Priapism from Recreational Intracavernosal Injections in a High-Risk Metropolitan Community

Abstract

Introduction:

Recreational use of intracavernosal injections (ICIs) is a high-risk behavior that involves sharing of these agents by men without physician regulation.

Aim:

To characterize the etiologies and outcomes of priapism at a Los Angeles metropolitan medical center to better understand patterns of usage of recreational ICIs and the public health implications of such practices.

Methods:

With institutional review board approval, we retrospectively reviewed all cases of priapism presenting to the emergency room of a Los Angeles tertiary medical center from 2010 to 2018. We compared outcomes between patients who presented with priapism after recreational ICI and patients who presented with other etiologies.

Main Outcome Measure:

We describe patient characteristics, etiologies, and treatments of priapism at our institution.

Results:

We identified 169 priapism encounters by 143 unique patients. Recreational ICIs accounted for 82 of the 169 priapism encounters (49%). Patients who used recreational injections were younger than those who presented with other etiologies (43.5 years vs 47.5 years; P = .048) and had delayed presentations (median, 12 hours vs 8 hours; P < .0001). There was no statistical difference across groups in the proportion of patients requiring operative intervention (14.6% of recreational ICI users vs 16.1% of all other patients; P = .23). A total of 36 out of 72 patients who used recreational ICIs (50%) were HIV+.

Clinical Implications:

Our study adds to the relatively sparse literature on priapism outcomes. We identify and describe a high-risk population that uses recreational intracavernosal injections.

Strengths & Limitations:

To our knowledge, this is the largest series of priapism encounters. However, the data are retrospective from a single institution, and there is a lack of long-term follow up.

Conclusion:

A large proportion of priapism visits at our institution were attributed to recreational use of ICIs. This is a high-risk patient population that may not be aware of the risks of recreational ICIs and the consequences of priapism. Further effort should be made to increase public and physician awareness of this harmful practice.

INTRODUCTION

Priapism is a urologic emergency that may result in penile fibrosis and permanent erectile dysfunction if not treated immediately.^1,2 Most cases of priapism are ischemic and characterized by a persistent, painful erection with hypoxic and acidotic penile tissue.³ Priapism can arise from a variety of well-described etiologies, including psychiatric medications, leukemia, malignant invasion, sickle cell disease, trauma, and alpha-1 blockers.⁴ Treatment for ischemic priapism depends on the duration of the prolonged erection and can include corporal aspiration and irrigation, corporal injection of sympathomimetic agents, proximal or distal shunting, and insertion of a penile prosthesis.⁵

Iatrogenic causes of priapism from medications used for erectile dysfunction are also well described. Intracavernosal injection (ICI) agents have been shown to cause priapism, highlighting the need for patient education when providers prescribe these treatments.⁶ Recreational use of intracavernosal injections, in which injections are shared in the community without physician regulation or oversight, has not been well characterized in the literature. We sought to investigate the etiology and outcomes of priapism at a Los Angeles metropolitan medical center to better understand patterns of usage of recreational ICIs and the resultant public health implications.

METHODS

After institutional review board approval was obtained, we performed a retrospective review of all patients who had presented to the Cedars-Sinai Medical Center emergency room from January 1, 2010, to July 1, 2018. Charts were reviewed with the assistance of the Cedars-Sinai Honest Enterprise Information Service Research Broker. Patients were identified with an ICD-9 diagnosis code of priapism (607.3) or an ICD-10 diagnosis code of priapism (N48.3), including priapism unspecified (N48.30), priapism due to trauma (N48.31), priapism due to disease classified elsewhere (N48.32), drug-induced priapism (N48.33), and other priapism (N48.39).

Patient age, medical history, priapism etiology, duration of priapism, laboratory studies, and treatments were obtained through manual chart review. Priapism etiologies were determined by each patient’s medications, emergency room triage and physician notes, and the urology consultation note. “Recreational intracavernosal injection” was defined as using an intracavernosal agent without a prescription. We identified cases of recreational intracavernosal injectables when there was documentation of the patient obtaining the injections from a friend or at a party, or if the patient had never seen a physician to obtain the injectables. Priapism etiologies were separately reviewed by a single physician (H.Z.), and any questionable cases were discussed and resolved among 2 separate physicians (J.H. and J.A.). Patients on multiple psychotropic medications were categorized under “other medication.”

We compared characteristics and short-term outcomes between patients who had presented with priapism after recreational ICI and patients who presented with other etiologies. Patient’s age was compared with the Student’s t-test. Duration of priapism was compared with the Mann-Whitney U test. Categorical data were compared with the chi-square test. The total number of annual emergency room visits at Cedars-Sinai Medical Center were obtained and averaged from 2010 to 2018 to calculate the incidence of priapism at our institution. As the priapism data were only available through the first half of 2018, we adjusted the number of emergency room visits in 2018 by half, as well. Incidence rates over time were tested with Poisson regression. Changes in the proportion of priapism encounters caused by recreational injections across time were tested with logistic regression with post hoc testing adjusted for multiple comparisons. This was done annually and for 3-year intervals. Analysis was performed with SAS 9.2 software (SAS Institute; Cary, NC). Data were considered statistically significant when P < .05.

RESULTS

We identified 169 priapism encounters among 143 unique patients. Priapism at our institution accounted for 21.93 encounters per 100,000 emergency department visits during the years studied and did not vary significantly over time (Poisson regression, P = .214). Based on chart review, all were suspected to be ischemic, except for 2 encounters of stuttering priapism which were excluded from further analysis. Mean age was 45.5 ± 12.1 years. A urologic consult was requested in 130 of the 169 encounters (76.9%). Recreational ICIs were identified by manual chart review and accounted for 82 out of the 169 of priapism encounters (49%). Other etiologies included urologist-prescribed ICIs (25%), oral phosphodiesterase type 5 inhibitors (5%), sickle cell (4%), trazadone (5%), other medication (5%), and unknown (7%). Twenty patients (14%) had 2 or more episodes of priapism in the study period and accounted for 46 of the priapism encounters (27%). Tri-Mix was the injectable used in 77 out of 82 patients in the recreational injection group (94%). The other agents used included Quad-Mix (2), alprostadil (1), phentolamine (1), and unknown (1). Table 1 contains demographic information.

Table 1.

Priapism and patient demographics (143 unique patients with 169 priapism visits)

Demographics	n (%)
Ethnicity
White	103 (72)
Black	21 (15)
Hispanic	10 (7)
Asian	4(3)
Other	5(3)
Priapism etiology
Recreational injectable	82 (49)
Urologist-prescribed injectable	43 (25)
Oral phosphodiesterase type 5 inhibitor	9(5)
Trazadone	9(5)
Other medication	9(5)
Sickle cell	7(4)
Unknown	11 (7)
Urology consulted	130 (76.9)
Spontaneous resolution	25 (14.8)
Corporal irrigation	122 (72.2)
Injection of sympathomimetic	137 (81.1)
Corporal irrigation and injection of sympathomimetic	119 (70.4)
Operative intervention	26 (15.4)
Inpatient admission	31 (18.3)

Spontaneous resolution of the priapism occurred in 25 encounters (14.8%). Corporal aspiration/irrigation alone was used in 4 encounters (2.4%), and injection of vasoactive substance alone was used in 19 encounters (11.4%). Both corporal aspiration/irrigation and injection of a sympathomimetic were used in 119 encounters (70.4%). Operative intervention was required for 26 patients (15.4%), which included a shunt performed either at bedside (8 patients) or in the operating room (18 patients). No implantable penile prostheses were performed for any patient on initial presentation. Table 2 provides a breakdown of the types of operative shunts performed.

Table 2.

Types of shunts performed

Location and type of shunt	No.
Bedside	8
T-shunt	5
Ebbehoj shunt	1
Winter shunt	1
Unspecified	1
Operating room	18
T-shunt	6
Ebbehoj shunt	6
Al-Ghorab shunt	2
Quackle shunt	2
Quackle and Al-Ghorab shunts	2
Total	26

Patients who used recreational injections were younger than those who presented with other etiologies, (43.5 ± 10.2 years vs 47.5 ± 13.5 years; P = .048) and had a delayed presentation (median, 12 hours vs 8 hours; P < .001). There was no statistical difference in the proportion of patients who required an operative intervention in each group (14.6% of recreational ICI users vs 16.1% of all other patients; P = .23).

Table 3 shows the number of priapism encounters caused by recreational injections each year. Over the 9-year period, there was a significant difference in the percent of priapism cases due to recreational injections (logistic regression, global test of trend; P = .0424). Post hoc testing shows that the proportion of recreational injections in 2018 was higher compared to 2011 (80% vs 28.6%; P = .0243), but no other year achieved statistical significance. When the time frame was grouped into 3-year intervals, the proportion of priapism visits caused by recreational ICIs was 38% (23 out of 60) in the first 3 years (2010–2012), 48% (31 out of 64) in the middle 3 years (2013–2015), and 62% (28 out of 45) in the last 3 years (2016–2018). This difference trended toward significance (P = .0563).

Table 3.

Priapism cases due to recreational injections (2010–2018)

Year	Priapism cases, N	Recreational, n (%)
2010	13	4 (30.8)
2011	21	6 (28.6)
2012	26	13 (50.0)
2013	21	12 (57.1)
2014	20	10 (50.0)
2015	23	9 (39.1)
2016	13	10 (76.9)
2017	17	6 (35.3)
2018	15	12 (80.0)

Based on manual chart review, 43 patients (30%) were identified as HIV+. A total of 36 out of 72 patients who used recreational ICIs (50%) were HIV+, and 7 out of 71 patients with other etiologies of priapism (10%) were HIV+. Patients who presented with priapism after recreational ICI use were more likely to be HIV+ compared to patients who presented with other etiologies of priapism (odds ratio, 9.14; 95% CI, 3.69–22.64; P < .001). Seven patients in the recreational injection group (9%) acknowledged or were found to have used methamphetamines or cocaine at the time of the ICI; however, for many patients there was no mention of drug use in the chart, and toxicology screens were not routinely performed.

DISCUSSION

We have described the etiologies and outcomes of priapism at a large Los Angeles tertiary medical center from 2010 to 2018. To our knowledge, this cohort is the largest series of priapism cases described at a single institution. In this 9-year span, almost half of all visits were caused by recreational ICI. The overall incidence of priapism has been estimated at 0.34 to 1.5 per 100,000 person-years in earlier European and Australian cohorts.^7–9 In the United States, Chrouser et al¹⁰ reviewed the Nationwide Inpatient Sample from 1998 to 2006 and found that the rate of inpatient diagnosis of priapism has been increasing over time, despite a relatively constant number of cases caused by sickle cell disease. This has been attributed to pharmaceutical advances in the treatment of erectile dysfunction, as more cases are now caused by iatrogenic etiologies. Stein et al¹¹ reviewed the Nationwide Emergency Department Sample from 2006 to 2009 and found that priapism accounted for 8.05 encounters per 100,000 emergency department visits. The incidence of priapism at our institution is over 2.5 times the national figure, despite a very low incidence of priapism caused by sickle cell disease in our patient population. Although much of this discrepancy can be attributed to recreational ICIs, iatrogenic causes are not insignificant, as 25% of the priapism encounters were due to urologist-prescribed ICIs. In total, nearly three-quarters of all priapism encounters were caused by any form of ICI. This highlights the need for urologists to describe the risks of priapism when prescribing these injections. Importantly, they should also be aware of the risk that their patients may be sharing these injections in the community.

Recreational use and abuse of all erectile dysfunction pharmaceuticals are becoming more prevalent.¹² In our series, recreational injections appear to be an increasingly common cause of priapism. Surveys have shown that up to 21.5% of young, healthy men have taken a phosphodiesterase type 5 inhibitor as a recreational drug.¹³ They are often obtained from a friend or pharmacy without any medical prescription or physician evaluation. These drugs can also be obtained through a variety of online drugstores but are often contaminated with herbal products.¹⁴ Recreational use of intracavernosal injections appears to be a recent phenomenon that has not yet been well described in the literature. Diaz et al¹⁵ presented a series of 57 patients with priapism in Miami Beach, Florida, 36 of whom (57%) had used recreational injections. Similar to our findings, this group also had more delayed presentation and high rates of HIV and illicit drug use.

Recreational injections pose a serious public health risk. Anecdotally, most patients have described getting the injection from a “friend,” but it is unclear how the medication was initially distributed and how the doses are titrated. These patients are not appropriately warned about the risks, side effects, and drug interactions, which can result in serious consequences. In our series, patients with recreational ICI use presented later than those with other etiologies of priapism, increasing their risk of permanent erectile dysfunction. These patients were either unaware of the consequences or unwilling to seek medical attention. In addition, needle sharing for injections may pose another risk, although this information was not present in the medical records we reviewed.

The epidemiology of this practice should also be further investigated. Cedars-Sinai Medical Center is located in the middle of Los Angeles County, immediately adjacent to the city of West Hollywood, where 40% of the population identifies as a sexual minority.¹⁶ It shares a few characteristics with Miami Beach, Florida, where the other series was described by Diaz et al. Both are large, warm-climate, urban/metropolitan cities with a significant amount of tourism and large LGBTQ communities. Our retrospective review was unable to abstract detailed information about the patients’ sexual preferences and practices. In Los Angeles County, men who have sex with men are the primary source of HIV transmission, and an estimated 18.4% of men who have sex with men are HIVþ.¹⁷ The patients who presented with recreational injections clearly represent a higher risk group, as 50% of them were HIV+. Future research should identify the specific patient populations and geographic hotspots that engage in this practice to provide targeted educational efforts. Ultimately, although we were able to identify patients who used recreational injections because they presented with priapism, the true incidence of this practice is unknown.

There are several limitations to this study, including its retrospective design; thus, we were limited by the availability of data in each patient’s medical records. Our single-institution experience may not be representative of the greater Los Angeles area or other metropolitan areas. However, it is our hospital’s unique location that allowed us to detect the frequent occurrence of recreational ICI use. In addition, long-term follow up data were not available for the majority of the patients. Although a similar proportion of patients required an operative intervention in the recreational group and the non-recreational group, it is unclear if the delayed presentation of the recreational group had an impact on their long-term erectile function. Nevertheless, this is an exploratory epidemiological study of a large, modern cohort of patients with priapism. It may reflect new national trends in the causes and incidence of priapism. By describing this series, we aim to increase awareness of a dangerous phenomenon that has significant public health implications.

CONCLUSION

Nearly half of all priapism visits are attributed to recreational use of intracavernosal injections at our institution. Although the short-term outcomes appear to be similar compared to patients who present with other etiologies of priapism, the long-term effects on erectile function are unknown. In addition, this is a high-risk patient population with high rates of HIV and illicit drug use. Further effort should be made to reduce the incidence of recreational injections across the country and to increase public awareness of this harmful practice.