的男性中有70%有增生的微观证据。经尿道前列腺切除术是金标准治疗方法。在各个国家，BPH的药物治疗涉及使用植物提取物、氨基酸、汉方药物和动物器官制剂，但效果并不理想。α肾上腺素能拮抗剂的使用可以追溯到二十年前，它代表了通过放松前列腺梗阻平滑肌成分的动态收缩来进行治疗的一项重大突破。α拮抗剂疗法的发展导致了对选择性拮抗剂的临床试验，如哌唑嗪、阿夫唑嗪、吲哚拉明、特拉唑嗪和多沙唑嗪，所有这些药物在缓解梗阻症状方面都与苯氧苄胺有相似的效果，但与体位性低血压相关的副作用较少。5-α还原酶抑制剂非那雄胺和依立雄胺是最近合成的，作用于前列腺增大引起的梗阻的静态成分。它们抑制睾酮转化为强效的细胞内雄激素双氢睾酮（DHT），从而导致前列腺体积减小和梗阻症状改善。非那雄胺三年的临床试验表明，63%的患者前列腺体积减少超过20%，42%的患者减少超过30%，平均最大尿流率增加2.4毫升/秒，相当于疾病进展逆转20年。
