About

➀ Read and Learn

The following course content

Introduction   

Erectile dysfunction (impotence) is a complex condition affecting males over the age of 40, with its incidence rising worldwide and marked by a persistent or recurrent inability to achieve and maintain an erection sufficient for satisfactory sexual activity [1]. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), defines erectile dysfunction (ED) as a condition that persists for a minimum of six months and specifies that the symptoms must be present in at least 75% of sexual encounters and must cause significant distress to the individual [2][3]. 

In the U.S., erectile dysfunction (ED) impacts at least 12 million men [4]. Numerous regulatory mechanisms participate in maintaining normal erectile function with disruptions in any of the penile arteries, nerves, hormone levels, smooth muscle tissue, corporal endothelium, or tunica albuginea—alone or in combination—leading to erectile dysfunction (ED) [5]. ED can arise from vascular, neurological, psychological, and hormonal disorders and often associated with health issues including diabetes mellitus, hypertension, hyperlipidemia, obesity, testosterone deficiency, and treatments for prostate cancer [5]. In addition, certain medications and substances can also trigger or exacerbate ED. Identifying the underlying causes is fundamental for effective treatment. The psychological and emotional impacts of ED are significant, affecting both the individual and their partner. If not addressed, ED can lead to anxiety, depression, reduced self-esteem, and strained interpersonal relationships [5].  

A wide range of treatment options are available for managing ED. These include oral phosphodiesterase type 5 inhibitors, hormone replacement therapies, external vacuum devices, urethral suppositories, intracavernous injections (in the base of the penis), topical gels, surgical interventions, and sex therapy [5][6]. The evaluation and treatment of ED emphasizes the role of an interprofessional team in managing this condition. The revised five-question International Index of Erectile Function provides a quick clinical tool for assessing ED. The goal of this tool is to facilitate the automated scoring of The International Index of Erectile Function (IIEF), also referred to as the SHIM Questionnaire [7][8]. 

Differential Diagnosis 

Erectile dysfunction (ED) is a complex condition with a variety of underlying causes, necessitating a thorough differential diagnosis to tailor treatment. The initial differential diagnoses for ED would be hypogonadism, loss of libido, depression with low mood, and other psychological conditions [5]. ED may be the first manifestation of diabetes or cardiovascular disease, as well as depression [5][8][9]. Differentiating between true erectile dysfunction and other sexual disorders, such as premature ejaculation, is essential and accomplished by obtaining a good sexual history of the patient. 

Differential diagnoses to consider include: 

• Abdominal Vascular Injuries 

• Cirrhosis Imaging 

• Depression 

• Hemochromatosis 

• Hypertension 

• Hypogonadism 

• Hypopituitarism (Panhypopituitarism) 

• Noncoronary Atherosclerosis 

• Peyronie's Disease 

• Scleroderma 

• Sickle Cell Disease (SCD) 

• Type 2 Diabetes Mellitus 

Causes of ED can be categorized into several types: psychological (including performance anxiety, stress, and relationship problems), endocrine (such as hypogonadism, hyperprolactinemia, thyroid disorders, and diabetes mellitus), neurogenic (including spinal cord injuries, multiple sclerosis, Parkinson's disease, stroke, and peripheral neuropathy), and vascular (such as atherosclerosis, hypertension, peripheral artery disease, and heart disease) [8][10][11][87].  

Anatomical causes can include Peyronie’s disease, characterized by a curvature of the penis due to fibrous scar tissue, and congenital penile abnormalities [12]. Medication-related causes often involve antihypertensives (e.g., beta-blockers), antidepressants (SSRIs), antiandrogens used in prostate cancer therapy, diuretics, and antipsychotics [13] [14]. Lifestyle factors include smoking, excessive alcohol consumption, obesity, and a sedentary lifestyle which can play a significant roles, as do surgical or traumatic causes including trauma to the pelvic region or spinal cord [15]. Conducting a thorough history and physical examination, alongside appropriate laboratory tests, is necessary. This approach helps identify the underlying cause of ED, allowing for the most effective treatment plan, addressing any reversible causes, and enhancing overall health outcomes. 

Diagnostic Considerations  

In addition to conditions considered in the differential diagnosis, it is essential to evaluate for other significant health issues that might contribute to erectile dysfunction. These include cancer and its treatments, epilepsy, multiple sclerosis, Guillain-Barré syndrome, Alzheimer's disease, epispadias, widower syndrome (e.g. Takotsubo cardiomyopathy (TCM) – broken heart syndrome), performance anxiety, malnutrition, leukemias, and the effects of various medications such as antidepressants, antipsychotics, antihypertensives, antiulcer drugs, and those used to treat hyperlipidemia [15][16][17]. 

For the diagnosis and management of erectile dysfunction, the Process of Care Model provides a structured approach suitable for primary care and multidisciplinary settings [18][19]. This model includes a rational approach to diagnosis and treatment, emphasizes thorough clinical history taking and a focused physical examination, mandates specialized testing and referrals in specific scenarios, and advocates a stepwise management approach that prioritizes treatment options [19]. It also emphasizes incorporating the needs and preferences of the patient and their partner into the decision-making process. This model encourages patients and their partners to express their preferences for reasonable and appropriate treatment options and collaboratively implement these with their physician. The model is data-driven, evidence-based, and applicable to a wide array of healthcare providers, reflecting contemporary management practices for erectile dysfunction (ED) [19].  

The revised model (2018) emphasizes the modification of risk factors and the correction of comorbidities associated with ED as key components of patient management [19], including positive lifestyle changes, dietary improvements, and increasing physical exercise. First-line medical therapies should accompany these lifestyle modifications, including sexual counseling and therapy, which consider patient sexual dynamics, and pharmacotherapy with phosphodiesterase type 5 inhibitors (PDE5Is) [15].  

The revised model underscores the essential role of healthcare providers in the assessment and treatment of men presenting with erectile dysfunction. According to the model, the initial assessment should comprise a comprehensive clinical history, a targeted physical examination, and specific laboratory tests. Subsequent management should be goal-oriented, considering the needs and preferences of both the patient and their partner [19]. The stepwise treatment algorithm prioritizes criteria such as ease of administration, reversibility, relative invasiveness, and cost. 

Medications that Can Cause Erectile Dysfunction 

Medications and substances that may cause or contribute to erectile dysfunction include a variety of drug classes and substances. Chronic analgesics such as opiates can affect erectile function [94]. ED can also be caused by anticholinergics, tricyclic antidepressants, and anticonvulsants like phenytoin and phenobarbital [20]. Antidepressants, including lithium, monoamine oxidase inhibitors, selective serotonin reuptake inhibitors, and tricyclic antidepressants, may contribute to ED. Antihistamines, such as dimenhydrinate, diphenhydramine, hydroxyzine, meclizine, and promethazine, are known to have similar effects [20][21]. 

Antihypertensives, including alpha blockers, beta blockers, calcium channel blockers, clonidine, methyldopa, and reserpine, can contribute to erectile dysfunction [20][21]. Anti-Parkinson agents including bromocriptine, levodopa, and trihexyphenidyl also play a role. Cardiovascular agents such as digoxin, disopyramide, and gemfibrozil, as well as cytotoxic agents like methotrexate [20][21][91]. Diuretics, including spironolactone and thiazides, can affect erectile function [20][21].  

Hormonal treatments, including 5-alpha reductase inhibitors, corticosteroids, estrogens, luteinizing hormone-releasing hormone agonists, and progesterone, are also contributing factors [20][21]. Illicit drugs, alcohol, and nicotine, including amphetamines, barbiturates, cocaine, heroin, and marijuana can impact erectile function [22]. Immunomodulators such as interferon-alfa and tranquilizers, including benzodiazepines, butyrophenones, and phenothiazines, are known to contribute to erectile dysfunction [20][21][22][23]. 

Medical and Sexual History 

A detailed knowledge of the physiological, neurological, and molecular dimensions of ED is vital for devising effective treatments and for further advancements in our understanding of this condition. Gathering a detailed medical and sexual history is an initial step in diagnosing erectile dysfunction (ED). A health care provider should inquire about numerous aspects including a patient’s confidence in achieving and maintaining an erection, the firmness of their erections suitable for intercourse, their ability to maintain an erection throughout sexual activity, and their overall satisfaction with their sexual experiences. Providers should ask about morning erections, level of sexual desire, frequency of climax or orgasm, and any ejaculatory functions [25]. A comprehensive history will help a provider understand the potential underlying factors of an individual’s ED, revealing any related diseases or treatment side effects and diagnosing issues related to sexual desire, erection, climax, or ejaculation. 

Information about any surgeries or medical treatments that could have impacted nerve or vascular health near the penis is also fundamental [24]. Providers should gather details about any medications, whether prescription or over the counter, as well as the use of substances like illegal drugs, alcohol, or tobacco [22].  

A healthcare professional may also delve into psychological or emotional factors that could contribute to ED by asking personal questions or utilizing a questionnaire. Questions directed to the patient’s sexual partner may help to better understand relationship dynamics that could affect ED.  

Advanced Physical Assessment 

A physical examination can identify physical causes of ED. This includes assessing the sensitivity and appearance of the penis, which can indicate nerve or structural issues, such as those caused by Peyronie’s disease [12]. The examination should explore signs of hormonal imbalances including abnormal hair growth or breast enlargement and check vascular health through blood pressure and pulse measurements in your wrists and ankles [26][27]. The patient’s history should focus on gathering relevant information that might indicate prostate cancer or predisposing factors. Advanced nursing health assessment for prostate cancer is a meticulous process that requires a comprehensive evaluation, which encompasses taking a detailed patient history, conducting a thorough physical examination, and utilizing appropriate diagnostic tests [28]. Key areas include urinary symptoms such as difficulty starting urination, weak urine flow, frequent nocturnal urination, pain during urination, presence of blood in urine or semen, painful ejaculation, and pain in the lower back, hips, or thighs [28].  

A thorough documentation of any family history of prostate cancer or other cancers, as this can increase risk. The medical history should also note any previous cancers, surgeries, or health conditions that might affect prostate health. Questions about lifestyle factors such as diet, physical activity, smoking, and alcohol use are also important, as these can influence the risk of prostate cancer [28]. A provider should palpate the prostate gland (digital rectal exam) through the rectal wall to check for irregularities in size, shape, or texture [37]. A general assessment of the patient’s overall health should include height, weight, height, body mass index (BMI), and visible signs of distress [28]. This comprehensive approach ensures that providers consider all aspects of the patient's health, leading to a more accurate differential diagnosis and effective treatment planning of ED.  

Sexual history questions include inquiries about the quality and duration of erections [29]. Additional questions focus on the duration an erection lasts, whether the penis feels numb or unusual, and if it loses rigidity during foreplay or when attempting vaginal penetration. It is also important to know if the penis stays erect until after penetration, which could indicate anxiety or a venous leak, and if morning erections are still occurring [29]. Questions regarding overnight erections include hardiness and if hardness varies from day to day.  

It is also important to determine if there have been times when erections worked better, such as during masturbation or with an alternate partner, and how erectile rigidity compares during masturbation versus intercourse [29]. The history of normal erections and the onset of erectile troubles is critical. A sudden, unexplained onset of erectile dysfunction is often psychogenic [5]. Further questions address significant life changes that coincided with the start of erection trouble, including new relationships or medications. A history of traumatic sexual events, contraception use, previous treatments, and whether ejaculation and orgasm remain normal despite erection issues, including how hard the erection is at ejaculation [5].  

Other pertinent information can include the patient’s general interest in sexual activity and how often intercourse would be desired if erectile dysfunction were not an issue. The partner's agreement with the frequency, awareness of the treatment-seeking, and willingness to become involved in treatment are also important. Questions should include the straightness or curvature of erections, problems with libido, interest, ejaculation, or orgasm, and the timeline of these symptoms [30].  

Testing 

Laboratory Testing 

Blood tests can help identify underlying conditions that might cause ED, such as diabetes, atherosclerosis, chronic kidney disease, or hormonal imbalances [31]. 

• Complete Blood Count (CBC) - May detect signs of anemia or other blood disorders that might be contributing to ED [35]. 

• Lipid Profile - Used to assess the risk of cardiovascular disease, which can affect blood flow and contribute to ED [36]. 

• Blood Glucose Levels - High glucose levels are indicative of diabetes, which is a common cause of ED due to nerve and blood vessel damage [38]. 

• Serum Creatinine and Kidney Function Tests - These tests evaluate kidney health, which can affect hormonal balances and blood flow, influencing ED. 

• Liver Function Tests - Liver issues can affect hormonal balance, including levels of sex hormones, impacting erectile function [33]. 

• Testosterone Levels - Low testosterone (hypogonadism) can cause or contribute to ED [32]. 

• Thyroid Function Tests - Thyroid hormones regulate metabolism and can influence sexual function, so abnormalities may contribute to ED [34]. 

• Prolactin Levels - Elevated prolactin can indicate pituitary disorders that may lead to ED [39]. 

• PSA (Prostate-Specific Antigen) - Used to screen for prostate issues, including cancer, which can impact sexual function [42]. 

• Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH) - These are additional hormones assessed if there is a suspicion of pituitary or hypothalamic disease [40][41]. 

Imaging Tests 

The cause of ED often involves multiple factors, including physiological and psychological issues. Various conditions, such as neurological and endocrine disorders and medication side effects, may contribute to ED. A thorough medical history and physical exam guide the management of ED, while imaging tests can help determine if there is an obvious underlying physiological causes.  

A penile doppler ultrasound is a noninvasive test that measures blood flow in and out of the penis using high-frequency sound waves to create real-time images [43]. This test helps diagnose and monitor erectile dysfunction (ED), which can result from insufficient blood flow into the penis (inflow ED) or blood becoming trapped in the penis (outflow ED). A technician uses Doppler ultrasound to create color images that show blood speed and direction with a handheld device [43].  

Ultrasonography is an effective imaging technique providing real-time visualization of normal anatomy and significant pathological changes related to erectile dysfunction (ED) [92]. Penile Doppler ultrasonography (PDUS) measures blood flow in the penis during and after an erection, aiding in diagnosing and evaluating ED and distinguishing between vascular and nonvascular causes [92]. 

Color Doppler ultrasonography (CDUS) can assess functional alterations in penile blood flow, such as those occurring in erectile dysfunction (ED) [43]. Color Doppler ultrasonography (CDUS) of the penis is a valuable tool for identifying vasculogenic ED and may also predict coronary vascular disease [43]. 

Additional Tests 

Nocturnal Penile Tumescence (NPT) Test, although not a blood test, measures erections during sleep and can help distinguish between physical and psychological causes of ED [44][45]. Tumescence refers to the state of being swollen. Nocturnal erection tests involve wearing a device around the penis overnight to monitor erections during sleep, helping to determine any physical or psychological factors for ED [45]. 

For more detailed assessments, electronic monitoring devices can record erection firmness, number, and duration. The injection test involves administering medication into the penis or into the urethra to induce an erection, assessing the erection’s fullness and duration to help pinpoint the cause of ED [24]. These tests are critical in guiding healthcare professionals in determining the appropriate interventions for managing ED. 

Pathophysiology  

Various classification systems for erectile dysfunction (ED) are based on different criteria. Classification of ED can be based on its underlying causes, such as diabetic, iatrogenic (caused by medical treatment), or traumatic origins [5]. Other classifications focus on the neurovascular mechanisms that play a role in the erectile process, dividing ED into categories like failure to initiate (neurogenic), failure to fill (arterial), or failure to store (venous) blood [46]. 

Hemodynamics and Mechanism of Erection and Detumescence  

The smooth muscles within the corpora cavernosa, along with the smooth muscles of arteriolar and arterial walls, play a critical role in the erection process [47]. These muscles remain contracted in a flaccid state, allowing minimal arterial flow for nutritional purposes [47]. Upon sexual arousal, neurotransmitters released from cavernous nerve terminals induce muscle relaxation, resulting in increased arterial blood flow and arteriolar dilation [47]. This influx of blood expands the sinusoids, trapping blood and compressing the venular plexuses, thereby reducing venous outflow [47][48]. The stretching of the tunica albuginea further decreases venous outflow by occluding emissary veins, which increases intracavernous pressure and elevates the penis into an erect position [47][48]. Subsequent muscle contractions may enhance erection rigidity, influenced by the penis's size and anatomical attachments. 

The dynamics in the corpus spongiosum and glans penis differ from those in the corpora cavernosa [48]. During erection, these areas experience less venous occlusion due to their thinner tunica coverage, functioning similar to an arteriovenous shunt during peak erection [48]. This mechanism contributes to the engorgement and pressure in the glans and spongiosum. 

Neuroanatomy and Neurophysiology of Penile Erection 

The triggers of penile erection in humans include auditory, visual, olfactory, tactile, and imaginative stimuli with reflexogenic and psychogenic stimuli acting through the sacral parasympathetic routes [66][67]. Multiple sites within the brain and spinal cord, along with the coordination of somatic and autonomic pathways, make sexual behavior, including erection, vulnerable to neurological injury and disease [66]. The brain and spinal cord work together to process, coordinate, and distribute the neural inputs necessary for sexual behavior, including erection [66]. Activation of neurons in certain regions, either pharmacologic or through electrical stimulation, links to penile tumescence [67]. 

Peripheral and autonomic pathways innervate the penis, which integrate signals from the spinal cord and peripheral ganglia to regulate neurovascular events during erection and detumescence [47]. Both sympathetic and parasympathetic autonomic nerves, along with somatic sensory and motor nerves, play crucial roles in this regulatory process [47]. 

In males, physiological sexual arousal begins with an erection, initiated by sensorial signals transmitted by the dorsal nerve of the penis after stimulation of nerve endings along the penis and glans [67]. Penile hemodynamics during erection involve the swelling of the cavernous bodies due to vasodilation, caused by nitric oxide released by the endothelium following parasympathetic stimulation of the pelvic nerves [49][67]. The pelvic, cavernous, and pudendal nerves of the sympathetic nervous system, along with various vasoconstrictor factors mediate detumescence (subsidence of a swelling) [67].  

Molecular and Clinical Understanding of Erectile Function 

Advances in molecular biology and clinical research have enhanced the understanding of erectile function, emphasizing the role of nitric oxide and the relaxation of intracavernous smooth muscle [49]. This relaxation is important for increasing blood flow and reducing venous outflow, both essential for maintaining an erection [49]. Ongoing research into the pathways regulating smooth muscle relaxation and contraction continues to contribute to the development of therapeutic strategies for treating erectile dysfunction (ED). 

Statistical Evidence / Etiology 

Erectile dysfunction (ED) often arises from multifactorial causes. It is important to distinguish whether the condition stems from psychological factors or has an organic basis. The 1994 Massachusetts Male Aging Study (MMAS) found that 52% of men experience some degree of ED, with 10% being impotent [50]. Medication-related ED occurs in 25% of cases due to blood pressure medications [14]. Vascular disease is the leading cause of natural ED, with 35% to 75% of men with diabetes also suffering from ED [38]. Up to 40% of men with renal failure and 30% of men with chronic obstructive pulmonary disease (COPD) have ED [51]. Smoking and illicit drug use are more prevalent among younger men with ED [27][30]. Obesity and diabetes account for 8 million cases of ED, and the majority (79%) of men with ED are overweight [52]. 40% of men with ED also have hypertension, and 35% of men with hypertension experience ED [5]. In addition, 42% of men with ED suffer from hyperlipidemia [5].  

Undiagnosed diabetes (28%) in three times as common in men with ED when compared to men without ED (10%) [53]. Among men over 50, those with diabetes have twice the risk of ED (46%) compared to those without diabetes (24%), with the risk increasing with the duration and severity of diabetes [52][54]. Furthermore, one-third of diabetic men experience hypogonadism, a condition linked to ED [52][54]. Up to 35% of men with ED also suffer from hypogonadism, and about 6% have abnormal thyroid function [34]. While testosterone deficiency can affect erectile function, vascular disease and diabetes are much more common causes of ED [32][52][54].  

Obesity increases ED risk by 50% compared to men of normal weight, and one-third of obese men with ED who join a weight loss program see their symptoms resolve within two years. [15]. Bariatric surgery for obesity can improve sexual performance [58]. Smokers who quit experience a 25% improvement in erectile quality after one year [55]. Heavy alcohol use also increases the risk of ED due to direct toxicity to the corporal endothelium, loss of smooth muscle tissue, and early neuropathy [5].  

There is a strong correlation between benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS) and ED, with up to 72% of men with symptomatic BPH also experiencing ED [56]. Men with depression have a 40% higher chance of having ED, and those with ED have three times the chance of being depressed [57]. In addition, 30% to 60% of men with ED experience premature ejaculation [59].  

Worldwide, experts project the prevalence of ED to rise to 322 million men by 2025 [60]. In the United States, about 30 million men experience ED, and estimates show that 1 in 10 men will face ED at some point in their lives [61]. In an international study, the U.S. reported the highest self-reported rate of ED at 22%, while Spain reported the lowest at 10% [62]. 

Cardiovascular Disease and Erectile Dysfunction 

Erectile dysfunction (ED) is an early sign of cardiovascular disease [63]. Therefore, healthcare providers should assess men with ED for cardiovascular risk factors to prevent future major adverse cardiovascular events (MACE) [63]. Studies show that 50% of men with diagnosed coronary artery disease have ED [63]. The similarity in size between coronary and penile cavernosal arteries means that atherosclerosis in the penile arteries precedes coronary artery symptoms, making ED a potential indicator of cardiovascular issues [5]. Patients with ED can exhibit subclinical atherosclerosis for up to a decade before any overt cardiac symptoms [64]. Younger men with unexplained ED have an up to 50-fold increase in cardiovascular risk later in life compared to age-matched controls [65]. 

Traditional risk factors are not present in all individuals at high cardiovascular risk, as a considerable proportion of MACE occurs in men who appear free of risk factors [68]. In men with ED, it is important to consider both traditional and unconventional risk factors. Several parameters from a thorough clinical assessment of men with ED have proven to be valuable predictors of MACE [65]. These include family history of cardiometabolic events, alcohol abuse, fatherhood, decreased partner’s sexual interest, severe impairment in erection during intercourse or masturbation, impaired fasting glucose, increased triglycerides, obesity even without metabolic complications, decreased penile blood flow, or impaired response to an intra-cavernosal injection test [5][65]. Recognizing these risk factors can help identify men with ED who may benefit from a stricter lifestyle or pharmacological interventions to minimize their cardiovascular risk. Addressing these risk factors in men with ED who face elevated risk reduces cardiovascular risk and improves erectile function. 

Impact of Prostate Cancer Treatment on ED 

Post-operative ED is common in prostate cancer patients, with different treatments having varying impacts. Up to 85% of patients undergoing radical prostatectomy may experience ED, compared to a 25% rate in those receiving definitive radiation therapy [68]. Since the cavernous nerves responsible for erection can take 18 to 24 months to heal after radical prostatectomy (RP), natural erections through sexual stimulation and nocturnal erections may be absent during this recovery period [68]. Under normal physiologic function, erections pull oxygen-rich blood into the penile tissue, maintaining its health. Men who cannot achieve natural erections post-RP do not oxygenate their penile tissue, which can lead to atrophy and permanent structural changes [69]. This may result in venous leak, which is irreversible and causes erectile dysfunction [69]. Innovations in surgical techniques, such as nerve-sparing procedures, have lowered the incidence of post-operative ED. 

Controversial Role of Cycling 

The impact of cycling on ED remains debated. Traditional racing bicycle seats may exert considerable pressure on perineal nerves and blood vessels, contributing to ED [70]. A meta-analysis indicated a significantly higher risk of ED among cyclists compared to non-cycling controls [71]. A comprehensive understanding of the multifactorial nature of ED aids clinicians in delivering effective treatment and reassurance to patients, allowing them to address both psychological and organic components. 

Pharmacotherapy & Mechanical Treatments 

Initial treatment for erectile dysfunction (ED) focuses on enhancing overall health through lifestyle modifications, which not only improve erectile function but also reduce cardiovascular risk. Select each treatment based on its specific applications, benefits, potential side effects, and the patient's needs, preferences, and medical history. Proper education on the use and potential risks of these therapies is crucial to ensure safety and effectiveness.  

Lifestyle Changes 

Recommended lifestyle changes include increasing physical activity, adopting a Mediterranean diet or seeking nutritional counseling, and quitting smoking, drugs, and excessive alcohol consumption [15]. Healthcare providers should review and adjust the patient’s medication regimen to eliminate or reduce the impact of drugs that may cause or worsen ED. 

Supplements 

Pharmacological treatments for erectile dysfunction (ED) offer effective options for improving sexual function and quality of life in affected men. L-arginine, an amino acid supplement, is essential for producing nitric oxide synthase, which generates nitric oxide—a key molecule in erectile function. Supplementation with L-arginine (1500 mg to 5000 mg daily) has shown some effectiveness in treating mild to moderate ED by boosting nitric oxide synthase levels [5][49][67].  

Topical Gels 

Eroxon, a proprietary topical gel, is the only over-the-counter product with FDA endorsement for treating ED. The De Novo medical devices classification approved Eroxon on June 13, 2023 [72]. It is the first over the counter treatment for ED in the U.S. that does not require a doctor's prescription [72]. It contains ingredients such as carbomer, ethanol, glycerin, propylene glycol, and potassium hydroxide. Application of the gel to the glans penis provides a cooling effect that stimulates nerve endings and warms the tissue, thereby enhancing blood flow and relaxing the smooth muscles in the corpora cavernosa. This aids in achieving and maintaining an erection. Eroxon has shown a 60% success rate within 10 minutes of application, increasing to 75% after 20 minutes, which is comparable to the efficacy of prescribed oral agents [5]. Eroxon gel is available in the United Kingdom and Belgium, with its release in the U.S. pending.  

Oral Medications 

Oral PDE-5 inhibitors, such as sildenafil, tadalafil, vardenafil, and avanafil, are the first-line treatment for ED due to their effectiveness across various causes including cardiovascular disease, diabetes, and hypertension [73]. Tadalafil offers a theoretical benefit over sildenafil due to its longer half-life and pharmacokinetics, but there is insufficient data to make any formal recommendation [5]. These drugs work by enhancing the relaxation of cavernosal smooth muscle through the prolongation of cyclic GMP effects [73]. These medications require sexual stimulation to work. While PDE-5 inhibitors are effective, they can cause side effects such as headaches, nasal congestion, and visual disturbances [73]. Rare but serious side effects include non-arteritic anterior ischemic optic neuropathy (NAION), which can lead to permanent vision loss, and sudden hearing loss [74].  

Patients who do not respond to one PDE-5 inhibitor may benefit from trying another, as differences in drug metabolism and patient response can influence effectiveness. For those who fail initial PDE-5 inhibitor therapy and have not had their testosterone levels checked, assessing, and treating hypogonadism with testosterone supplementation may be beneficial in conjunction with continued PDE-5 inhibitor therapy [75]. 

PDE-5 inhibitors work by enhancing the effects of nitric oxide, a natural chemical produced by your body that relaxes muscles in the penis [5][49][67][75]. This relaxation increases blood flow, enabling you to achieve an erection in response to sexual stimulation. It is important to note that for patients taking a PDE-5 inhibitor; sexual stimulation is necessary to release nitric oxide from your penile nerves. PDE-5 inhibitors amplify signals, facilitating normal penile function in some individuals. The medications differ in dosage, duration of action, and potential side effects. Common side effects include flushing, nasal congestion, headache, visual changes, backache, and stomach upset [76].  

External Vacuum Devices 

External vacuum devices provide a non-surgical treatment option. These devices use negative pressure to engorge the penis with blood, and a constriction band maintains the erection [77]. They are effective but require practice for optimal use. A penis pump (vacuum erection device) is a hollow tube with a hand-powered or battery-powered pump. Patients place the tube over the penis, then use the pump to remove the air inside the tube. This creates a vacuum that pulls blood into the penis. Once the patient receives an erection, individuals place a tension ring around the base of the penis to hold in the blood and keep it firm. Bruising of the penis may occur, and the band will restrict ejaculation [78].  

Intraurethral and Intracavernous Therapies 

Intraurethral and intracavernous therapies offer alternatives when oral medications are insufficient. Intraurethral prostaglandin E1 (alprostadil) pellets and intracavernous injections of agents like prostaglandin E1 or combination therapies (TriMix or QuadMix) can induce an erection by enhancing smooth muscle relaxation and blood flow within the penis [79]. This method involves using a fine needle to inject alprostadil (Caverject, Edex) into the base or side of the penis [79]. These combination medications, known as bimix when they include two medications and trimix when they include three, treat ED. Administer each injection to create an erection lasting no longer than an hour. Side effects include mild bleeding from the injection, prolonged erection (priapism), and the formation of fibrous tissue at the injection site [79]. 

Alprostadil intraurethral therapy involves placing a tiny alprostadil suppository inside your penile urethra [80]. A special applicator inserts the suppository into the urethra. The erection starts within 10 minutes and, when effective, lasts between 30 and 60 minutes. Side effects can include a burning sensation in the penis, minor bleeding in the urethra, and the formation of fibrous tissue inside the penis [80]. 

Penile Implants 

Penile implants involve placing devices into both sides of the penis. These implants consist of either inflatable or malleable (bendable) rods [81]. Inflatable devices allow you to control when and how long you have an erection, while the malleable rods keep your penis firm but bendable. Healthcare professionals should try other methods before considering penile implants [81]. However, implants have a high degree of satisfaction among those who have tried and failed more conservative therapies.  

Surgeries 

Surgeons perform penile revascularization on a small subgroup of patients, estimated at 5% of all ED cases. [5]. Consideration for this procedure includes younger patients (under 30) with ED following pelvic or perineal trauma that results in an isolated vascular injury [37]. Penile doppler ultrasound and a formal arteriogram must demonstrate arterial insufficiency [5]. The revascularization operation involves anastomosing the inferior epigastric artery to the dorsal artery of the penis or directly to the corpus cavernosum, though long-term results are marginal [5]. 

Surgeons perform arterial balloon angioplasty for focal arterial stenosis of the pudendal (supply blood to the main organs of the pelvic area) or penile arteries [82]. However, the improvement does not last due to arterial narrowing and restenosis unless using drug-eluting stents [82]. This therapy is not yet the standard of care and is helpful in patients with focal, identifiable arterial stenosis in vessels large enough to accept a stent. 

Venous ligation surgery for veno-occlusive dysfunction involves embolizing or ligating the penile veins, such as the deep dorsal vein [83]. Long-term results do not show lasting efficacy [83]. 

Shockwave Therapy 

Low-intensity shockwave therapy has shown efficacy in patients with severe ED not responding to PDE-5 inhibitors [84]. Its presumed mechanism of action includes improved cavernosal hemodynamics, induction of endothelial cell proliferation, and activation of endogenous stem cells, as well as penile revascularization [84][86]. Shockwave therapy increases angiogenic factors that promote neovascularization, restore smooth muscle activity, and attract stem cells [84][85]. This therapy also increases vascular endothelial growth factor, neuronal nitric oxide synthase, and other natural bioactive agents [84][85] [86]. Although the exact mechanism of shockwave therapy remains unclear, its effect is dose-dependent, with 3000 pulses per session yielding better results than 1500 or 2000 pulses [86]. 

Stem Cells and Plasma 

Intracavernous stem cells and platelet-rich plasma therapy are promising but experimental and require more investigation.  

Rehabilitation and Combination Therapies 

Several studies are examining penile rehabilitation therapy after radical prostatectomy surgery, suggesting a benefit, but there is no consensus on the exact treatment selection, duration, or timing [5][87]. The majority of published studies suggest that a combination of PDE-5 inhibitors with external vacuum device therapy offers the best results, although intraurethral pellet therapy and intracavernous injections have been successful [89]. Patients should begin penile rehabilitation treatment early, continuing for up to one year after surgery, though the exact timing lacks study [90]. 

The most effective treatment options for erectile dysfunction in spinal cord injury patients are phosphodiesterase 5-inhibitors and intracavernous drug injections [88]. The choice of treatment should consider factors such as residual erectile function, the location of the spinal cord injury, and the patient's comorbidities.  

Conclusion

Erectile dysfunction (ED) affects men of all ages, with higher prevalence in those over 40 [4]. Men in their 40s have a 40% chance of experiencing ED, and this likelihood increases by about 10% each subsequent decade [93]. The prevalence of ED is rising with at least 12 million men in the U.S. affected [4]. The causes of ED are diverse, encompassing psychological, neurological, hormonal, vascular, and lifestyle factors [8][10][11][87]. Common associated conditions include diabetes mellitus, hypertension, hyperlipidemia, obesity, and testosterone deficiency [5]. Identifying the underlying causes is crucial for effective treatment.  

The psychological and emotional impacts of ED are significant, affecting both individuals and their partners [5]. If not addressed, ED can lead to anxiety, depression, reduced self-esteem, and strained interpersonal relationships. Various treatment options are available, ranging from lifestyle modifications and first-line medical therapies, such as PDE-5 inhibitors, to more invasive options like penile implants and intracavernous injections [15][73]. Providers should tailor treatments to the patient's specific needs, preferences, and medical history, with a focus on safety and effectiveness. 

The Process of Care Model for ED management underscores the importance of a structured, stepwise approach to diagnosis and treatment. It emphasizes the role of healthcare providers in guiding patients through lifestyle changes, psychosexual counseling, and appropriate pharmacotherapy. By adopting this comprehensive model, healthcare professionals can address both the physiological and psychological aspects of ED, improving overall health outcomes and patient satisfaction. 

When evaluating and treating erectile dysfunction (ED), it is important to inquire about sexual health in all adult patients using a non-threatening and non-judgmental approach. Clues to psychological causes of ED include a sudden onset of symptoms, high variability in erectile function, good morning erections, and good erections with masturbation or alternate partners [5]. Refer psychogenic sexual disorders to appropriate mental health providers. 

There is no specific testing for ED, but blood panels including morning testosterone level, CBC, CMP, liver and renal function tests, lipid panel, HgbA1c, and TSH are reasonable. A thorough understanding of the multifactorial nature of ED, combined with a structured approach to diagnosis and treatment, can significantly enhance the quality of care for men with ED. This approach not only improves erectile function but also addresses associated comorbidities and psychological impacts, leading to better overall health and quality of life for patients. 

Conclusion

Erectile dysfunction (ED) affects men of all ages, with higher prevalence in those over 40 [4]. Men in their 40s have a 40% chance of experiencing ED, and this likelihood increases by about 10% each subsequent decade [93]. The prevalence of ED is rising with at least 12 million men in the U.S. affected [4]. The causes of ED are diverse, encompassing psychological, neurological, hormonal, vascular, and lifestyle factors [8][10][11][87]. Common associated conditions include diabetes mellitus, hypertension, hyperlipidemia, obesity, and testosterone deficiency [5]. Identifying the underlying causes is crucial for effective treatment.  

The psychological and emotional impacts of ED are significant, affecting both individuals and their partners [5]. If not addressed, ED can lead to anxiety, depression, reduced self-esteem, and strained interpersonal relationships. Various treatment options are available, ranging from lifestyle modifications and first-line medical therapies, such as PDE-5 inhibitors, to more invasive options like penile implants and intracavernous injections [15][73]. Providers should tailor treatments to the patient’s specific needs, preferences, and medical history, with a focus on safety and effectiveness. 

The Process of Care Model for ED management underscores the importance of a structured, stepwise approach to diagnosis and treatment. It emphasizes the role of healthcare providers in guiding patients through lifestyle changes, psychosexual counseling, and appropriate pharmacotherapy. By adopting this comprehensive model, healthcare professionals can address both the physiological and psychological aspects of ED, improving overall health outcomes and patient satisfaction. 

When evaluating and treating erectile dysfunction (ED), it is important to inquire about sexual health in all adult patients using a non-threatening and non-judgmental approach. Clues to psychological causes of ED include a sudden onset of symptoms, high variability in erectile function, good morning erections, and good erections with masturbation or alternate partners [5]. Refer psychogenic sexual disorders to appropriate mental health providers. 

There is no specific testing for ED, but blood panels including morning testosterone level, CBC, CMP, liver and renal function tests, lipid panel, HgbA1c, and TSH are reasonable. A thorough understanding of the multifactorial nature of ED, combined with a structured approach to diagnosis and treatment, can significantly enhance the quality of care for men with ED. This approach not only improves erectile function but also addresses associated comorbidities and psychological impacts, leading to better overall health and quality of life for patients. 

➁ Complete Survey

Give us your thoughts and feedback

➂ Click Complete

To receive your certificate