Erection is a neurovascular event that involves spinal and supra spinal pathways. The final common pathway involves the release of nitric oxide (NO) from both endothelial cells and neurons, which acts as a vasodilator causing penile engorgement and erection. NO is degraded by the enzyme phosphodiesterase (PDE) type 5 in the penis. Erectile dysfunction (ED), defined as the persistent inability to achieve and/or maintain an erection sufficient for satisfactory sexual performance, results when the neurovascular pathway is interrupted by medical conditions or drugs. A 15-item self-administered questionnaire, the International Index of Erectile Function (IIEF), is one of the most useful tools to evaluate erectile function (EF) in clinical trials, although of much less use in routine clinical practice. The MMAS (Massachusetts Male Aging Study) was the first major epidemiological investigation to study the prevalence of ED. The study found that ED was three times more common in patients with diabetes mellitus. The aetiopathogenesis of ED in diabetes is multifactorial, with vascular and neural factors being equally implicated. Hyperglycaemia is believed to give rise to biochemical perturbations that lead to these microvascular changes. In the MMAS, ED in diabetes was strongly correlated with glycaemic control, duration of disease and diabetic complications. The incidence increased with increasing age, duration of diabetes and deteriorating metabolic control, and was higher in individuals with type 2 diabetes than those with type 1.ED in men with diabetes often affects their quality of life and, as patients are often reluctant to come forward with their symptoms, a carefully taken history is one of the most useful approaches in identifying affected individuals. The PDE inhibitors have revolutionised the management of ED and oral drug therapy is currently first-line therapy for the condition. These agents act by potentiating the action of intracavernosal NO, thereby leading to a more sustained erection. Sildenafil was the first PDE5 inhibitor to undergo evaluation and has been studied extensively. More recently two other agents, vardenafil and tadalafil, have been introduced. All the drugs have been shown to be effective across a wide range of aetiologies of ED, including diabetes. The drugs have been shown to improve EF domain scores, penetration and maintenance of erection, resulting in more successful intercourse. Their effects are greater at higher doses. Sildenafil and vardenafil are shorter-acting agents, while tadalafil has a longer half-life allowing the user more flexibility in sexual activity. Common adverse effects include headache, nasal congestion and dyspepsia, all actions related to inhibition of PDE5. The drugs are generally well tolerated and withdrawal from the clinical studies as a result of drug-related adverse effects were rare. The use of PDE5 inhibitors in the presence of oral nitrates is absolutely contraindicated. The clinical studies to date have not evaluated the use of one drug in the case of treatment failure with another agent. Sublingual apomorphine, which stimulates central neurogenic pathways, is a new agent and may be a suitable alternative in those patients in whom PDE5 inhibitors are ineffective or contraindicated. In clinical trials, all IIEF domains except sexual desire were found to have improved after apomorphine. The median times to erection in these studies were 18.9 and 18.8 minutes for the 2 and 3mg doses, respectively. Intraurethral and intracavernosal alprostadil may be a useful alternative when oral drug therapy is ineffective or contraindicated. The management of ED in the diabetic patient may often involve a multidisciplinary approach where psychosexual counselling and specialist urologist advice is required in addition to the skills and expertise of the diabetologist. Finally, the introduction of the new oral agents have completely revolutionised the management of ED and allowed more individuals to come forward for treatment.
Guidelines recommend that phosphodiesterase type 5 (PDE5) inhibitors are the first-line drug for the treatment of ED (Table 1). Sildenafil citrate was the first oral drug approved for ED in the US.59 The newer PDE5 inhibitors include vardenafil, tadalafil and avanafil. The inhibition of PDE5 enhances cyclic guanosine monophosphate (cGMP)-NO-mediated vasodilatation by preventing PDE5 catabolism of cGMP and so delaying detumescence. PDE5 inhibitors increase the number and duration of erections, as well as the percentage of successful sexual intercourse.60

Crossref | PubMed | Scopus (539) | Google ScholarSee all References Sleep studies in 175 patients with hypertension and erectile problems showed significantly lower penile rigidity measured by strain gauge plethysmography compared with 110 normotensive male controls with similar subjective erectile problems.33x33Hirshkowitz, M, Karacan, I, Gurakar, A, and Williams, RL. Hypertension, erectile dysfunction, and occult sleep apnea. Sleep. 1989; 12: 223–232


This disparity is due not only to the setting in which the patients were accrued, but also to the manner in which they were questioned, because data in the Italian study were collected by the medical staff during subjects' visits for medical care, which might have also affected reporting rates. De Berardis et al.6 used a fairly generalizable cohort of 1,460 Italian men with type 2 diabetes accrued from 114 outpatient clinics and patient lists of 112 general practitioners. However, unlike the other Italian study, they used self-administered, validated questionnaires to assess the prevalence of ED among diabetic men. They found that 34% reported frequent erectile problems, and 24% reported moderate problems, for an overall prevalence of 58%. Depending on how one wishes to define “clinically significant” ED, this is probably a fairly accurate assessment.
Your choice of blood pressure medications could make a difference in the bedroom (or wherever you like to have sex). Thiazides (diuretics or “water pills”) and beta blockers are the most likely to cause erectile dysfunction (ED), while alpha blockers the least likely. Alpha blockers work by reducing nerve impulses to blood vessels, allowing blood to pass more easily. Ask your doctor whether these or other blood pressure medications are best for you.
When it comes to boosting sexual performance, many men will walk all over God’s green earth looking for ways to maintain a good sex life. Luckily men, all you have to do is walk — not run — 2 miles a day. This, along with other healthier lifestyle interventions can help obese men reduce their risk of ED, or even “reverse” current impotence, according to a 2005 study. This comes of importance, since maintaining a trim waistline is a good defense for ED, as men with a 42-inch waist are 50 percent more likely to have ED than those with a 32-inch waist. Getting to a healthy weight and maintaining it is a good strategy for preventing and treating ED.
Crossref | PubMed | Scopus (53) | Google ScholarSee all References A study of 24 patients with ED and untreated essential hypertension showed decreased levels of free and total serum testosterone compared with normal controls.31x31Hughes, GS, Mathur, RS, and Margolius, HS. Sex steroid hormones are altered in essential hypertension. J Hypertens. 1989; 7: 181–187

Since time immemorial, TCM has been adopted by many cultures and is widely practiced in Asian countries despite paucity of level 1 clinical evidence and limited published safety records. TCM is more congruent with Asian values, beliefs and philosophical orientation to health, simple administration, readily available and ease of access or procurement, and general belief that TCM is safer. While Asian males are clearly different from their Western counterparts with respect to biology, culture and beliefs, the practice of TCM appears to be adopted by many Western nations lately. Many men seek TCM to avoid embarrassing visits to physicians and potential side effects of pharmaceutical drugs, or after becoming frustrated with the outcome of modern medicine. Patients are choosing to take more responsibility for their health by exploring a variety of non-pharmaceutical drugs and wellness practices. Furthermore, TCM such as herbal medicine does not address a specific organ system only and is meant to restore and realign the vital energy within the body, which is responsible for ageing, clinical diseases and the deterioration of bodily function; while in Western medicine, each pill is intended for a specific organ/system and that a patient may need a collection of pills to treat multiple comorbidities, rendering modern medicine less attractive to TCM.
Another risk factor is that men with type 2 diabetes may produce less than normal amounts of testosterone, a condition called hypogonadism. A 2007 study found that one-third of men with type 2 diabetes had low testosterone levels. Those men were also more likely to have ED, though the link may have to do with weight, not diabetes per se. Being overweight or obese is a risk factor for hypogonadism.
Erectile dysfunction (ED), or impotence, is when a man has difficulty getting or maintaining a strong enough erection for sexual intercourse or other sexual activity. It can be caused by stress, anxiety or excessive alcohol consumption. But it can also be a symptom of an underlying condition such as atherosclerosis (narrowing of the arteries), diabetes or high blood pressure. Some medications can cause erectile dysfunction, for example beta-blockers and diuretics (commonly used to treat a variety of heart-related conditions such as high blood pressure and heart failure).

Crossref | PubMed | Scopus (72) | Google ScholarSee all References This study found that the mean PSV was a better predictor of the presence of cardiovascular disease than stratification by standard cardiac risk factors such as diabetes mellitus, hypertension, obesity, and smoking. The researchers recommended that persons with no history of prior perineal trauma and with a PSV lower than 35 mL/s should undergo exercise testing before receiving treatment of ED because these patients had a 42% risk of having ischemic heart disease. However, other investigators questioned the utility of using penile arterial flow to predict the presence of ischemic heart disease.18x18Chiu, AW, Chen, KK, Chen, MT, Chang, LS, and Chang, MS. Penile brachial index in impotent patients with coronary artery disease. Eur Urol. 1991; 19: 213–216
Gutiérrez-González, Enrique; Castelló, Adela; Fernández-Navarro, Pablo; Castaño-Vinyals, Gemma; Llorca, Javier; Salas-Trejo, Dolores; Salcedo-Bellido, Inmaculada; Aragonés, Nuria; Fernández-Tardón, Guillermo; Alguacil, Juan; Gracia-Lavedan, Esther; García-Esquinas, Esther; Gómez-Acebo, Inés; Amiano, Pilar; Romaguera, Dora; Kogevinas, Manolis; Pollán, Marina; Pérez-Gómez, Beatriz. “Dietary Zinc and Risk of Prostate Cancer in Spain: MCC-Spain Study.” Nutrients. Jan 2019, 11(1).
Nebivolol seems to have an advantage over other beta-blockers when used to treat men with hypertension and ED. It has additional vasodilating effects because it stimulates endothelial release of nitric oxide (NO), resulting in relaxation of smooth muscle in the corpus cavernosum, allowing penile erection.25 Despite limited studies, nebivolol does not seem to worsen erectile function and some studies have demonstrated significant improvement in erectile function with nebivolol compared with second-generation cardioselective beta-blockers.23,26–28

Erectile dysfunction carries an independent risk for cardiovascular events. A considerable number of studies have examined the ability of ED to predict the risk of future fatal and non-fatal cardiovascular events (myocardial infarction, stroke, revascularization) and total mortality in the general population and in high CV risk patients, in diabetics and in heart failure patients.5,19–22 In a meta-analysis of 14 prospective cohort studies involving 92 757 men followed for a mean period of 6.1 years (Figure 4), ED increased significantly and independently of traditional risk factors the risk of CV events, CV mortality, myocardial infarction, cerebrovascular events, and all-cause mortality by 44, 19, 62, 39, and 25% respectively.5 This predictive ability also extends in men with known CVD: ED increased the risk of all-cause mortality by 90%.5 Of importance, the predictive ability of ED is higher in younger ED patients5 despite the fact that probability of ED increases with age, most likely identifying a group of patients with early and aggressive vascular disease.23 Clinical implementation of ED as a biomarker relies on whether its addition on classical risk scores such as the Systematic COronary Risk Evaluation (SCORE) or the Framingham correctly reclassifies a meaningful percentage of patients into a higher or lower risk category. To this end, data are limited. Yet, in a population-based study of men 40–70 years of age, the addition of the ED status to the Framingham risk score resulted in a reclassification of 6.4% of low-risk patients to intermediate risk.19
The body’s source for nitric oxide production is the amino acid L-arginine, which is naturally found in many foods. The average American ingests about 3,000–5,000 mg of L-arginine per day, as it is an amino acid naturally contained in many foods. Meats of all varieties, nuts, and dairy products are rich in L-arginine, so the body is accustomed to intake levels of several thousand milligrams every day.

medicines called alpha-blockers such as Hytrin (terazosin
HCl), Flomax (tamsulosin HCl), Cardura (doxazosin
mesylate), Minipress (prazosin HCl), Uroxatral (alfuzosin HCl),
 Jalyn (dutasteride and tamsulosin HCl), or Rapaflo (silodosin).
Alpha-blockers are sometimes prescribed for prostate
problems or high blood pressure. In some patients, the use
of Sildenafil with alpha-blockers can lead to a drop in blood pressure or to fainting
If you have been diagnosed with heart disease or have already had a heart attack and are experiencing erectile dysfunction, it is critical that you discuss erectile dysfunction medication with your physician before considering taking it. Popular erectile dysfunction medications such as Viagra (sildenafil), Cialis (tadalafil) and Levitra (vardenafil) can interact with a range of cardiovascular disease medications. Interactions are possible with blood pressure medications; blood thinners such as Coumadin (warfarin), nitrates for the treatment of chest pain, and antiarrhythmia medication for the treatment of irregular heart rhythms.

In another study from ExCEED, Penson et al.38 compared erectile function and disease-specific quality of life of men with ED and diabetes to those of men with ED without diabetes. They found that those with diabetes reported significantly worse erectile function (P = 0.004) and intercourse satisfaction (P = 0.04) than those without diabetes. Importantly, the diabetic patients also reported that ED had a significantly worse psychological impact on their overall emotional life than did their nondiabetic counterparts (P = 0.01). Interestingly, no differences were noted between the two groups in the psychological impact of ED on the sexual experience.


Gene therapy has the potential to become a future management option for patients with CAD and ED. Animal studies have been conducted to evaluate the effects of gene therapy. A rat model was studied by Bivalacqua et al. to evaluate the effect of the combination of eNOS gene therapy and sildenafil. This research suggested that erectile response was greater in male rats with diabetes treated with combination eNOS gene therapy and sildenafil, compared with male rats with diabetes treated with eNOS gene therapy or sildenafil alone.76–78
The recommended dosage of sildenafil is 50 mg/day, usually taken 1 hour before sexual activity. This dose may be increased to 100 mg or decreased to 25 mg based on side effects.6 PDE5 inhibitors also have a beneficial effect in the treatment of heart failure with reduced ejection fraction as well as pre- and post-capillary pulmonary hypertension. The use of PDE5 inhibitors in the treatment of right heart failure and left ventricular failure associated with combined pre- and post-capillary pulmonary hypertension has been well studied.71,72

Abstract | Full Text | Full Text PDF | PubMed | Scopus (395) | Google ScholarSee all References Sildenafil has no effect on bleeding time or prothrombin time when used either alone or in patients taking aspirin or warfarin.61x61Nehra, A, Colreavy, F, Khandheria, BK, and Chandrasekaran, K. Sildenafil citrate, a selective phosphodiesterase type 5 inhibitor: urologic and cardiovascular implications. World J Urol. 2001; 19: 40–45
80. Montorsi F, Briganti A, Salonia A, Rigatti P, Margonato A, Macchi A, Galli S, Ravagnani PM, Montorsi P. Erectile dysfunction prevalence, time of onset and association with risk factors in 300 consecutive patients with acute chest pain and angiographically documented coronary artery disease. Eur Urol. 2003;44:360–364; discussion 364-365. [PubMed]
The vacuum device is approved by USA Food and Drug Administration (FDA) for treatment of ED since 1982. Vacuum therapy (VT) works by creating a negative pressure environment around the penis through the use of a cylindrical housing attached to a pump mechanism, which can be manually-operated or battery-operated. Vacuum draws mixed arterial and venous blood into the corporal bodies and distends the corporal sinusoids to create an erected penis. If a pre-loaded constriction band is applied over the base of the penis to prevent outflow of blood and maintain tumescence for intercourse, it is considered a vacuum constriction device (VCD). It is recommended that the constriction band be removed within 30 mins to return the penis to its flaccid state, as prolonged application of the constriction band can compromise both arterial and venous blood flow (7). Some minor side effects associated with VCD are penile discomfort, coldness, numbness, bruising and pain on ejaculation. Major side effects such as penile skin necrosis, gangrene, urethral injury and Peyronie’s disease are very rare (8).
Crossref | PubMed | Scopus (539) | Google ScholarSee all References Sleep studies in 175 patients with hypertension and erectile problems showed significantly lower penile rigidity measured by strain gauge plethysmography compared with 110 normotensive male controls with similar subjective erectile problems.33x33Hirshkowitz, M, Karacan, I, Gurakar, A, and Williams, RL. Hypertension, erectile dysfunction, and occult sleep apnea. Sleep. 1989; 12: 223–232

Erectile dysfunction (ED) is common, affecting almost 40% of men over 40 years of age (with varying degrees of severity) and increases in frequency with age.1 Erectile dysfunction and cardiovascular disease (CVD) share common risk factors including age, hypercholesterolaemia, hypertension, insulin resistance and diabetes, smoking, obesity, metabolic syndrome, sedentary lifestyle, and depression.2 Cardiovascular disease and ED also share a common pathophysiological basis of aetiology and progression.3 Numerous studies have established that ED (i) is frequent in men with established CVD, (ii) co-exists with occult coronary artery disease (CAD) and (iii) is an independent risk factor for future cardiovascular (CV) events both in men with established CVD and in men with no known CVD.2,4,5 In the latter group, ED precedes CAD, stroke, and peripheral arterial disease by a significant period that usually ranges from 2 to 5 years (average 3 years).2 Although the ED patient can be managed by various medical specialties, and preferably a collaborative approach is most effective, this review is oriented to the cardiologist. While this review deals exclusively with sexual health of men, female sexual health and its potential relation with CVD is also an interesting, yet underexplored, field. As in men, moderating common risk factors seems to improve female sexual health and may serve as an opportunity to decrease CVD risk, with the identification of sexual dysfunction being the starting point.6
But there are also medical devices like the Elator, which is approved by the Food and Drug Administration (FDA) and is custom-made with medical-grade silicone based on a patient’s girth and shaft. The technology, which has no known risk factors, has two thin bars that glide along the bottom of the penis, and hold the organ partially or fully erect with a soft, flexible loop, a sliding latch and a base lock and base ring.
After getting a diagnosis of ED, most patients can begin treatment right away, but treatment may be delayed for some patients until the health of the heart is more fully assessed or improved. The most common treatment for ED is a pill (phosphodiesterase-5 inhibitor; PDE5-I): Viagra (sildenafil), Cialis (tadalafil), or Levitra (vardenafil). Each of these pills improves erections when taken before sexual activity; alternatively, a low dose of Cialis can be taken once a day. These medicines work by allowing the blood vessels that supply blood to the penis to dilate better during sexual stimulation. The PDE5-Is decrease blood pressure a little bit, but they are safe with most other medications and with other blood pressure pills. The PDE5-Is are not safe with nitrate medications like nitroglycerin, Nitrostat, Nitro Paste, Imdur, isosorbide mononitrate, and Isordil. Mixing a PDE5-I with a nitrate medication could result in severely low blood pressure and even death. Inform all medical professionals (including the ambulance or emergency department) about your most recent ED pill ingestion so that nitrates can be avoided. If you have high blood pressure or benign prostatic hypertrophy (enlarged prostate) and take medicines called α-blockers, your doctor may need to start you on the lowest dose of the PDE5-I.
Sildenafil should be taken 1–2 h before intercourse. It is important to tell patients that the drug’s effectiveness requires sexual stimulation. One patient in our clinic recently complained that he had no effect from taking sildenafil. It was later discovered that he took the pill and then sat on his couch and read a book about how to grow tomatoes!

Erectile dysfunction (ED) is commonly called impotence. It’s a condition in which a man can’t achieve or maintain an erection during sexual performance. Symptoms may also include reduced sexual desire or libido. Your doctor is likely to diagnose you with ED if the condition lasts for more than a few weeks or months. ED affects as many as 30 million men in the United States.
Experts feel that treating erectile dysfunction on your own, without consulting a doctor, is unsafe. "If you have ED, the first thing you need is a diagnosis," says impotence expert Steven Lamm, MD, a New York City internist and the author of The Hardness Factor (Harper Collins) and other books on male sexual health. He says men with severe erectile dysfunction probably need one of the prescription ED drugs, which include Levitra (vardenafil) and Cialis (tadalafil) as well as Viagra. But, he says, mild ED -- including the feeling that "you're not as hard as you could be" -- often responds to natural remedies.
Crossref | PubMed | Scopus (25) | Google ScholarSee all References In comparison, a randomized placebo-controlled trial of 65 patients given either placebo or 95 mg/d of sustained-release metoprolol for 4 months after percutaneous coronary angioplasty found no significant difference in sexual function between the 2 groups.44x44Franzen, D, Metha, A, Seifert, N, Braun, M, and Hopp, HW. Effects of beta-blockers on sexual performance in men with coronary heart disease: a prospective, randomized and double blinded study. Int J Impot Res. 2001; 13: 348–351

** Indeterminate risk patients include diabetics, those with mild or moderate stable angina pectoris, past myocardial infarction (2-8 wks) without intervention awaiting exercise electrocardiography, congestive heart failure (NYHA class III), and noncardiac sequelae of atherosclerotic disease (eg, peripheral artery disease and a history of stroke or transient ischemic attack); this patient with ED may require assessment for additional vascular disease using carotid intima-media thickness or ankle-brachial index and subsequent reclassification to low or high risk.


Abnormalities in the vascular, neural, endocrine, muscular, or psychiatric systems can result in ED.2,3 EDDM is due to multisystemic disease. Atrophy or apoptosis of cavernosal smooth muscle can occur due to loss of Bcl-2 expression in cavernosal smooth muscle and lead to ED. Abnormal amounts of advanced glycation end products is a common occurrence. These chemicals may have an effect on potassium channels that facilitate intracellular calcium release and subsequent cavernosal smooth muscle relaxation. Connective tissue synthesis is increased due to transforming growth factor-beta. The decrease in smooth muscle and the increase in collagen decreases the compliance of the erectile tissue. Neuropathic damage to both the somatic and autonomic nerves has been clearly defined in DM. Partial occlusion of the pelvic or intracavernosal arteries, hypogonadotropic hypogonadism, and depression associated with a chronic illness (DM) can all play a primary or secondary role in the development of EDDM. On a molecular level, studies have demonstrated decreased levels of endothelial and neuronal nitric acid synthase (NS) and decreased cavernosal artery and sinusoidal response to nitric oxide. Abnormalities in nitric oxide rapidly render the functional syncytium of the corpora cavernosa unable to synchronously relax. As the patient with diabetes ages, the concentration of constrictors, including endothelin, prostanoids, and possibly angiotensin, increases as the production of the relaxants, including nitric oxide, vasointestinal peptide, and prostacyclin, decreases.

• Blood Vessels: Diabetes damages blood vessels, especially the smallest blood vessels such as those in the penis. Diabetes can also cause heart disease and other circulatory problems. Proper blood flow is absolutely crucial to achieving erection. “Erection is a hydraulic phenomenon that occurs involuntarily,” says Arturo Rolla, MD, of Harvard University School of Medicine. “Nobody can will an erection!” Anything that limits or impairs blood flow can interfere with the ability to achieve an erection, no matter how strong one’s sexual desire.
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