Management of urinary retention due to benign prostatic hyperplasia using luteinizing hormone-releasing hormone agonist

Advances in the development of hormonal modulators for the treatment of benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a leading disorder of the ageing male population and is characterized by a progressive enlargement of the prostate, resulting in the obstruction of the proximal urethra and hence the disturbance in normal urinary flow and further quality of life of the patients. Therefore, there is an imperative need to develop a therapeutic modality to combat the overgrowth of the prostate with improvements in both the urinary flow rate and the quality of life of the patients. At present, alpha-blockers, which act on the dynamic component of the disease to regulate the increased adrenergic tone of the lower urinary tract smooth muscles, and 5-alpha-reductase inhibitors, which control the overgrowth of the prostate and hence static component by regulating the levels of androgens, are the mainstay of therapies for the treatment of BPH and associated lower urinary tract symptoms. However, each target class has its own limitations in terms of compromised efficacy or tolerability. Therefore, it is pertinent to have an effective and safe therapeutic modality for the further improvement of life of the geriatric male population. Hormone modulators, which regulate the overgrowth of the prostate, represent one of the important categories that have been explored and that is still undergoing certain investigations towards the development of a therapeutic entity for the treatment of BPH. The key lies in achieving the differentiation in terms of improved tolerability with comparable or better efficacy over the existing class of drugs. Gonadotropin receptor modulators and vitamin D receptor agonists may represent promising druggable targets in this therapeutic area, due to the availability of proof of principles and concepts in preclinical animal models and human subjects.

Benign prostatic hyperplasia: an insight into current investigational medical therapies

Benign prostatic hyperplasia (BPH) is a leading disorder of the elderly male population that is characterised by a progressive enlargement of prostatic tissue, resulting in obstruction of the proximal urethra and causing urinary flow disturbances. The pathophysiology of BPH associated with lower urinary tract symptoms is characterised by increased adrenergic tone (dynamic component) leading to smooth muscle contraction and prostatic overgrowth due to androgenic stimulation (static component); therefore, the therapeutic armamentarium of BPH can be broadly divided into antiadrenergic and antiandrogenic approaches. alpha1-Adrenoceptor antagonists and 5alpha-reductase inhibitors are well-established representatives of the two categories, respectively. Other antiandrogenic approaches involve gonadotropin-releasing hormone agonists and antagonists for the treatment of prostate hyperplasia. Apart from these approaches, new approaches with novel targets are emerging. The advent of new therapies is, however, more oriented towards the static component. These involve metabolic factors (hexokinase inhibitor), growth factors (vitamin D3 analogues), oxytocin antagonists and gonadotropin-releasing hormone Gi agonist-based therapies. Gene therapy and photodynamic therapies are other emerging therapies for relieving symptoms in BPH patients. With the initial success of upcoming targets, the unmet need to develop an efficacious and relatively safe therapeutic modality is discussed. Nevertheless, their long-term safety and efficacy needs to be evaluated in large-scale clinical trials. The future also belongs to combination therapies to combat both dynamic and static disease components and for extended indications such as micturition disorder and non-bacterial prostatitis.

Natural potent androgens: lessons from human genetic models

Male pseudohermaphroditism due to 17 beta-hydroxysteroid dehydrogenase-3 (17 beta-HSD-3) deficiency and 5 alpha-reductase-2 (5 alpha-RD-2) deficiency provides natural human genetic models to elucidate androgen actions. To date, five 17 beta-HSD isozymes have been cloned that catalyse the oxidoreduction of androstenedione and testosterone and dihydrotestosterone (DHT), oestrone and oestradiol. Mutations in the isozyme 17 beta-HSD-3 gene are responsible for male pseudohermaphroditism due to 17 beta-HSD deficiency. The type 3 isozyme preferentially catalyses the reduction of androstenedione to testosterone and is primarily expressed in the testes. Fourteen mutations in the 17 beta-HSD-3 gene have been identified from different ethnic groups. Affected males with the 17 beta-HSD-3 gene defect have normal wolffian structures but ambiguous external genitalia at birth. Many are raised as girls but virilize at the time of puberty and adopt a male gender role. Some develop gynaecomastia at puberty, which appears to be related to the testosterone/oestradiol ratio. Two 5 alpha-reductase (5 alpha-RD) isozymes, types 1 and 2, have been identified, which convert testosterone to the more potent androgen DHT. Mutations in the 5 alpha-RD-2 gene cause male pseudohermaphroditism, and 31 mutations in the 5 alpha-RD-2 gene have been reported from various ethnic groups. Such individuals also have normal wolffian structure but ambiguous external genitalia at birth and are raised as girls. Virilization occurs at puberty, often with a gender role change. The prostate remains infantile and facial hair is decreased. Balding has not been reported.

Pathogenesis and medical management of benign prostatic hyperplasia

Benign prostatic hyperplasia is an almost universal disorder of aging males. The disease is heterogeneous with respect to the histology, size, symptoms, and response to medical management. Current medical therapies are based upon the knowledge of the pathophysiology of the disease and include hormonal therapies and alpha(1)-adrenergic blockade. Although there are at present no prognostic indicators of response to therapy, future studies may help delineate those patients who will most benefit from the various forms of treatment.

Effetto terapeutico degli LH-RH analoghi nei pazienti con IPB inoperabili portatori di catetere a dimora: LH-RH analogs in patients with urinary retention due to BPH carrying an indwelling catheter

From March to December 1991, 10 patients with BPH and urinary retention, not elegible for surgery were treated with Leuprolide at the Department of Urology of B. Ramazzini Hospital in Carpi. The drug was administered subcutaneously or i.m. every 30 days for at least 12 months. The average number of injections was 5. All the patients could void spontaneously after 1-2 injections of the drug. The prostate volume was controlled by digital palpation and rectal ultrasound. A reduction in volume of 25% was observed after 3 months on transrectal ultrasound. PSA was determined and controlled in 5 patients only. All the patients had a decreased PSA value after administration of the drug. No important side effects were observed in the study. We believe that LH-RH injection is a useful therapy in patients with BPH and urinary retention, who are not candidates for surgery.

Safety, side effects and patient acceptance of the luteinizing hormone releasing hormone agonist leuprolide in treatment of benign prostatic hyperplasia

The luteinizing hormone releasing hormone agonist leuprolide was investigated in a double-blind, randomized, placebo-controlled study comprising 50 evaluable patients with moderate to severe symptoms resulting from benign prostatic hyperplasia. Patients received 3.75 mg. leuprolide depot or placebo as an injection every 28 days for 24 weeks. Hemoglobin level decreased by 0.8 gm/100 ml. (p = 0.0052) for patients receiving leuprolide. Mean testicular volume decreased by 28.9% (p < 0.001) compared to placebo. Of 26 patients receiving leuprolide 5 had a weight gain of more than 3 kg. Almost all patients receiving leuprolide experienced hot flushes. Breast changes, and loss of energy and vigor were not more pronounced than for patients receiving placebo. Erectile function and sexual activity were lost during treatment. Libido also decreased but was still partially retained. Despite this, patients receiving leuprolide were generally contented with their sexual life during treatment. Side effects were bothersome for some patients but were reversible. Of the patients in our study 73% expressed that they could repeat or continue treatment if that had been possible. The high cost of these drugs will limit their use for a benign condition, such as benign prostatic hyperplasia.

The influence of finasteride on the volume of the peripheral and periurethral zones of the prostate in men with benign prostatic hyperplasia

To determine the influence of androgen deprivation induced by the potent 5 alpha-reductase inhibitor finasteride on the volume of the zones of the prostate, 20 symptomatic men with established BPH were randomized to one of three groups: placebo, finasteride 1 mg, and finasteride 5 mg/day. The volume of the entire prostate gland, periurethral zone, and peripheral zone and the seminal vesicles were determined by three dimensional reconstructions of magnetic resonance contoured images of the prostate. There was no significant difference between the results achieved with 1 and 5 mg of finasteride per day; thus the results in these two groups were combined. In the placebo group there was no significant change in the volume of any structure. Following treatment for 1 year with finasteride there was a significant (P < 0.02) 17% decrease in total gland size (11.5 +/- 3.2 cc). Similarly, there was a significant (P < 0.02) 17% decrease in total gland size (11.5 +/- 3.2 cc). Similarly, there was a significant (P < 0.03) decrease in the size of the periurethral zone of the prostate (6.2 +/- 3 cc). Although there was also a decrease in the size of the peripheral zone of the prostate (2.8 +/- 1.2 cc) this did not reach statistical significance. There was no significant change in the volume of the seminal vesicles. These findings indicate for the first time that androgen deprivation induces a significant decrease in the size of the periurethral zone of the prostate in men with established BPH.

Treatment of benign prostatic hypertrophy by a long-acting gonadotropin-releasing hormone analogue: 1-year experience

Benign prostatic hypertrophy, a common ailment among elderly men, usually is treated by surgery. Since androgens enhance prostatic hypertrophy, their withdrawal seems a logical way to treat this condition. Recently gonadotropin-releasing hormone analogues, known to produce "chemical castration," have been tried in cases of benign prostatic hypertrophy. We report our experience with 20 men treated by a monthly injection of gonadotropin-releasing hormone for prolonged periods. In 17 men treated for 6 months the prostatic volume decreased to an average of 63% of the initial volume; however, this did not correlate with clinical objective improvement. Only 6 men attained normal flow rates. Residual urine volume remained unaltered. Ten patients experienced subjective amelioration, while only 7 (40%) reported objective and subjective improvement. Maximal decrease in prostatic volumes was reached at 9 months of treatment and further treatment did not cause additional shrinkage. At 3 months after discontinuation of treatment prostatic volumes returned to 95 +/- 10.5% of pre-treatment values. A similar decrease in flow rates also was noted. Symptoms remained improved for longer periods. We conclude that this mode of treatment offers little to the majority of men with benign prostatic hypertrophy. Proper patient selection, based perhaps on serum prostate specific antigen, might augment positive results. This therapy should be restricted to patients considered high risk for any surgical and anesthetic intervention, and then it will have to be continued indefinitely.