Ketoconazole and prednisone to prevent recurrent ischemic priapism

Update on Treatment Options for Stuttering Priapism

Purpose of Review

There is a paucity of peer-reviewed evidence to guide medical management of stuttering priapism. The purpose of this review is to summarize the current understanding regarding the pathophysiology of priapism and management options for stuttering priapism.

Recent Findings

Conducting large-scale, randomized, placebo-controlled trials that elucidate the optimal treatment of stuttering priapism is challenging. Therefore, recent treatment guidelines are based upon small case series, retrospective studies, and expert opinions. Nonetheless, multiple compounds from various drug classes have shown promise in treating stuttering priapism, and a few pharmacotherapies such as Crizanlizumab are currently under active investigation.

Summary

Stuttering priapism is an under-investigated disorder with a complex pathophysiology. Currently, there is no wildly adopted universal therapeutic strategy. Further research is warranted to identify the appropriate treatment of stuttering priapism and to determine the long-term side effects of current pharmacotherapies.

An update on the management algorithms of priapism during the last decade

Priapism is a persistent penile erection lasting longer than 4 hours, that needs emergency management. This disorder can induce irreversible erectile dysfunction. There are three subtypes of priapism: ischemic, non-ischemic, and stuttering priapism. If the patient has ischemic priapism (IP) of less than 24-hours (h) duration, the initial management should be a corporal blood aspiration followed by instillation of phenylephrine into the corpus cavernosum. If sympathomimetic fails or the patient has IP from 24 to 48h, surgical shunts should be performed. It is recommended that distal shunts should be attempted first. If distal shunt failed, proximal, venous shunt, or T-shunt with tunneling could be performed. If the patient had IP for 48 to 72h, proximal and venous shunt or T-shunt with tunneling is indicated, if those therapies failed, a penile prosthesis should be inserted. Non-ischemic priapism (NIP) is not a medical emergency and many patients will recover spontaneously. If the NIP does not resolve spontaneously within six months or the patient requests therapy, selective arterial embolization is indicated. The goal of the management of a patient with stuttering priapism (SP) is the prevention of future episodes. Phosphodiesterase type 5 (PDE5) inhibitor therapy is considered an effective tool to prevent stuttering episodes but it is not validated yet. The management of priapism should follow the guidelines as the future erectile function is dependent on its quick resolution. This review briefly discusses the types, pathophysiology, and diagnosis of priapism. It will discuss an updated approach to treat each type of priapism.

Medical treatment of recurrent ischaemic priapism: a review of current molecular therapeutics and a new clinical management paradigm

OBJECTIVES

To examine the current molecular therapeutics in the medical treatment of recurrent ischemic priapism (RIP). To propose a stepwise clinical management paradigm for the treatment of RIP.

METHODS

We performed a literature search using the PubMed database for the terms 'recurrent ischemic priapism' and 'stuttering priapism' up until December 2020. We assessed pre-clinical and clinical studies regarding medical management of RIP and molecular pathophysiology. Case series and randomized trials were evaluated by study quality and patient outcomes to determine a potential clinical management scheme.

RESULTS

Recent research has fostered an improved understanding of the underlying molecular pathophysiology of RIP that has paved the way forward for developing new therapeutic agents. Medications targeting neurovascular, hormonal and haematological mechanisms associated with RIP show great promise towards remedying this condition. A host of therapeutic agents operating across different mechanistic directions may be implemented according to a clinical management scheme to potentially optimize RIP outcomes.

CONCLUSION

RIP remains a medically neglected condition with current management focused on treating the acute condition rather than modulating the course of disease. Continued research into the molecular mechanisms of RIP and standardized clinical pathways can improve the quality of care for patients suffering from this condition.

Mechanisms underlying priapism in sickle cell disease: targeting and key innovations on the preclinical landscape

Introduction: Priapism is prolonged penile erection in the absence of sexual arousal or desire and is a devastating condition affecting millions of patients with sickle cell disease (SCD) globally. Available drug treatments for SCD-related priapism remain limited and have been primarily reactive rather than preventive. Hence, there is an unmet need for new drug targets and pharmacologic therapies.Areas covered: We examine the molecular mechanisms underlying SCD-associated priapism evaluated mostly in animal models. In mouse models of SCD, molecular defects of priapism operating at the cavernous tissue level include reduced tonic NO/cGMP signaling, elevated oxidative/nitrosative stress, vascular adhesion molecule derangements, excessive adenosine and opiorphin signaling, dysregulated vasoconstrictive RhoA/ROCK signaling, and testosterone deficiency. We discuss the consequences of downregulated cGMP-dependent phosphodiesterase type 5 (PDE5) activity in response to these molecular signaling derangements, as the main effector mechanism causing unrestrained cavernous tissue relaxation that results in priapism.Expert opinion: Basic science studies are crucial for understanding the underlying pathophysiology of SCD-associated priapism. Understanding the molecular mechanisms could unearth new therapeutic targets for this condition based on these mechanisms. Treatment options should aim to improve deranged erection physiology regulatory signaling to prevent priapism and potentially restore or preserve erectile function.

Dutasteride in the long-term management of stuttering priapism

Background

The objective of this study is to review our 12-year experience with the 5-α reductase inhibitor dutasteride as a potential long-term treatment option for stuttering priapism. Dutasteride has a uniquely long half-life of 35 days which offers a theoretical advantage as a chronic therapy for management of stuttering priapism.

Methods

We retrospectively reviewed patients with stuttering priapism in our database from 2006-2018 treated with dutasteride. Men with concurrent use of medications other than dutasteride to treat stuttering priapism were excluded. Patients were started on a dose of 0.5 mg daily and tapered to a more infrequent dosing schedule, ranging from 0.5 mg every other day to once weekly. The frequency of priapism episodes before and after initiation of dutasteride therapy was analyzed.

Results

Among 21 cases, 13 patients met our inclusion criteria (mean age 43 years). Median follow-up on daily dutasteride was 79 days, and median follow-up on tapered dutasteride was 607 days. A total of 11/13 (85%) men treated with dutasteride had some degree of improvement-5/13 (38%) had complete resolution of their symptoms and 6/13 (46%) had reduced frequency and/or severity of their episodes. Among 5/13 (38%) men who had >2 emergency room (ER) visits for ischemic priapism prior to therapy, most (3/5, 60%) did not require any ER visits while on dutasteride therapy. Among the five men who received chronic, tapered-dose therapy, all reported continued suppression of priapistic episodes. Among 4 patients with sickle cell disease (SCD), 3/4 (75%) ultimately chose more invasive therapy including androgen deprivation therapy (ADT) and penile prosthesis. Side effects were minimal and included gynecomastia (8%), decreased libido (8%), and fatigue (8%).

Conclusions

In patients with stuttering priapism, daily dutasteride therapy is a promising treatment option to reduce the frequency and severity of priapistic episodes without significant side effects. Therapy can effectively be tapered to once weekly dosing without a reduction in efficacy.

Daily use of phosphodiesterase type 5 inhibitors as prevention for recurrent priapism

Summary Objective: The pathogenesis of recurrent priapism is currently being investigated based on the regulation of the phosphodiesterase 5 (PDE5) enzyme. We explored the daily use of PDE5 inhibitors to treat and prevent priapism recurrences. Method: We administered PDE5 inhibitors using a long-term therapeutic regimen in seven men with recurrent priapism, with a mean age of 29.2 years (range 21 to 35 years). Six men (85.7%) had idiopathic priapism recurrences and one man (24.3%) had sickle cell disease-associated priapism recurrences. Tadalafil 5 mg was administered daily. The mean follow-up was 6.6 months (range 3 to 12 months). Results: Daily long-term oral PDE5 inhibitor therapy alleviated priapism recurrences in all patients. Five (71.4%) had no episodes of priapism and two (28.6%) referred decrease in their episodes of priapism. All patients referred improvement in erectile function. Conclusion: These findings suggest the hypothesis that PDE5 dysregulation exerts a pathogenic role for both sickle cell disease-associated priapism and for idiopathic priapism, and that it offers a molecular target for the therapeutic management of priapism. These preliminary observations suggest that continuous long-term oral PDE5 inhibitor therapy may treat and prevent recurrent priapism.

Contemporary best practice in the evaluation and management of stuttering priapism

Stuttering priapism is rare and under-investigated clinical entity. Although it shares similarities with ischaemic priapism, by definition, stuttering priapism has distinct characteristics that advocate for a different management in the clinical setting. Therefore, the management of stuttering priapism aims primarily to prevent recurrence rather than the resolution of spontaneous attacks. A multimodal approach and the individualization of each case are essential because of the diversity of the condition and the plethora of proposed therapeutic strategies. Understanding the underlying pathophysiology and familiarity with contemporary, past and emerging future agents and therapeutic options are required in order to provide an optimal solution for each patient. In addition, patient counselling and the option to combine therapeutic strategies and challenge second-line therapies are essential weapons in the armament of the urologist. Although further clinical trials and studies are mandatory in order to obtain solid data and provide recommendations, all therapeutic options are analysed, with specific interest in the potential advantages and disadvantages. A structured evaluation procedure is also described.

Management of Recurrent Ischemic Priapism 2014: A Complex Condition with Devastating Consequences

INTRODUCTION

The management of recurrent ischemic priapism (RIP) is not clearly defined. Given the rarity of this condition, most treatment options are supported at best by level 3 or 4 evidence.

AIM

In this article, we review the current literature regarding the pathophysiology and management of RIP and discuss the risks and benefits associated with each option, which includes ketoconazole (KTZ), 5-α-reductase inhibitors and other hormonal therapies, phosphodiesterase type 5 (PDE5) inhibitors, intracavernosal sympathomimetic injection, oral sympathomimetic agents, and other investigational therapies.

METHODS

A comprehensive literature review was performed regarding the management options for RIP.

MAIN OUTCOME MEASURE

To examine the pathophysiology of RIP and evaluate the treatment options.

RESULTS

Multiple agents have been investigated to manage RIP. KTZ, finasteride, anti-androgens, gonadotropin-releasing hormone agonists, and estrogen have been shown to be effective in several reports, though some of these agents may have significant hormonal side effects. PDE5 inhibitors currently appear to be well tolerated in this patient population, though evidence of its efficacy is limited. Intracavernosal α-agonist therapy may be used to treat episodes of priapism after they occur. Very limited data suggest terbutaline, oral α-agonists, digoxin, hydroxyurea, and gabapentin may have a role in RIP management.

CONCLUSIONS

An ideal management strategy for RIP should focus on prevention of priapic episodes using an effective, well-tolerated, cost-effective medication. We currently have several proposed options, with varying efficacy rates and side effect profiles. While significant advancements in our understanding and management of stuttering priapism have been made within the past few years, clearly continuing research and clinical studies are needed to guide our management of this disease process. Hoeh MP and Levine LA. Management of recurrent ischemic priapism 2014: A complex condition with devastating consequences. Sex Med Rev 2015;3:24-35.

Nitrergic Mechanisms for Management of Recurrent Priapism

INTRODUCTION

Priapism is a condition involving prolonged penile erection unrelated to sexual interest or desire. The ischemic type, including its recurrent variant, is often associated with both physical and psychological complications. As such, management is of critical importance. Ideal therapies for recurrent priapism should address its underlying pathophysiology.

AIM

To review the available literature on priapism management approaches particularly related to nitrergic mechanisms.

METHODS

A literature review of the pathophysiology and management of priapism was performed using PubMed.

MAIN OUTCOME MEASURE

Publications pertaining to mechanisms of the molecular pathophysiology of priapism.

RESULTS

Nitrergic mechanisms are characterized as major players in the molecular pathophysiology of priapism. PDE5 inhibitors represent an available therapeutic option with demonstrated ability in attenuating these underlying nitrergic derangements. Several additional signaling pathways have been found to play a role in the molecular pathophysiology of priapism and have also been associated with these nitrergic mechanisms.

CONCLUSION

An increasing understanding of the molecular pathophysiology of priapism has led to the discovery of new potential targets. Several mechanism-based therapeutic approaches may become available in the future.

How I treat priapism

Priapism is a disorder of persistent penile erection unrelated to sexual interest or desire. This pathologic condition, specifically the ischemic variant, is often associated with devastating complications, notably erectile dysfunction. Because priapism demonstrates high prevalence in patients with hematologic disorders, most commonly sickle cell disease (SCD), there is significant concern for its sequelae in this affected population. Thus, timely diagnosis and management are critical for the prevention or at least reduction of cavernosal tissue ischemia and potential damage consequent to each episode. Current guidelines and management strategies focus primarily on reactive treatments. However, an increasing understanding of the molecular pathophysiology of SCD-associated priapism has led to the identification of new potential therapeutic targets. Future agents are being developed and explored for use in the prevention of priapism.

Management of priapism: an update for clinicians

Priapism is a prolonged erection that persists beyond or is unrelated to sexual stimulation. It is associated with significant morbidity: psychological, socioeconomic, and physical, including pain and potentially irreversible compromise of erectile function. There are three major types of priapism: ischemic, nonischemic, and stuttering. Establishing the type of priapism is paramount to safely and effectively treating these episodes. Ischemic priapism represents a urological emergency. Its treatment may involve aspiration/irrigation with sympathomimetic injections, surgical shunts, and as a last resort, penile prosthesis implantation. Nonischemic priapism results from continuous flow of arterial blood into the penis, most commonly related to penile trauma. This is not an emergency and may be managed conservatively initially, as most of these episodes are self-limiting. Stuttering priapism involves recurrent self-limiting episodes of ischemic priapism. The primary goal of therapy is prevention, but acute episodes should be managed in accordance with guidelines for ischemic priapism. In this paper we review the diagnosis and treatment of the three priapism variants, as well as discuss future targets of therapy and novel targets on the horizon.

Is testosterone deficiency a possible risk factor for priapism associated with sickle-cell disease?

PURPOSE

The purpose of this study was to determine the association of testosterone deficiency and priapism in adult men with sickle cell disease (SCD).

METHODS

A cross-sectional study of 50 adult men with SCD (hemoglobin SS) was performed. All patients had early morning blood taken for total and free testosterone, FSH, LH, prolactin, lipid levels, LDH and hematological indices. Patients completed an interviewer-administered questionnaire regarding priapism frequency, duration and treatment. Testosterone deficiency was defined as a serum total testosterone<12 nmol/L (346 ng/dL).

RESULTS

The mean age of the study population was 34.2±8.9 years. Priapism was noted in 24 (48%) patients and was most frequently seen in men between ages 18-25 years. Testosterone deficiency was observed in 11 of the 50 (22%) patients, particularly in 6 of 24 (25%) patients with histories of priapism. There was no difference in mean total testosterone levels in patients with and without a history of priapism (16.7±4.9 nmol/L and 15.4±5.9 nmol/L, respectively) (p=0.43). Similarly, there was no difference in serum LH and FSH levels based on history of priapism.

CONCLUSION

Testosterone deficiency is prevalent in patients with SCD; however, we did not identify an association based on a history of priapism. Larger, prospectively gathered data are needed to define the priapism profile of SCD patients with testosterone deficiency.

Opiorphin is a master regulator of the hypoxic response in corporal smooth muscle cells

Men with sickle cell disease (SCD) risk developing priapism. Recognizing that SCD is a disease of hypoxia, we investigated the effect of hypoxia on gene expression in corporal smooth muscle (CSM) cells. Rat CSM cells in vitro were treated with CoCl2 or low oxygen tension to mimic hypoxia. Hypoxic conditions increased expression of genes previously associated with priapism in animal models. Variable coding sequence a1 (Vcsa1; the rat opiorphin homologue, sialorphin), hypoxia-inducible factor 1a (Hif-1a), and A2B adenosine receptor (a2br) were increased by 10-, 4-, and 6-fold, respectively, by treatment with CoCl2, whereas low oxygen tension caused increases in expression of 3-, 4-, and 1.5-fold, respectively. Sialorphin-treated CSM cells increased expression of Hif-1a and a2br by 4-fold, and vcsa1-siRNA treatment reduced expression by ∼50%. Using a Hif-1a inhibitor, we demonstrated up-regulation of a2br by sialorphin is dependent on Hif-1a, and knockdown of vcsa1 expression with vcsa1-siRNA demonstrated that hypoxic-up-regulation of Hif-1a is dependent on vcsa1. In CSM from a SCD mouse, there was 15-fold up-regulation of opiorphin at a life stage prior to priapism. We conclude that in CSM, opiorphins are master regulators of the hypoxic response. Opiorphin up-regulation in response to SCD-associated hypoxia activates CSM "relaxant" pathways; excessive activation of these pathways results in priapism.

Stuttering priapism: insights into pathogenesis and management

Priapism is defined as a persistent, painful erection that continues beyond, or is unrelated to, sexual stimulation. It may be categorized as either ischemic (low/absent flow) or nonischemic (high flow). Stuttering priapism is a variant of the ischemic type that is characterized by repetitive, transient, painful, self-limiting episodes of priapism. It is associated with various hematological disorders, including sickle cell disease and pharmacological treatments. The consequences of ineffective treatment of priapism are erectile dysfunction and impaired quality of life due to chronic pain and physical disfigurement. Many of the existing medical therapeutic options for treatment of stuttering priapism are nonmechanistic and associated with significant adverse effects. However, the scientific knowledge of stuttering priapism has transitioned in the past few years, from a condition that is poorly understood to one that has borne a burst of evolving molecular science. In this review, the pathophysiology of priapism is discussed, with particular emphasis on new molecular effectors and mechanisms. Novel treatment methods, as well as potential future agents, based on the emerging molecular evidence are discussed.

Priapism is associated with sleep hypoxemia in sickle cell disease

PURPOSE

We assessed penile rigidity during sleep and the relationship of sleep abnormalities with priapism in adults with sickle cell disease.

MATERIALS AND METHODS

This was a case-control study of 18 patients with sickle cell disease and a history of priapism during the previous year, and 16 controls with sickle cell disease. Participants underwent overnight polysomnography and RigiScan® Plus recording to detect penile rigidity oscillations.

RESULTS

The priapism group (cases) showed a higher apnea-hypopnea index and oxyhemoglobin desaturation parameters than controls. A lower positive correlation between the apnea-hypopnea index and oxyhemoglobin desaturation time was observed in cases than in controls (Spearman coefficient ρ = 0.49, p = 0.05 vs ρ = 0.76, p <0.01), suggesting that desaturation events occurred independently of apnea. Two controls and 14 cases had a total sleep time that was greater than 10% with oxyhemoglobin saturation less than 90% but without CO(2) retention. Penile rigidity events were observed during rapid eye movement sleep and during stage 2 of nonrapid eye movement sleep, particularly in cases. The duration of penile rigidity events concomitant to respiratory events was higher in cases than in controls. Regression analysis revealed that the periodic limb movement and desaturation indexes were associated with priapism after adjusting for rapid eye movement sleep and lung involvement. Finally, oxyhemoglobin saturation less than 90% was associated with priapism after adjusting for lung involvement, hyperhemolysis and the apnea-hypopnea index.

CONCLUSIONS

Oxyhemoglobin desaturation during sleep was associated with priapism history. It may underlie the distribution pattern of penile rigidity events during sleep in these patients.

Medical management of ischemic stuttering priapism: a contemporary review of the literature

Priapism is defined as a prolonged and persistent erection of the penis without sexual stimulation. This is a poorly understood disease process with little information on the pathophysiology of this erectile disorder. Complications from this disorder are devastating due to the irreversible erectile damage and resultant erectile dysfunction (ED). Stuttering priapism, though relatively rare, affects a high prevalence of men with sickle-cell disease (SCD) and presents a challenging problem with guidelines for treatment lacking or resulting in permanent ED. The mechanisms involved in the development of priapism in this cohort are poorly characterized; therefore, medical management of priapism represents a therapeutic challenge to urologists. Additional research is warranted, so we can effectively target treatments for these patients with prevention as the goal. This review gives an introduction to stuttering priapism and its clinical significance, specifically with regards to the patient with SCD. Additionally, the proposed mechanisms behind its pathophysiology and a summary of the current and future targets for medical management are discussed.

Priapisme aigu drépanocytaire: analyse de 20 cas traités au CHU de Brazzaville

Objectif

Évaluer les résultats des traitements médicaux et chirurgicaux du priapisme drépanocytaire.

Malades et méthodes

Vingt malades ont été traités pour priapisme drépanocytaire dans les services d’urologie—andrologie et d’hématologie du CHU de Brazzaville, du 1er janvier 1995 au 31 décembre 2005. Les méthodes thérapeutiques ont été les injections intracaverneuses d’étiléfrine et les fistules cavernospongieuses.

Résultats

1) Cinq patients traités sans succès par transfusion et étiléfrine orale ont été secondairement traités avec succès par la technique deWinter; 2) sur cinq patients traités par injection intracaverneuse d’étiléfrine en première intention, on note trois succès et deux échecs, traités avec succès par la technique de Winter; 3) sur dix patients traités par fistules cavernospongieuses selon Winter en première intention, trois ont récidivé et ont été secondairement traités avec succès par la méthode d’Al-Ghorab. Les résultats fonctionnels à long terme sont: 25 % d’absence d’érection, 25 % d’insuffisance d’érection et 50 % d’érection normale.

Conclusion

Le traitement par injection intracaverneuse d’étiléfrine est efficace avant la 24e heure. Au-delà, les fistules cavernospongieuses donnent les meilleurs résultats.

Recent advances in the medical and surgical treatment of priapism

Priapism often is a urological emergency that requires prompt and aggressive therapy. Over the past several years, research has provided better understanding and new insights into the pathophysiology of this disorder. Subsequently, new treatments have been tried and developed. This report focuses on the latest review of therapy for ischemic and nonischemic priapism.

Attenuated RhoA/Rho-kinase signaling in penis of transgenic sickle cell mice

OBJECTIVES

The Ras homolog gene family, member A (RhoA) and its main downstream effector, Rho-kinase (ROCK) are important in maintaining the penis in the flaccid state. The pathophysiology of sickle cell disease-associated priapism is not well defined. We hypothesized that the RhoA/ROCK vasoconstrictive pathways might be involved in the development of priapism. Therefore, the objective of the present study was to evaluate the molecular changes in RhoA and ROCK in an established transgenic sickle cell mouse model of priapism.

METHODS

Two groups of mice were used: wild type (WT; C57BL/6) mice and transgenic sickle cell mice. We evaluated RhoA guanosine triphosphatase and total ROCK activities, as well as ROCK1 and ROCK2 protein expression, in WT and sickle mice penises. We also evaluated the in vivo erectile responses to cavernous nerve stimulation and the frequency and duration of spontaneous erections before and after cavernous nerve stimulation.

RESULTS

Sickle mice demonstrated significantly (P <.05) enhanced erectile responses to cavernous nerve stimulation and frequency of spontaneous erections both before and after cavernous nerve stimulation compared with the WT mice. The sickle mice penises had a significant decline in RhoA guanosine triphosphatase (P <.01) and total ROCK activities (P <.05) compared with the WT mice. A significant (P <.05) reduction in ROCK2 protein expression in sickle mice penises compared with WT mice protein expression. No change in ROCK1 protein expression was observed in either cohort of mice penises.

CONCLUSIONS

These data suggest that sickle cell disease associated-priapism might be contributed by a lack of RhoA/ROCK-mediated vasoconstriction and highlight a novel molecular mechanism in the pathophysiology of priapism.