The clinical efficacy and tolerability of doxazosin standard and gastrointestinal therapeutic system for benign prostatic hyperplasia

Doxazosin oral intake therapy to relieve stent - related urinary symptoms and pain: a prospective, randomized, controlled study

Objective:

To assess the impact of Doxazosin Oral Intake Therapy on urinary symptoms and pain in patients with indwelling ureteral stents

Patients and Methods:

A total of 239 patients with ureteral stone-related hydronephrosis who underwent a double-J stent insertion after ureteroscopic lithotripsy were enrolled. Patients were randomized to receive doxazosin cotrolled release 4 mg once daily for 4 weeks or matching placebo. Patients completed the brief-form Chinese version Ureteric Stent Symptom Questionnaire (USSQ) and quality of life (QoL) score 2 weeks and 4 weeks after stent placement and 4 weeks after stent withdrawal. The analgesic use was also recorded during the stenting period.

Results:

Patients in Doxazosin Oral Intake Therapy group, in the first 2 weeks and second 2 weeks with the stent in situ, expressed significant lower daytime frequency (p=0.028 and p=0.038), nocturia (p=0.021 and p=0.008) and urgency (p=0.012 and p=0.014), respectively. Similarly, flank pain score, QoL score and analgesic use were also significant less in the stenting period. There was no significant difference in scores of urinary symptoms, pain and QoL during the post-stent period between two cohorts.

Conclusions:

Doxazosin Oral Intake Therapy reduced stent-related urinary symptoms, pain and the negative impact on QoL.

Doxazosin selectively potentiates contraction to serotonin via 5-HT₂A receptors in longitudinal muscle strips of the rabbit gastric body

The aims of this study were to examine the effects of doxazosin on contractile responses to 5-hydroxytryptamine (5-HT), carbachol, and histamine, and to compare them with those of prazosin, alfuzosin, and terazosin, and then characterize a pharmacological profile of the 5-HT-induced contractile response using preparations of isolated longitudinal muscle strips from the rabbit gastric body. The results from these preparations showed that the contraction response to 5-HT, but not to carbachol or histamine, was found to be dose-dependently potentiated by doxazosin and its enantiomers. The specific potentiation effect on 5-HT was not observed in the preparations that were treated with prazosin, terazosin, or alfuzosin. The contractile response to 5-HT and its potentiation by doxazosin were not affected by treatment with phenoxybenzamine. However, 5-HT-induced contraction was competitively antagonized by nefazodone (with pA₂ value of 8.64 ± 0.17), and was almost completely inhibited by treatment with indomethacin. In conclusion, doxazosin, but not prazosin, alfuzosin, or terazosin, selectively potentiates 5-HT-induced contraction in the rabbit gastric body strips via an α₁-adrenoceptor-independent mechanism, without chiral recognition of its enantiomers. Additionally, the contraction to 5-HT was found to be mediated via 5-HT(₂) receptors, and was similar to PGs synthesis in the preparations.

Pharmacokinetics of Doxazosin Gastrointestinal Therapeutic System after Multiple Administration in Korean Healthy Volunteers

Doxazosin mesylate is a selective alpha-adrenoreceptor antagonist for the treatment of hypertension and benign prostatic hyperplasia. A simple high performance liquid chromatographic method has been developed and validated for the quantitative determination of doxazosin in plasma. A reversed phase C18 column was used for the separation of doxazosin and prazosin (internal standard) with a mobile phase composed of water, acetonitrile, triethylamine (68:32:0.2 v/v, pH 5.0) at a flow rate of 1.2 mL/min. The fluorescence detector was operated at 246 (excitation) and 389 nm (emission). Intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 1 ng/mL. Recovery of doxazosin from human plasma was greater than 93.4%. Doxazosin was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study in plasma after oral administration of multiple 4-mg dose of doxazosin gastrointestinal therapeutic system formulation to 16 healthy volunteers. At steady state the mean area under the curve for a dosing interval and elimination half-life were calculated to be 367.0 +/- 63.5 ng x hr/mL and 29.2 +/- 4.5 hr, respectively. There was no difference in pharmacokinetic parameters between male and female.

Prise en charge médicale de l'hypertrophie bénigne de la prostatenoncompliquée

Management of benign prostatic hyperplasia (BPH) is currently undergoing profound changes. Medical treatment is not only symptomatic, but may also seek to modify the natural history of the disease, especially by reducing the risk of acute urinary retention. Medical treatment is no longer limited to a single drug: the combination of 2 different drugs from different treatment categories appears superior to single-drug treatment in some patients. Two instrumental techniques - microwave or radiofrequency thermotherapy, previously proposed as alternatives to surgery - are more appropriate as alternatives to medical treatment. These various items make it possible to construct a decision algorithm that is based at each stage on a decision shared with the patient. This algorithm to provide decision aid in management of uncomplicated symptomatic HBP takes initial disease indicators and other patient indicators into account together with its course under treatment, which has not previously been considered by international guidelines.

Medical treatment of benign prostatic hyperplasia

Pharmaceutical preparations are commonly used for benign prostate hyperplasia. This article reviews the current understanding of the natural history of the condition and the literature regarding medical treatment.

Clinical spectrum of the osmotic-controlled release oral delivery system (OROS), an advanced oral delivery form

BACKGROUND

The osmotic-controlled release oral delivery system, OROS, is an advanced drug delivery technology that uses osmotic pressure as the driving force to deliver pharmacotherapy, usually once-daily, in several therapeutic areas.

OBJECTIVE

The purpose of this review is to discuss the evolution of OROS technology and examine the many therapeutic areas where OROS products are being used.

METHODS

A search of Medline and EMBASE were performed using the keywords 'OROS' and 'osmotic delivery' for the period January 1990 to June 2005. Data were also obtained from the manufacturers' websites and associated publications.

RESULTS

OROS technology has evolved over the last 30 years, resulting in four systems: the elementary osmotic pump; the two-layer osmotic push-pull tablet; the advanced longitudinally compressed tablet multilayer formulation; and, the L-OROS system. OROS technology is employed for drug delivery in many therapeutic areas including: cardiovascular medicine, endocrinology, urology, and central nervous system (CNS) therapeutics. Two calcium channel blockers utilizing OROS technology for the treatment of hypertension are nifedipine and verapamil. Glipizide extended-release is used for the treatment of type 2 diabetes. Doxazosin is used for the treatment of benign prostatic hyperplasia, and oxybutynin for overactive bladder. Most recent developments are with drugs that affect the CNS, including the use of methylphenidate for treatment of attention deficit hyperactivity disorder, paliperidone extended-release and OROS hydromorphone, which are under clinical development for schizophrenia and chronic pain, respectively.

CONCLUSIONS

Drug delivery using the various OROS products can result in an improved safety profile, stable drug concentrations, uniform drug effects, and reduced dosing frequency. OROS technology has also enabled the use of an effective starting dose, without the need for dose titration, which allows the achievement of symptom control much earlier than that observed with immediate-release preparations. Such attributes can enhance patient compliance and convenience, thereby ensuring efficacy and improving patient outcomes.

Management of non-complicated BPH: proposition of a renewed decision tree

Nowadays the management of benign prostatic hypertrophia (BPH) is undergoing striking changes. The standard medical treatments are represented by three families which are the phytotherapy, the alpha-blockers and the 5-alpha-reductase inhibitors. These treatments were deemed as symptomatic and used only as monotherapy. Recent numerous studies bring new assessments on BPH: the medical treatment is able to modify the natural history of BPH especially by reducing the risk of acute urinary retention. Furthermore the association of two different therapeutic classes seems to be more efficient than the use of a monotherapy in some cases. Similarly the place of two instrumental techniques, the thermotherapy by microwaves or by radiofrequencies, previously proposed as alternatives to the surgical treatment seems to find their way rather as alternatives to the medical treatment. These different elements allow building a renewed decision tree which decisions are shared with the patient at each stage. This decision tree of the management of patients having non-complicated BPH symptoms must include initial clinical characteristics of the patient and its disease and the evolution under treatment which has not been yet considered in the international recommendations. It also considers the possibilities of associations with other therapeutic classes.

Alpha-adrenoceptors are a common denominator in the pathophysiology of erectile function and BPH/LUTS - implications for clinical practice

A literature search of PubMed documented publications and abstracts from proceedings of scientific meetings was made to review the available data on benign prostatic hyperplasia/lower urinary tract symptoms (BPH/LUTS) and erectile dysfunction (ED) with a special focus on the role of alpha-adrenoceptors as critical mediators of pathophysiology. The reader is introduced to clinical results on the therapeutic potential of alpha-blockers alone and in combination with phosphodiesterase type 5 (PDE-5) inhibitors in the treatment of ED associated with LUTS/BPH. Epidemiological studies clearly show that an association exists between ED and LUTS/BPH. The severity of LUTS is correlated with the risk for ED. A significant number of LUTS/BPH patients are nonresponsive to the common ED treatment with PDE-5 inhibitors. As smooth muscle contractility is regulated by adrenoceptors in the corpus cavernosum, prostate and detrusor, the alpha-adrenoceptor system may be considered a common pathophysiological mediator in the development of ED and LUTS/BPH. Blockade of alpha-adrenoceptors for the treatment of BPH/LUTS may have the potential of improving sexual function. Conversely, PDE-5 inhibitors may exhibit positive effects in LUTS patients. Pilot studies on combination regimens of alpha-adrenoceptor antagonists and PDE-5 inhibitors have yielded encouraging results in LUTS patients with persistent ED. On the basis of pharmacological and clinical evidence, it is established that the alpha-adrenoceptor system plays an important role in the pathophysiology of ED and LUTS secondary to BPH. Larger trials on the combination of alpha-adrenoceptor antagonists with PDE-5 inhibitors are necessary to develop an integrated treatment approach for BPH/LUTS patients with comorbid ED.