Unintended Consequences: A Review of Pharmacologically-Induced Priapism

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.

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.

A population-based analysis of predictors of penile surgical intervention among inpatients with acute priapism

While consensus exists regarding risk factors for priapism, predictors of operative intervention are less well established. We assessed patient and hospital-level predictors associated with penile surgical intervention (PSI) for patients admitted with acute priapism, as well as length of stay (LOS) and total hospital charges using the National Inpatient Sample (2010-2015). Inpatients with acute priapism were stratified by PSI, defined as penile shunts, incisions, and placement of penile prostheses, exclusive of irrigation procedures. Survey-weighted logistic regression models were utilized to assess predictors of PSI. Negative binomial regression and generalized linear models with logarithmic transformation were used to compare PSI to LOS and total hospital charges, respectively. Among 14,529 weighted hospitalizations, 4,953 underwent PSI. Non-Medicare insurances, substance abuse, and ≥3 Elixhauser comorbidities had increased odds of PSI. Conversely, Black patients, sickle cell disease, alcohol abuse, neurologic diseases, malignancies, and teaching hospitals had lower odds. PSI coincided with shorter median LOS (adjusted IRR: 0.62; p < 0.001) and lower ratio of the mean hospital charges (adjusted Ratio: 0.49; p < 0.001). Additional subgroup analysis revealed penile incisions and shunts primarily associated with reduced LOS (adjusted IRR: 0.66; p < 0.001) and total hospital charges (adjusted Ratio: 0.49; p < 0.001). Further work is required to understand predictors of poor outcomes in these populations.

Gabapentin-Induced Priapism

Priapism is defined as an erection that lasts longer than four hours, is unrelated to sexual interest or stimulation, and is unrelieved by orgasm. The ischemic subtype is a urologic emergency and is often caused by medication side effects, most notably selective serotonin reuptake inhibitors and trazodone. We present the case of ischemic priapism thought to be caused by the recent initiation of gabapentin.

Clitoral Priapism in a Transgender Male

Introduction

Clitoral priapism due to venous outflow obstruction is a rare event and medical emergency. Androgen-induced clitoromegaly in transgender men has not been previously identified as a risk factor.

Aims

Advance current knowledge on identification and treatment of clitoral priapism in the transgender male.

Methods

A 32 year-old presurgical transgender male underwent gender-affirming laparoscopic total hysterectomy and bilateral salpingo-oöphorectomy without incident. Seven days postop, he developed progressive and painful clitoral engorgement that was persistent. Examination and imaging were consistent with clitoral priapism.

Results

Clitoral priapism was treated with adrenergic drugs (imipramine and pseudoephedrine) with rapid resolution of symptoms.

Conclusion

Clitoral priapism is a rare phenomenon usually associated with use of a psychotropic medication. Whether clitoromegaly secondary to androgen administration in transgender men is a risk factor for this rare medical emergency is unknown. Prompt recognition and treatment is paramount.

Kusko RE, Singhal E, Kauffman RP. Clitoral Priapism in a Transgender Male. Sex Med 2021;9:100431.

Loxapine-Induced Priapism: A Case Report and Review of the Literature on Antipsychotic-Induced Priapism

In this case report, a patient with schizophrenia experienced recurrent priapism while undergoing treatment of acute psychosis. This necessitated a review of the emergent treatment of priapism and discussion of the difficulties in treating priapism in a patient with acute psychosis. Therefore, this case report explores multiple possible etiologies of priapism within the realm of psychiatric care, reviews the proposed mechanisms of medication-induced priapism, and considers the psychopharmacological concepts that pertain to antipsychotic selection in the context of antipsychotic-induced priapism.

Priapism following a juvenile Russell's viper bite: An unusual case report

Following a bite from a juvenile Russell's viper (Daboia russelii), a priapism (painful erection) developed rapidly in a 16-year-old male and only subsided after administration of antivenom 3 hours later. Potential mechanisms for this snakebite-induced priapism are unclear but likely due to venom toxins causing nitric oxide (NO) release and subsequent vasodilation of endothelium in the corpus cavernosum, although the possible involvement of other mechanisms cannot be ruled out. We strongly believe that this unusual case report may lead to further scientific research in order to improve the clinical understanding of the pathophysiology of envenomation due to Russell's viper bites. Although it is too early to speculate, further research may also discover the possibilities of developing venom-based candidate molecules to treat sexual dysfunction in males and females.

A Review of Antipsychotics and Priapism

INTRODUCTION

Pharmacologically induced priapism is now the most common cause of priapism, with approximately 50% of drug-related priapism being attributed to antipsychotic usage. The majority of pharmacologic priapism is believed to result in ischemic priapism (low flow), which may lead to irreversible complications, such as erectile dysfunction. It is imperative that prescribing physicians be aware of potentially inciting medications.

OBJECTIVES

To identify medications, specifically antipsychotics, associated with priapism and prolonged erections and understand the rates and treatment of these side effects.

METHODS

A PubMed search of all articles available on the database relating to priapism, prolonged erections, and antipsychotics was performed.

RESULTS

Various typical and atypical antipsychotic drugs (APDs) have been implicated in pharmacologically induced priapism. In addition to dopaminergic and serotoninergic receptors, APDs have affinities for a wide array of other receptors in the central nervous system, including histaminergic, noradrenergic, and cholinergic receptors. Although the exact mechanism is unknown, the most commonly proposed mechanism of priapism associated with APDs is α-adrenergic blockade in the corpora cavernosa of the penis. Priapism appears in only a small fraction of men using medications with α1-receptor-blocking properties, indicating differential sensitivities to the α-blocking effect among men, and/or additional risk factors that may contribute to the development of priapism. The best predictor for the subsequent development of priapism is a past history of having prolonged and painless erections. The acute management algorithm of APD-induced priapism is the same as for other causes of low-flow priapism.

CONCLUSION

Clinicians should educate patients treated with antipsychotics about the potential for priapism and its sequelae including permanent erectile dysfunction. Appropriate patient education will raise awareness, encourage early reporting, and help reduce the long-term consequences associated with priapism through early intervention. Hwang T, Shah T,Sadeghi-NejadH. A Review of Antipsychotics and Priapism. Sex Med Rev 2021;9:464-471.

Pharmacologically-induced Recreational Priapism: Case Report and Review

Introduction

Priapism, a time-sensitive urologic emergency, is associated with hematologic disorders, malignancies, trauma, pharmaceuticals, and recreational drugs.

Case Report

A 51-year-old male presented with 36 hours of priapism after recreational use of nonprescribed pharmaceuticals including an oral phosphodiesterase inhibitor and intracorporally injected erectile medications, together with unspecified quantities of cocaine and alcohol. Venous blood gas confirmed ischemic priapism. Detumescence was achieved with intracavernosal phenylephrine injection, aspiration, and irrigation.

Conclusion

This case highlights the risk that recreational use of vasoactive medications by patients who seek to prolong sexual activity may lead to delayed presentation for ischemic priapism.

Malignant Priapism - What Do We Know About It?

Malignancy as an etiological factor involved in priapism pathogenesis is rare. Malignant priapism (MP) can arise as a result of penile tumor invasion, either from primary penile tumors or from metastatic penile tumors, or due to hematological malignancies. Non-urological penile metastases are associated with significant worse prognosis compared to urological penile metastases, the appearance of priapism in such cases affecting even more the prognosis and the survival of these patients. Patients diagnosed with hematological malignancies and priapism present significant higher survival rates compared to those who develop MP in the context of a non-hematological malignancy, this being related to the fact that hematological malignancies are more sensitive to chemo- and radiotherapy. Most malignant priapism cases are ischemic; therefore the management should be based on the initial steps of the IP therapeutic protocol. Considering the trigger factor that has led to the priapic event specific oncologic treatment can be added as well.

Possible Propofol-Induced Priapism Following Cardiac Catheter Ablation in a Teenager

Patient: Male, 16-year-old

Final Diagnosis: Priapism

Symptoms: Erectile

Medication: Propofol

Clinical Procedure: Catheter ablation

Specialty: Cardiology