Immunostimulation in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS): a one-year prospective, double-blind, placebo-controlled study

Clinical Efficacy Analysis of Biofeedback Electrical Stimulation Combined with Doxycycline in the Treatment of Type IIIA Chronic Prostatitis

Purpose

To analyse the clinical efficacy of biofeedback electrical stimulation combined with doxycycline in the treatment of type IIIA chronic prostatitis.

Methods

Eighty patients who met the diagnostic criteria of type IIIA chronic prostatitis in our hospital between February 2020 and February 2022 were selected and equally divided into the drug group and electrical stimulation group according to the random number table method. The drug group was treated with medication alone for 4 weeks; the electrostimulation group was treated with biofeedback electrostimulation on top of medication for 12 weeks. The expressed prostatic secretious (EPS) routine (lecithin bodies, white blood cells) and the maximum urinary flow rate (Q_max) and mean urinary flow rate (Q_ave) were measured before and after treatment in both groups, and the National Institutes of Health chronic prostatitis symptom index (NIH-CPSI) was used to score the urinary symptom, pain or discomfort, and quality of life and determine the efficacy of the treatment in both groups.

Results

After treatment, the number of lecithin bodies and white blood cells in EPS improved significantly in both groups compared to before, and both the electrical stimulation group was better than the drug group (P < 0.05). After treatment, the Q_max and Q_ave were significantly higher in both groups than before, and both the electrical stimulation groups were higher than the drug group (P < 0.05). After treatment, the urinary symptom scores, pain or discomfort scores, quality of life scores, and total NIH-CPSI scores were significantly lower in both groups than before, and all were lower in the electrical stimulation group than in the drug group (P < 0.05). After treatment, the overall efficiency of patients in the electrical stimulation group was significantly higher than that of the drug group (P < 0.05).

Conclusion

Biofeedback electrical stimulation combined with doxycycline in the treatment of type IIIA chronic prostatitis can synergistically improve the patient's inflammation level, urinary dysfunction, relieve pelvic floor tension myalgia, and improve their quality of life, opening up new avenues for the rehabilitation of patients with type IIIA chronic prostatitis.

A systematic review and meta-analysis of placebo effect in clinical trials on chronic prostatitis/chronic pelvic pain syndrome

BACKGROUND

It is a common practice to control efficacy of pharmacological treatment with a placebo group. However, placebo itself may affect subjective and even objective results. The purpose of this study was to evaluate the placebo effect on symptoms of CP/CPPS to improve future clinical trials.

METHODS

A search at three databases (Scopus, MEDLINE, and Web of Science) was conducted to identify double-blind placebo-controlled clinical trials on the treatment of CP/CPPS published until April 2021. The primary outcome - National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) score.

SECONDARY OUTCOMES

Qmax, PVR, IPSS, and prostate volume.

RESULTS

A total of 3502 studies were identified. Placebo arms of 42 articles (5512 patients, median 31 patients) were included in the systematic review. Systematic review identified positive changes in the primary endpoint, meta-analysis of 10 articles found that NIH-CPSI total score results were significantly influenced by placebo, mean difference -4.2 (95% confidence interval [CI]: -6.31, -2.09). Mean difference of NIH-CPSI pain domain was -2.31 (95% CI: -3.4, -1.21), urinary domain -1.12 (95% CI: -1.62, -0.62), quality of life domain -1.67 (95% CI: -2.38, -0.96); p < 0.001 for all. In case of the objective indicator - Qmax, there were three articles included in the meta-analysis. Qmax mean change from baseline was 0.68 (95% CI: -0.85, 2.22, p = 0.38). Systematic review showed no significant changes in pain, measured by VAS or other scores, IPSS and PVR.

CONCLUSIONS

Placebo significantly affected the subjective parameters (NIH-CPSI) and limitedly affected various other measurements of pain (visual analog scale, McGill pain questionnaire). There was no long-term effect on IPSS and objective measurements (Qmax, PVR). This study can be used in further clinical trials to develop general rules of CPPS treatment assessment.

Therapeutic interventions to urologic chronic pelvic pain syndrome and UPOINT system for clinical phenotyping: How far are we?

The assessment and management of urologic chronic pelvic pain syndrome (UCPPS), is controversial. It is classified by voiding symptoms, pelvic pain, and bladder pain, which is weekly treated, weekly understood, and bothersome. In the aspect of clinical efforts and research to help people with this syndrome have been hampered by the deficiency of a widely reliable, accepted, and a valuable tool to evaluate the patient symptoms and quality of life (QoL) impact. However, the etiology comes into sight is multifactorial, and available treatment options have been imprecise considerably in present years. We compiled the published literature on the assessment of the syndrome, a tentative role of pharmacological and non-pharmacological (conservative, alternative, and invasive therapy) interventions in eradicating the disease as well as improving symptoms. The previously published literature on animal models has established the association of immune systems in the etiology, pathogenesis, and progression of the disease. The UPOINT system for clinical phenotyping of UCPPS patients has six predefined domains that direct multimodal therapy, which would lead to significant symptom improvement in the medical field. The narrative review aims to scrutinize the fluctuating scientist's views on the evaluation of patient and multimodal treatment of the UPOINT system.

Contemporary Management of Chronic Prostatitis

Chronic prostatitis (CP) is a common condition, yet remains a challenge to treat in clinical practice due to the heterogeneity of symptoms. The aim of this article is to undertake a narrative review using key research papers in this field in order to develop a treatment algorithm and research recommendations for the management of type II and type III prostatitis taking a broader look at interventions beyond those recommended in the European Association of Urology Guidelines. A search was performed using multiple databases and trial registries with no language restrictions. Searches were completed on March 1, 2021, with a focus on randomized controlled trials (RCTs), meta-analyses, and systematic reviews. However, in areas with a dearth of such studies, we included case series and observational studies, thus allowing us to assess current levels of evidence and areas of potential research. We identified and reviewed 63 studies. The level of evidence and the quality of trials were assessed and reported. Research recommendations, where applicable, were also highlighted. CP/chronic pelvic pain syndrome (CPPS) is a heterogenous term referring to diverse symptomology that requires tailored treatments depending on the patients' complaints. After a review of the evidence available, we present a treatment algorithm that is based on the much-discussed UPOINT (urinary symptoms, psychosocial dysfunction, organ-specific findings, infection, neurologic/systemic, and tenderness of muscles) framework. Future studies should focus on multimodal therapy based on such frameworks and provide the future direction of this complex condition.

Diagnostic and Management Strategies for Patients with Chronic Prostatitis and Chronic Pelvic Pain Syndrome

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common and often heterogenous condition that can have severe consequences on patient quality of life. In this review, we describe the pathophysiology, diagnostic work-up, and treatment of patients with CP/CPPS incorporating the most recent literature. Studies have demonstrated that CP/CPPS involves a complex pathophysiology, including infectious, immunologic, neurologic, endocrinologic, and psychologic etiologies, with frequent intersections between the different entities. Despite robust research assessing a variety of therapeutics targeting these etiologies, clinical trials have failed to identify an empiric treatment strategy applicable specifically to older adult male patients with CP/CPPS. As such, it can be challenging to manage older male patients with this condition. The advent of clinical phenotyping of patients with CP/CPPS has led to advances in tailored management strategies. Monomodal therapy has been largely unsuccessful because of the unclear and complex etiology of CPPS. As a result, CP/CPPS therapy has transitioned to a multimodal approach, including both pharmacologic and non-pharmacologic therapies. The best studied pharmacologic therapies include antibiotics, alpha-blockers, anti-inflammatory and immunomodulatory agents, phytotherapies, phosphodiesterase inhibitors, hormonal agents, neuromodulatory agents, and antidepressants. The best studied non-pharmacological therapies include pelvic floor physical therapy, myofascial trigger point release, acupuncture and electroacupuncture, psychological support and biofeedback, and electrocorporeal shockwave therapy and local thermotherapy.

Antibiotic therapy effectiveness as an outcome predictor of complex treatment in chronic prostatitis/chronic pelvic pain syndrome

Introduction

We hypothesized that the history of antibiotic efficacy was related to the outcome of the treatment of patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and evaluated this as a phenotyping factor for such patients.

Material and methods

This prospective study included 74 patients with CP/CPPS aged 18–45 years old, who had at least 10 points on the National Institutes of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) scale and did not receive treatment for CP/CPPS for the last 3 months. There were 5 visits. Group 1 (n = 37) included patients with past successful antibiotic therapy. Group 2 (n = 37) included patients without antibiotic effect. All patients orally received: diclofenac sodium (100 mg/day, 2 weeks), modified release tamsulosin (0.4 mg/day, 1 month), and alcohol extract of Serenoa repens (320 mg/day, 6 months). Patients were monitored for symptoms of chronic prostatitis, depression, anxiety, and correlates of inflammation.

Results

After the treatment, NIH-CPSI scores significantly decreased (6 points or more) in Groups 1 and 2. The depression and anxiety symptoms significantly decreased only in Group 2. In Group 1, the efficacy of treatment was in 59.5% and 51.4% of patients, and in Group 2 – 83.8% and 78.4% at visits V2 and V4, respectively. The efficacy was significantly (p <0.05) lower in Group 1. The history of antibiotic efficacy and the outcome of this study treatment were significantly related (p <0.05).

Conclusions

For CP/CPPS, the history of antibiotic efficacy determines the prognosis of current treatment. The latent bacterial factor is assumed in 24.3–27% of cases of CP/CPPS.

Pharmacological interventions for treating chronic prostatitis/chronic pelvic pain syndrome

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common disorder in which the two main clinical features are pelvic pain and lower urinary tract symptoms. There are currently many approaches for its management, using both pharmacological and non-pharmacological interventions. The National Institute of Health - Chronic Prostatitis Symptom Index (NIH-CPSI) score is a validated measure commonly used to measure CP/CPPS symptoms. We considered a 25% decrease of NIH-CPSI baseline score or a six-point reduction as MCID.

OBJECTIVES

To assess the effects of pharmacological therapies for chronic prostatitis/chronic pelvic pain syndrome.

SEARCH METHODS

We performed a comprehensive search using CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, trial registries, grey literature and conference proceedings, with no restrictions on the language of publication or publication status. The date of the latest search of all databases was July 2019.

SELECTION CRITERIA

We included randomised controlled trials. Inclusion criteria were men with a diagnosis of CP/CPPS. We included all available pharmacological interventions compared to placebo or in head-to-head comparisons.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, and assessed the risks of bias of included studies. We assessed the quality of the evidence (QoE) using the GRADE approach.

MAIN RESULTS

We included 99 unique studies in 9119 men with CP/CPPS, with assessments of 16 types of pharmacological interventions. Unless stated otherwise, our comparisons were based on short-term follow-up (less than 12 months). Most studies did not specify their funding sources; 21 studies reported funding from pharmaceutical companies.1. Alpha blockers: (24 studies, 2061 participants). We are uncertain about the effects of these drugs on prostatitis symptoms when compared to placebo at short-term follow-up (mean difference (MD) in total NIH-CPSI score -5.01, 95% confidence interval (CI) -7.41 to -2.61; 18 studies, 1524 participants, very low QoE) and at long-term follow-up (MD -5.60, 95% CI -10.89 to -0.32; 4 studies, 235 participants, very low QoE). Alpha blockers may be associated with an increased incidence of adverse events, such as dizziness and postural hypotension (risk ratio (RR) 1.60, 95% CI 1.09 to 2.34; 19 studies, 1588 participants; low QoE). Alpha blockers probably result in little to no difference in sexual dysfunction, quality of life and anxiety and depression (moderate to low QoE).2. 5-alpha reductase inhibitors (5-ARI): (2 studies, 177 participants). Finasteride probably reduces prostatitis symptoms compared to placebo (NIH-CPSI score MD -4.60, 95% CI -5.43 to -3.77; 1 study, 64 participants; moderate QoE) and may not be associated with an increased incidence of adverse events (low QoE). There was no information on sexual dysfunction, quality of life or anxiety and depression.3. Antibiotics: (6 studies, 693 participants). Antibiotics (quinolones) may reduce prostatitis symptoms compared to placebo (NIH-CPSI score MD -2.43, 95% CI -4.72 to -0.15; 5 studies, 372 participants; low QoE) and are probably not associated with an increased incidence in adverse events (moderate QoE). Antibiotics probably result in little to no difference in sexual dysfunction and quality of life (moderate QoE). There was no information on anxiety or depression.4. Anti-inflammatories: (7 studies, 585 participants). Anti-inflammatories may reduce prostatitis symptoms compared to placebo (NIH-CPSI scores MD -2.50, 95% CI -3.74 to -1.26; 7 studies, 585 participants; low QoE) and may not be associated with an increased incidence in adverse events (low QoE). There was no information on sexual dysfunction, quality of life or anxiety and depression.5. Phytotherapy: (7 studies, 551 participants). Phytotherapy may reduce prostatitis symptoms compared to placebo (NIH-CPSI scores MD -5.02, 95% CI -6.81 to -3.23; 5 studies, 320 participants; low QoE) and may not be associated with an increased incidence in adverse events (low QoE). Phytotherapy may not improve sexual dysfunction (low QoE). There was no information on quality of life or anxiety and depression.6. Botulinum toxin A (BTA): Intraprostatic BTA injection (1 study, 60 participants) may cause a large reduction in prostatitis symptom (NIH-CPSI scores MD -25.80, 95% CI -30.15 to -21.45), whereas pelvic floor muscle BTA injection (1 study, 29 participants) may not reduce prostatitis symptoms (low QoE). Both comparisons used a placebo injection. These interventions may not be associated with an increased incidence in adverse events (low QoE). There was no information on sexual dysfunction, quality of life or anxiety and depression.7. Allopurinol: (2 studies, 110 participants). Allopurinol may result in little to no difference in prostatitis symptoms and adverse events when compared to placebo (low QoE). There was no information on sexual dysfunction, quality of life or anxiety and depression.8. Traditional Chinese medicine (TCM): (7 studies, 835 participants); TCM may reduce prostatitis symptoms (NIH-CPSI score, MD -3.13, 95% CI -4.99 to -1.28; low QoE) and may not be associated with an increased incidence in adverse events (low QoE). TCM probably does not improve sexual dysfunction (moderate QoE) and may not improve symptoms of anxiety and depression (low QoE). There was no information on quality of life.The most frequent reasons for downgrading the QoE were study limitations, inconsistency and imprecision. We found few trials with active comparators.

AUTHORS' CONCLUSIONS

We found low- to very low-quality evidence that alpha blockers, antibiotics, 5-ARI, anti-inflammatories, phytotherapy, intraprostatic BTA injection, and traditional Chinese medicine may cause a reduction in prostatitis symptoms without an increased incidence of adverse events in the short term, except for alpha blockers which may be associated with an increase in mild adverse events. We found few trials with active comparators and little evidence of the effects of these drugs on sexual dysfunction, quality of life or anxiety and depression. Future clinical trials should include a full report of their methods, including adequate masking, consistent assessment of all patient-important outcomes, including potential treatment-related adverse events, and appropriate sample sizes.

Recent advances in managing chronic prostatitis/chronic pelvic pain syndrome

Chronic prostatitis/chronic pelvic pain syndrome is a common disorder seen in men under the age of 50 and has a considerable negative impact on quality of life; it is a complex and difficult condition to treat, owing to its wide symptomatology. In order to effectively treat this condition, the UPOINT system was developed: it allows clinical profiling of a patient's symptoms into six broad categories (urinary symptoms, psychological dysfunction, organ-specific symptoms, infectious causes, neurologic dysfunction, and tenderness of the pelvic floor muscles) to allow individualized and multimodal therapy. In this review, we present the most recent advancements in the treatment of chronic prostatitis/chronic pelvic pain syndrome from the past few years.

Effect of thermobalancing therapy on chronic prostatitis and chronic pelvic pain syndrome

Background:

Type-III chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is the most common type of prostatitis.

Patients and methods:

We ascertained the effect of ‘thermobalancing’ therapy (TT; using Dr Allen’s therapeutic device (DATD)) on CP/CPPS. We measured National Institute of Health Chronic Prostatitis Symptom Index (NIH-CPSI) scores, prostatic volume (PV), and maximum urinary flow rate (Qmax) in one group of 45 patients who underwent TT and a control group that did not have TT, and compared these parameters between groups.

Results:

Baseline evaluation (pretreatment) of both groups showed no significant difference with regard to age, NIH-CPSI score, PV or Qmax. Pain score decreased in both groups but, in the treatment group, the difference between scores was considerably higher (8.72:1) than that of the non-treatment group. TT decreased quality of life (QoL) significantly whereas, in the control group, it decreased QoL slightly. TT reduced PV significantly whereas, in the control group, PV increased. TT increased Qmax significantly in CP/CPPS patients whereas, in the control group, TT did not elicit a significant change in Qmax.

Conclusions:

Six-month TT with DATD: (a) reduces CP/CPPS symptoms and improves QoL; (b) reduces PV; (c) increases Qmax. TT could be effective treatment for CP/CPPS.

Contemporary Management of Chronic Prostatitis/Chronic Pelvic Pain Syndrome

CONTEXT

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common condition that causes severe symptoms, bother, and quality-of-life impact in the 8.2% of men who are believed to be affected. Research suggests a complex pathophysiology underlying this syndrome that is mirrored by its heterogeneous clinical presentation. Management of patients diagnosed with CP/CPPS has always been a formidable task in clinical practice. Due to its enigmatic etiology, a plethora of clinical trials failed to identify an efficient monotherapy.

OBJECTIVE

A comprehensive review of published randomized controlled trials (RCTs) on the treatment of CP/CPPS and practical best evidence recommendations for management.

EVIDENCE ACQUISITION

Medline and the Cochrane database were screened for RCTs on the treatment of CP/CPPS from 1998 to December 2014, using the National Institutes of Health Chronic Prostatitis Symptom Index as an objective outcome measure. Published data in concert with expert opinion were used to formulate a practical best evidence statement for the management of CP/CPPS.

EVIDENCE SYNTHESIS

Twenty-eight RCTs identified were eligible for this review and presented. Trials evaluating antibiotics, α-blockers, anti-inflammatory and immune-modulating substances, hormonal agents, phytotherapeutics, neuromodulatory drugs, agents that modify bladder function, and physical treatment options failed to reveal a clear therapeutic benefit. With its multifactorial pathophysiology and its various clinical presentations, the management of CP/CPPS demands a phenotypic-directed approach addressing the individual clinical profile of each patient. Different categorization algorithms have been proposed. First studies applying the UPOINTs classification system provided promising results. Introducing three index patients with CP/CPPS, we present practical best evidence recommendations for management.

CONCLUSIONS

Our current understanding of the pathophysiology underlying CP/CPPS resulting in this highly variable syndrome does not speak in favor of a monotherapy for management. No efficient monotherapeutic option is available. The best evidence-based management of CP/CPPS strongly suggests a multimodal therapeutic approach addressing the individual clinical phenotypic profile.

PATIENT SUMMARY

Chronic prostatitis/chronic pelvic pain syndrome presents a variable syndrome. Successful management of this condition is challenging. It appears that a tailored treatment strategy addressing individual patient characteristics is more effective than one single therapy.

Updates on therapies for chronic prostatitis/chronic pelvic pain syndrome

Prostatitis comprises of a group of syndromes that affect almost 50% of men at least once in their lifetime and makeup the majority of visits to the Urology Clinics. After much debate, it has been divided into four distinct categories by National Institutes of Health namely (1) acute bacterial prostatitis; (2) chronic bacterial prostatitis; (3) chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) which is further divided into inflammatory and non-inflammatory CP/CPPS; and (4) asymptomatic inflammatory prostatitis. CP/CPPS has been a cause of great concern for both patients and physicians because of the lack of presence of thorough information about the etiological factors along with the difficult-to-treat nature of the syndrome. For the presented manuscript an extensive search on PubMed was conducted for CP/CPPS aimed to present an updated review on the evaluation and treatment options available for patients with CP/CPPS. Several diagnostic criteria’s have been established to diagnose CP/CPPS, with prostatic/pelvic pain for at least 3 mo being the major classifying symptom along with the presence of lower urinary tract symptoms and/or ejaculatory pain. Diagnostic tests can help differentiate CP/CPPS from other syndromes that come under the heading of prostatitis by ruling out active urinary tract infection and/or prostatic infection with uropathogen by performing urine cultures, Meares-Stamey Four Glass Test, Pre- and Post-Massage Two Glass Test. Asymptomatic inflammatory prostatitis is confirmed through prostate biopsy done for elevated serum prostate-specific antigen levels or abnormal digital rectal examination. Researchers have been unable to link a single etiological factor to the pathogenesis of CP/CPPS, instead a cluster of potential etiologies including atypical bacterial or nanobacterial infection, autoimmunity, neurological dysfunction and pelvic floor muscle dysfunction are most commonly implicated. Initially monotherapy with anti-biotics and alpha adrenergic-blockers can be tried, but its success has only been observed in treatment naïve population. Other pharmacotherapies including phytotherapy, neuromodulatory drugs and anti-inflammatories achieved limited success in trials. Complementary and interventional therapies including acupuncture, myofascial trigger point release and pelvic floor biofeedback have been employed. This review points towards the fact that treatment should be tailored individually for patients based on their symptoms. Patients can be stratified phenotypically based on the UPOINT system constituting of Urinary, Psychosocial, Organ-specific, Infectious, Neurologic/Systemic and symptoms of muscular Tenderness and the treatment algorithm should be proposed accordingly. Treatment of CP/CPPS should be aimed towards treating local as well as central factors causing the symptoms. Surgical intervention can cause significant morbidity and should only be reserved for treatment-refractory patients that have previously failed to respond to multiple drug therapies.

Multimodal therapy for category III chronic prostatitis/chronic pelvic pain syndrome in UPOINTS phenotyped patients

The complex network of etiological factors, signals and tissue responses involved in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) cannot be successfully targeted by a single therapeutic agent. Multimodal approaches to the therapy of CP/CPPS have been and are currently being tested, as in the frame of complex diagnostic-therapeutic phenotypic approaches such as the urinary, psychosocial, organ-specific, infection, neurological and muscle tenderness (UPOINTS) system. In this study, the effect of combination therapy on 914 patients diagnosed, phenotyped and treated in a single specialized prostatitis clinic was analyzed. Patients received α-blockers, Serenoa repens (S. repens) extracts combined or not with supplements (lycopene and selenium) and, in the presence of documented or highly suspected infection, antibacterial agents. Combination treatment induced marked and significant improvements of National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) prostatitis symptom scores, International Index of Erectile Function (IIEF) sexual dysfunction scores, urinary peak flow rates and bladder voiding efficiency. These improvements, assessed after a 6-month course of therapy, were sustained throughout a follow-up period of 18 months. A clinically appreciable reduction of ≥6 points of the total NIH-CPSI score was achieved in 77.5% of patients subjected to combination therapy for a period of 6 months. When the patients were divided in two cohorts, depending on the diagnosis of CP/CPPS [inflammatory (IIIa) vs. non-inflammatory (IIIb) subtypes], significant improvements of all signs and symptoms of the syndrome were observed in both cohorts at the end of therapy. Intergroup comparison showed that patients affected by the IIIa sub-category of CP/CPPS showed more severe signs and symptoms (NIH-CPSI total, pain and quality of life impact scores, and Qmax) at baseline when compared with IIIb patients. However, the improvement of symptoms after therapy was significantly more pronounced in IIIa patients when compared with IIIb patients. In contrast to current opinion, the evidence emerging from the present investigation suggests that the inflammatory and non-inflammatory sub-categories of CP/CPPS may represent two distinct pathological conditions or, alternatively, two different stages of the same condition. In conclusion, a simple protocol based on α-blockers, S. repens extracts and supplements and antibacterial agents, targeting the urinary, organ specific and infection domains of UPOINTS, may induce a clinically appreciable improvement of the signs and symptoms of CP/CPPS in a considerable percentage of patients. In patients not responding sufficiently to such therapy, second-line agents (antidepressants, anxiolytics, muscle relaxants, 5-phosphodiesterase inhibitors and others) may be administered in order to achieve a satisfactory therapeutic response.