Are We Overstating the Risk of Priapism With Oral Phosphodiesterase Type 5 Inhibitors?

A narrative review of initial treatment for ischemic priapism

Priapism is a rare condition characterized by prolonged and often painful penile erection unrelated to sexual stimulation. Ischemic priapism, the most common subtype, requires immediate attention to prevent irreversible damage to erectile tissue. This narrative review explores the initial management strategies for ischemic priapism. Intracavernosal phenylephrine injection and aspiration with or without irrigation are recommended as first-line treatments, with alternative options available depending on clinical settings and patient factors. While guidelines offer clear recommendations for priapism lasting more than 4 h, management of shorter-duration cases remains challenging due to limited evidence.

[Priapism]

Priapism is defined as penile erection lasting more than four hours that is unrelated to sexual arousal. Priapism is classified based on the oxygenation of the penile tissue into ischemic and non-ischemic subtypes. As the most common form, ischemic priapism is usually associated with pain and carries a significant risk of permanent loss of erectile function; thus, rapid intervention is necessary. Initial therapy consists of corporal aspiration and injection of sympathomimetic agents. If detumescence is not achieved, a cavernosal shunt is necessary. Non-ischemic priapism is less common than the ischemic type and is usually the result of perineal trauma. In this subtype, there is usually no pain and treatment is initially conservative. Recurrent (stuttering) priapism is a variant of the ischemic subtype, but is self-limiting and usually occurs during sleep with a duration of less than three to four hours. In the case of prolonged erection, therapy is analogous to that of the ischemic subtype.

Ischemic priapism caused by self intracavernous injection of tadalafil

Introduction

We present a case of ischemic priapism caused by self intracavernous injection of tadalafil.

Case presentation

A 77-year-old man developed priapism due to self-injection of tadalafil into the corpus cavernosum. He presented to our hospital 2 days after the development of priapism and severe penile pain. The blood gas analysis of the corpus cavernosum revealed ischemic priapism. At first, we performed percutaneous distal shunt (T-shunt) and cavernosal irrigation, resulting in slight improvement of penile tumescence. Several hours later, penile tumescence and severe pain reappeared. Bilateral proximal (corpora-spongiosal) shunt was performed under anesthesia again. Penile tumescence was slowly and gradually relieved. His erectile function was declined.

Conclusion

We experienced a case of priapism due to self intracavernous administration of tadalafil who needed a proximal shunt to relieve the severe penile pain. This case report may serve as a warning for physicians and patients not to use phosphodiesterase 5 inhibitor inappropriately.

Medications mostly associated with priapism events: assessment of the 2015-2020 Food and Drug Administration (FDA) pharmacovigilance database entries

A range of drugs have a direct role in triggering ischaemic priapism. We aimed at identifying: a) which medications are associated with most priapism-reports; and, b) within these medications, comparing their potential to elicit priapism through a disproportionality analysis. The FDA Adverse Event Reporting System (FAERS) database was queried to identify those drugs associated the most with priapism reports over the last 5 years. Only those drugs being associated with a minimum of 30 priapism reports were considered. The Proportional Reporting Ratios (PRRs), and their 95% confidence intervals were computed. Out of the whole 2015-2020 database, 1233 priapism reports were identified, 933 of which (75.7%) were associated with 11 medications with a minimum of 30 priapism-reports each. Trazodone, olanzapine and tadalafil showed levels of disproportionate reporting, with a PRR of 9.04 (CI95%: 7.73-10.58), 1.55 (CI95%: 1.27-1.89), and 1.42 (CI95%: 1.10-1.43), respectively. Most (57.5%) of the reports associated with the phosphodiesterase type 5 inhibitors (PDE5Is) were related with concomitant priapism-eliciting drugs taken at the same time and/or inappropriate intake/excessive dosage. Patients taking trazodone and/or antipsychotics need to be aware of the priapism-risk; awareness among prescribers would help in reducing priapism-related detrimental sequelae; PDE5I-intake is not responsible for priapism by itself, when appropriate medical supervision is provided.

Oral phosphodiesterase type 5 inhibitors and priapism: A VigiBase analysis

PURPOSE

To explore the differences of priapism events among a diverse cohort taking erectogenic medicines (i.e., phosphodiesterase type 5 inhibitors [PDE5i] and intracavernousal drugs).

METHODS

We queried the World Health Organization global database of individual case safety reports (VigiBase) for records of the adverse drug reactions (ADR) with sildenafil, tadalafil, avanafil, vardenafil, papaverine, and alprostadil. Disproportionality analyses (case/non-case approach) were performed to assess the reporting odds ratio (ROR) of priapism reporting in PDE5i consumers compared to intracavernousal drug recipients.

RESULTS

From a total of 133 819 ADR events for erectogenic medications, 632 were priapism (PDE5is: n = 550, 0.41%; intracavernousal drugs: n = 82, 9.92%). Priapism disproportionality signals from intracavernousal drugs were 25 times stronger than PDE5is (ROR = 34.7; confidence interval [CI] 95%: 27.12-43.94 vs. ROR = 1.38; 95% CI: 1.24-1.54). For all PDE5i agents, the 12-17 years age group had the highest ROR (9.49, 95% CI: 3.76-19.93) followed by 2-11 years (4.31, 95% CI: 1.57-9.4). Disproportionality signals for consumers under 18 for both all PDE5is as a whole (ROR = 4.57, 95% CI: 2.48-7.73) and sildenafil (ROR = 4.89, 95% CI: 2.51-8.62) were stronger than individuals 18 or older (ROR = 1.06, 95% CI: 0.93-1.21 and ROR = 1.08, 95% CI: 0.91-1.26, respectively).

CONCLUSIONS

PDE5i use shows disproportionate priapism signals which are higher in young patients.

Adverse reactions of PDE5 inhibitors: An analysis of the World Health Organization pharmacovigilance database

BACKGROUND

Despite their efficacy and general safety, rare but devastating adverse drug reactions have been associated with phosphodiesterase type 5 inhibitors.

OBJECTIVES

To determine the safety profile of oral phosphodiesterase type 5 inhibitors with a particular focus on priapism and malignant melanoma.

MATERIALS AND METHODS

In this case-non-case study, we queried the individual case safety reports for phosphodiesterase type 5 inhibitors within the World Health Organization global database of individual case safety reports (VigiBase) between 1983 and 2021. We included all individual case safety reports for sildenafil, tadalafil, vardenafil, and avanafil in men. For comparison, we also extracted the safety data from the Food and Drug Administration trials for these drugs. We assessed the safety profile of phosphodiesterase type 5 inhibitors by disproportionality analysis by measuring reporting odds ratio for their most commonly reported adverse drug reactions, once for all phosphodiesterase type 5 inhibitor reports and once for reports of oral phosphodiesterase type 5 inhibitor use in adult men (≥18 years old) with sexual dysfunction.

RESULTS

A total of 94,713 individual case safety reports for phosphodiesterase type 5 inhibitors were extracted. A total of 31,827 individual case safety reports were identified relating to adult men taking oral sildenafil, tadalafil, vardenafil, or avanafil for sexual dysfunction. The most common adverse drug reactions included poor drug efficacy (42.5%), headache (10.4% vs. 8.5%-27.6% [Food and Drug Administration]), abnormal vision (8.4% vs. ≤4.6% [Food and Drug Administration]), flushing (5.2% vs. 5.1%-16.5% [Food and Drug Administration]), and dyspepsia (4.2% vs. 3.4%-11.1% [Food and Drug Administration]). Priapism showed significant signals for sildenafil (reporting odds ratio = 13.81, 95% confidence interval: 11.75-16.24), tadalafil (reporting odds ratio = 14.54, 95% confidence interval: 11.56-18.06), and vardenafil (reporting odds ratio = 14.12, 95% confidence interval: 8.36-22.35). Comparing with other medications in VigiBase, sildenafil (reporting odds ratio = 8.73, 95% confidence interval: 7.63-9.99) and tadalafil (reporting odds ratio = 4.25, 95% confidence interval: 3.19-5.55) had significantly higher reporting odds ratios for malignant melanoma.

CONCLUSION

Phosphodiesterase type 5 inhibitors show significant signals correlating with priapism among a large international cohort. Further clinical study is needed to elucidate whether this is from proper or inappropriate use or other confounding conditions, as analysis of pharmacovigilance data does not allow for quantifying the clinical risk. Also, there appears to be a relationship between phosphodiesterase type 5 inhibitor use and malignant melanoma, which warrants additional study to better understand causation.

Safety profile and signal detection of phosphodiesterase type 5 inhibitors for erectile dysfunction: a Food and Drug Administration Adverse Event Reporting System analysis

Background

Phosphodiesterase type 5 inhibitors (PDE5Is) are generally well tolerated but have been associated with uncommon and significant adverse events (AEs).

Aim

This study aims to investigate and compare the characteristics of AEs associated with PDE5Is used for erectile dysfunction and identify any safety signals in a postmarketing surveillance database between 2010 and 2021.

Methods

A descriptive analysis was conducted for all AEs reported to the Food and Drug Administration Adverse Event Reporting System for 4 PDE5Is-avanafil, sildenafil, tadalafil, and vardenafil-indicated for erectile dysfunction between January 2010 and December 2021. The frequency of the most reported AEs and outcomes were identified. A disproportionality analysis based on proportional reporting ratio (PRR) and reporting odds ratio (ROR) was conducted for the most common and clinically important AEs to identify signals to gain insights into potential differences in safety profiles.

Outcomes

The outcome measures of the study are frequency of reported AEs and outcomes following AE.

Results

A total of 29 236 AEs were reported for PDE5Is during the study period. The most reported AE was "drug ineffective" with 7115 reports (24.3%). Eight safety signals were detected across the 4 drugs. Key signals were sexual disorders (PRR, 3.13 [95% CI, 2.69-3.65]; ROR, 3.24 [95% CI, 2.77-3.79]) and death (PRR, 3.17 [2.5-4.01]; ROR, 3.211 [2.52-4.06]) for sildenafil, priapism (PRR, 3.63 [2.11-6.24]; ROR, 3.64 [2.12-6.26]) for tadalafil, and drug administration error (PRR, 2.54 [1.84-3.52]; ROR, 2.6 [1.86-3.63]) for vardenafil. The most reported outcomes were other serious events with 6685 events (67.2%) and hospitalization with 1939 events (19.5%).

Clinical Implications

The commonly reported AEs and detected signals may guide clinicians in treatment decision making for men with erectile dysfunction.

Strengths and Limitations

This is the first comprehensive report and disproportionality analysis on all types of AEs associated with PDE5Is used for erectile dysfunction in the United States. The findings should be interpreted cautiously due to limitations in the Adverse Event Reporting System, which includes self-reports, duplicate and incomplete reports, and biases in reporting and selection. Therefore, establishing a causal relationship between the reported AEs and the use of PDE5Is is uncertain, and the data may be confounded by other medications and indications.

Conclusion

PDE5Is demonstrate significantly increased risks of reporting certain clinically important AEs. While these events are not common, it is imperative to continually monitor PDE5I use at the levels of primary care to national surveillance to ensure safe utilization.

Priapism at Diagnosis of Pediatric Chronic Myeloid Leukemia: Data Derived from a Large Cohort of Children and Teenagers and a Narrative Review on Priapism Management

Pediatric chronic myeloid leukemia (CML) is a very rare malignancy (age-related incidence 0.1/100,000) typically presenting with leucocyte counts >100,000/µL. However, clinical signs of leukostasis are observed at diagnosis in only approximately 10% of all cases and among these, priapism is infrequent. Here, we analyze data from pediatric CML registries on the occurrence of priapism heralding diagnosis of CML in 16/491 (3.2%) boys (median age 13.5 years, range 4-18) with pediatric CML. In the cohort investigated, duration of priapism resulting in a diagnosis of CML was not reported in 5 patients, and in the remaining 11 patients, occurred as stuttering priapism over 3 months (n = 1), over 6 weeks (n = 1), over 1-2 weeks (n = 2), over several days (n = 2), or 24 h (n = 1), while the remaining 4 boys reported continuous erection lasting over 11-12 h. All patients exhibited splenomegaly and massive leukocytosis (median WBC 470,000/µL, range 236,700-899,000). Interventions to treat priapism were unknown in 5 patients, and in the remaining cohort, comprised intravenous fluids ± heparin (n = 2), penile puncture (n = 5) ± injection of sympathomimetics (n = 4) ± intracavernous shunt operation (n = 1) paralleled by leukocyte-reductive measures. Management without penile puncture by leukapheresis or exchange transfusion was performed in 3 boys. In total, 7 out 15 (47%) long-term survivors (median age 20 years, range 19-25) responded to a questionnaire. All had maintained full erectile function; however, 5/7 had presented with stuttering priapism while in the remaining 2 patients priapism had lasted <12 h until intervention. At its extreme, low-flow priapism lasting for longer than 24 h may result in partial or total impotence by erectile dysfunction. This physical disability can exert a large psychological impact on patients' lives. In a narrative review fashion, we analyzed the literature on priapism in boys with CML which is by categorization stuttering or persisting as mostly painful, ischemic (low-flow) priapism. Details on the pathophysiology are discussed on the background of the different blood rheology of hyperleukocytosis in acute and chronic leukemias. In addition to the data collected, instructive case vignettes demonstrate the diagnostic and treatment approaches and the outcome of boys presenting with priapism. An algorithm for management of priapism in a stepwise fashion is presented. All approaches must be performed in parallel with cytoreductive treatment of leukostasis in CML which comprises leukapheresis and exchange transfusions ± cytotoxic chemotherapy.

A review on pharmacological options for the treatment of erectile dysfunction: state of the art and new strategies

INTRODUCTION

Erectile dysfunction (ED) affects between 12.9% and 28.1% of men worldwide, presenting a strong aged-correlated prevalence. Several pharmacological treatments are currently available for ED, which can be classified into oral, injection, and topical/intraurethral therapies.

AREAS COVERED

Extensive research on PubMed/MEDLINE until February 2023 was performed. For each of the aforementioned drug classes, available molecules, and formulations, their efficacy and most common adverse events as well as general guidelines on prescription were investigated and extensively described. A glimpse into future directions regarding ED pharmacotherapy is also present.

EXPERT OPINION

In recent years, there have been significant developments in pharmacological treatments for ED. It is essential for physicians to identify the best treatment option for patients based on their preferences and sexual habits. The treatment approach for ED has shifted from a sequential to a parallel paradigm, where all treatment options are available as first-line therapies. While there are promising regenerative therapies for ED, such as shockwaves and platelet-rich plasma injections, pharmacological treatment is still the most effective option for most patients.

Review of Ischemic and Non-ischemic Priapism

PURPOSE OF REVIEW

Priapism is a rare condition that has different presentations, etiologies, pathophysiology, and treatment algorithms. It can be associated with significant patient distress and sexual dysfunction. We aim to examine the most up-to-date literature and guidelines in the management of this condition.

RECENT FINDINGS

Priapism is a challenging condition to manage for urologists, since the etiology is often multi-factorial and the suggested treatment algorithms are based on small studies and expert anecdotal experience, perhaps due to the rarity of the disorder. Ischemic priapism of less than 24 h can be managed non-surgically in most cases with excellent results. Ischemic priapism of more than 36 h is frequently associated with permanent erectile dysfunction. Management of prolonged priapism with penile shunting still may result in poor erectile function, so penile prosthesis can be discussed in these scenarios.

Socioeconomic Disparities and Risk Factors in Patients Presenting With Ischemic Priapism: A Multi-Institutional Study

OBJECTIVES

To evaluate contemporary clinical presentations of priapism, their association with socioeconomic characteristics, and the role of prescribing providers in priapism episodes in a large cohort of patients managed at 3 major academic health systems.

METHODS

We identified all consecutive patients presenting with ischemic priapism to the emergency departments of three major academic health systems (2014 -2019). Demographic characteristics, priapism etiologies, and clinical management were evaluated. Univariable and multivariable analyses were used to assess the contribution of socioeconomic characteristics and the role of prescribing providers in priapism episodes.

RESULTS

We identified 102 individuals with a total of 181 priapism encounters. Hispanic race, lower income quartile, sickle-cell disease, and illicit drug use were associated with increased risk of recurrent episodes. Of ICI users, 57% received their prescriptions from non-urological medical professionals (NUMPs); the proportion with recurrent episodes was higher for NUMPs compared to urologists (24% vs 0%, P = 0.06) with no demographic differences identified between patients treated by either group.

CONCLUSION

Socioeconomic disparities exist among patients presenting with recurrent episodes of priapism, potentially highlighting systemic issues with access to care and patient education. With most patients who developed ischemic priapism from ICI being prescribed these medications by NUMPs, further investigation is required to elucidate the prescribing and counseling patterns of these providers. Increased awareness of disparities and complications may improve patient safety.

Risk Factors for Surgical Shunting in a Large Cohort With Ischemic Priapism

BACKGROUND

Ischemic priapism is treated with a stepwise algorithm, but some patients may benefit from immediate shunt placement.

AIM

To identify risk factors for surgical shunt placement in a large series of patients with ischemic priapism.

METHODS

We identified all patients presenting to our institution with ischemic priapism from January 2010 to December 2018. Multivariable was performed to assess risk factors for surgical shunting. Receiver operating characteristic curve analysis (Youden Index) was used to assess which cutoff time for the duration of priapism was most predictive requiring shunting.

OUTCOMES

We assess risk factors for surgical shunting and what duration of priapism was most predictive of requiring a shunt.

RESULTS

We identified a total of 169 ischemic priapism encounters from 143 unique patients, of which 26 (15%) encounters resulted in a surgical shunt. Patients treated with a shunt had longer priapism durations than those without (median 36 vs 10 hours, P < .001). Independent predictors of a surgical shunt on multivariate logistic regression were the duration of priapism in hours (odds ratio: 1.05, 95% confidence interval: 1.02-1.10; P < .001) and history of prior priapism (odds ratio: 3.15, 95% confidence interval: 1.03-9.60; P = .045). Receiver operating characteristic curve analysis using priapism duration to predict the need for shunt generated an area under curve of 0.83. A duration of 24 hours correlated to a sensitivity of 0.77 and specificity of 0.90.

CLINICAL IMPLICATIONS

These results can be used to counsel future patients and assist in the decision-making process for providers.

STRENGTHS & LIMITATIONS

This is one of the largest series of priapism in the literature. Most (74%) of the priapism were due to intracavernosal injections so the results may not be generalizable to populations with different priapism etiologies.

CONCLUSION

In this study of 169 priapism encounters, we found that the priapism duration and history of prior priapism were independent predictors of surgical shunt placement. These results can aid urologists in the counseling and decision-making process of these challenging cases. Zhao H, Dallas K, Masterson J, et al. Risk Factors for Surgical Shunting in a Large Cohort With Ischemic Priapism. J Sex Med 2020;17:2472-2477.