Since their introduction in the therapeutic field, more than a decade ago, PDE-5 inhibitors have revolutionized the treatment of sexual dysfunction. By blocking the activity of PDE-5 isoenzyme, localized throughout the smooth muscle cells of the vasculature (genital vessels included), PDE-5 inhibitors increase the levels of cyclic guanosine monophosphate thus exerting vasodilating properties and facilitating penile erection[40-42]. Due to these properties, sildenafil was the first drug of its class to receive wide acceptance. Its short half-life, food interactions and the associated visual disturbances however, paved the way for the development of newer PDE-5 inhibitors. As such vardenafil with its more rapid onset of action, and tadalafil with its longer half-life and the lack of food interactions or side effects, have offered significant alternatives to sildenafil[43-50].
The natural history of ED in people with diabetes is normally gradual and does not occur overnight. Both vascular and neurological mechanisms are most commonly involved in people with diabetes. Atherosclerosis in the penile and pudendal arteries limits the blood flow into the corpus cavernosum. Because of the loss of compliance in the cavernous trabeculae, the venous flow is also lost. This loss of flow results in the inability of the corpora cavernosae to expand and compress the outflow vessels.
Chronic heart failure often develops after other cardiac problems have damaged or weakened the heart, leaving it too weak or too stiff to fill and pump efficiently. Many underlying heart conditions can lead to heart failure. It can develop quickly after damage caused by a heart attack, or it can develop gradually after years of high blood pressure or coronary artery disease.

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.


The safety of PDE5 inhibitors in patients with IHD has been shown in multiple trials. Arruda-Olson et al. investigated the safety of sildenafil during exercise stress tests in patients with IHD to ascertain whether the drug induces or exacerbates myocardial ischaemia. This was a prospective, randomised crossover study that demonstrated safety of sildenafil when given 1 hour before an exercise stress test.69 Another study that investigated 120 trials of sildenafil revealed that the rates of MI and cardiovascular death with sildenafil are as low as with placebo.70
Prescription drugs called “oral phosphodiesterase-5 (PDE5) inhibitors” are considered the “first-line non-invasive treatment” options for patients with ED. These include the drugs that go by brand names: Sildenafil, Vardenafil or Tadalafil. They work by helping the smooth muscle cells lining the blood vessels that supply the penis with blood to work properly. This allows a man to maintain an erection more easily.
Abstract | Full Text PDF | PubMed | Scopus (19) | Google ScholarSee all References However, there has been disagreement regarding the effects of diuretics on erectile function; many studies found that only rarely have these medications been implicated convincingly as the cause of a patient's ED.36x36Wein, AJ and Van Arsdalen, KN. Drug-induced male sexual dysfunction. Urol Clin North Am. 1988; 15: 23–31
Crossref | PubMed | Google ScholarSee all References Regular exercise can significantly decrease the patient's risk of having a myocardial infarction during sexual intercourse by increasing the patient's functional reserve, decreasing the heart rate, and increasing the stroke volume.8x8Muller, JE, Mittleman, A, Maclure, M, Sherwood, JB, Tofler, GH, and Determinants of Myocardial Infarction Onset Study Investigators. Triggering myocardial infarction by sexual activity: low absolute risk and prevention by regular physical exertion. JAMA. 1996; 275: 1405–1409
Control your blood sugar through your diet. Eating a diabetes-friendly diet will help you better control your blood sugar levels and lessen the amount of damage to your blood vessels and nerves. A proper diet geared at keeping your blood sugar levels in check can also improve your energy levels and mood, both of which can help reduce the risk of erectile dysfunction. You may consider working with a dietitian who is also a certified diabetes educator to help adjust your eating style.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (124) | Google ScholarSee all References This was a doubleblind, single-dose crossover study involving 41 men with stable coronary artery disease characterized by reproducible stable exertional angina. After taking either 10 mg of vardenafil or placebo, these men underwent treadmill exercise tolerance testing to 5 to 10 METs. Compared with placebo, vardenafil use did not result in a change in exercise treadmill time or time to first awareness of angina but significantly increased the time to ischemic threshold. At peak exercise levels, vardenafil did not cause a change in either heart rate or blood pressure level. This study concluded that 10 mg of vardenafil did not impair the ability of men with stable coronary artery disease to exercise at levels consistent with the exertion associated with sexual intercourse.
Smoking is an independent risk factor for ED. Tobacco smoking causes direct toxicity to endothelial cells, including decreased eNOS activity, increased adhesion expression and impaired regulation of thrombotic factors.6 A meta-analysis of 19 studies by Tengs and Osgood suggested that 40 % of the impotent men studied were current smokers compared with 28 % who had never smoked.49
Some blood pressure medicines can also cause erectile dysfunction. Thiazide diuretics and beta-blockers are most likely to cause problems, but this is not a common effect of these medicines and will not happen to everyone. If you are taking either of these medicines and are worried about erectile dysfunction, your GP may be able to change your medicines.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (207) | Google ScholarSee all References Adverse-effect profiles of headaches, flushing, rhinitis, and dyspepsia, without visual changes, mimic those of vardenafil.74x74Gresser, U and Gleiter, CH. Erectile dysfunction: comparison of efficacy and side effects of the PDE-5 inhibitors sildenafil, vardenafil and tadalafil—review of the literature. Eur J Med Res. 2002; 7: 435–446
Crossref | PubMed | Scopus (528) | Google ScholarSee all References Sildenafil also has good efficacy in patients with ischemic heart disease, as shown by a retrospective subanalysis of data from 11 double-blind, placebo-controlled studies involving 3672 patients with ED and ischemic heart disease who were not taking nitrates.59x59Kloner, RA. Cardiovascular risk and sildenafil. Am J Cardiol. 2000; 86: 57F–61F

Some research even suggests the effect of blood pressure drugs may be more psychological than physical. When ED occurs after a man begins to take a new medication, it's possible that anxiety about his health, rather than the medication, may trigger the problem. And being aware of possible side effects may make a man more likely to recognize them as abnormal.
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
Dr. Eid also urges these patients to treat their diabetes in order to avoid developing ED for life. “They need to manage their diabetes and make sure they control it so the ED will not progress and will stabilize, as a result,” he said. “If the diabetes is controlled after the patient is first diagnosed, then the erections will come back. But if the patient has diabetes for many years, and suddenly decides it’s time to control it, they cannot prevent the damage that’s already been done.”
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References In conclusion, sildenafil, when used alone, seems to produce minimal decreases in blood pressure level, which are well tolerated in healthy patients and in those with stable ischemic coronary disease.3x3Zusman, RM, Morales, A, Glasser, DB, and Osterloh, IH. Overall cardiovascular profile of sildenafil citrate. Am J Cardiol. 1999; 83: 35C–44C
Normal penile erection is controlled by two mechanisms: reflex erection and psychogenic erection. Reflex erection occurs by directly touching the shaft of the penis, while psychogenic erection occurs by erotic or emotional stimuli. ED is a condition where erection does not take place by either mechanism. ED can occur because of hormonal imbalance, neural disorders or lack of adequate blood supply to the penis.54 Lack of blood supply can be a result of impaired endothelial function associated with CAD.54
There are blood pressure medications that do not cause erectile dysfunction (ED). Some older blood pressure medications, especially beta blockers and thiazide diuretics, are the most likely to cause ED as a side effect. Better options include calcium channel blockers, which lower high blood pressure through a different mechanism. Don't just go off your medications, though; high blood pressure itself is a common cause of ED, so lowering your blood pressure is an important part of your ED treatment plan. And if you stop taking your blood pressure medications 'cold turkey', your blood pressure could actually sky rocket, putting you at risk for a heart attack or a stroke. Work with your doctor on ways to lower your blood pressure without lowering your sex drive.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (56) | Google ScholarSee all References Cardiologists use METs of oxygen consumption to compare the energy expenditure of different forms of activity.51x51DeBusk, R, Drory, Y, Goldstein, I et al. Management of sexual dysfunction in patients with cardiovascular disease: recommendations of the Princeton Consensus Panel. Am J Cardiol. 2000; 86: 62F–68F
Crossref | PubMed | Scopus (56) | Google ScholarSee all References When matched for age, hypertension, diabetes, and tobacco use, no significant difference was noted in the presence of ED (42% in the myocardial infarction group vs 48% in the control group). However, the presence of severe congestive heart failure has been associated with increased ED. A study of 80 patients with New York Heart Association class III/IV congestive heart failure found that 40% of these patients had complete ED, and another 40% had either mild or moderate ED.15x15Taylor, HA Jr. Sexual activity and the cardiovascular patient: guidelines. Am J Cardiol. 1999; 84: 6N–10N
Experimental in vivo studies have implicated central and peripheral neuropathy, impaired neurotransmission, and endothelial dysfunction in the pathogenesis of diabetic ED.26,27 Copulatory behavior and penile reflexes are uniformly impaired 4–12 months after the onset of diabetes in the BB rat.26,27 McVary et al.26 found that peripheral neuropathy accounts for only part of the dysfunctional findings, and that spinal sexual reflexes were also severely impaired.
Montorsi P,  Ravagnani PM,  Galli S,  Rotatori F,  Veglia F,  Briganti A,  Salonia A,  Dehò F,  Rigatti P,  Montorsi F,  Fiorentini C. Association between erectile dysfunction and coronary artery disease. Role of coronary clinical presentation and extent of coronary vessels involvement: the COBRA trial, Eur Heart J , 2006, vol. 27 (pg. 2632-2639)https://doi.org/10.1093/eurheartj/ehl142

Age is a critical risk factor for the development of ED and endothelial dysfunction.4,5 ED is the most common condition occurring in middle-aged and older men.5 Kinsey et al. reported that 25 % of 65-year-old men and 75 % of ≥80-year-old men have ED.39 Moreover, ageing also decreases endothelial function, which is responsible for IHD.5 The incidence and severity of ED increases with age (a man aged 70 years is three-times more likely to have ED than a man aged 40 years).40


Crossref | PubMed | Scopus (42) | Google ScholarSee all References Apomorphine does not appear to have any notable cardiovascular adverse effects and has been used successfully in Europe. However, apomorphine use has been associated with other unpleasant adverse effects such as nausea and emesis, and the drug has not been approved by the US Food and Drug Administration (FDA) for use in the United States.
Although medication can help extend the lives of men with chronic heart failure, several factors associated with this disease can interfere with a person's ability to engage in and enjoy sexual activities. Fatigue, depression, medication side effects and the fear of damaging the heart can cause people with chronic heart failure to lose interest in sex or wonder whether this activity is safe for them.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Sildenafil is absorbed rapidly, and peak plasma levels of 127 to 560 ng/mL are seen in a fasting state approximately 1 hour (range, 0.5-2 hours) after ingestion.3x3Zusman, RM, Morales, A, Glasser, DB, and Osterloh, IH. Overall cardiovascular profile of sildenafil citrate. Am J Cardiol. 1999; 83: 35C–44C
The pilot study by Vardi et al. (18) showed that LIESWT was effective in treating men with ED, suggesting a physiologic impact of LIESWT on cavernosal hemodynamics. The LIESWT is an effective penile rehabilitation tool that improves erectile function and potentially reverses underlying ED. Recent meta-analysis (19) of 14 studies showed that LiESWT could significantly improve the International Index of Erectile Function (IIEF) [mean difference: 2.00; 95% confidence interval (CI), 0.99–3.00; P<0.0001] and Erection Hardness Score (EHS) (risk difference: 0.16; 95% CI, 0.04–0.29; P=0.01). In addition, the therapeutic efficacy was noted to last for at least 3 months. LiESWT has been cited to a potential cure for ED, unlike other well established non-surgical methods of treatment (i.e., PDE5i, ICI and VED) being on demand treatments.

Chlamydia and erectile dysfunction: What's the link? Some people who have chlamydia also experience erectile dysfunction (ED), which involves problems getting or maintaining an erection. Chlamydia can infect the prostate gland, leading to prostatitis, pain, and ED. In this article, learn more about the link between this common infection and ED, and treatments for both. Read now
There are currently two models of the inflatable penile prosthesis (IPP), namely, the two-piece IPP vs. the three-piece IPP. The three-piece IPP consists of a pair of corporal cylinders, a scrotal pump and an abdominal reservoir filled with saline. Owing to the presence of the reservoir, the corporal cylinders can be completely deflated to give the patient the physiological flaccid state when not in use, and likewise a maximally turgid state when inflated (21). The two-piece IPP lacks an abdominal reservoir and is often offered in patients with whom placement of reservoir is challenging or not possible such as following radical cysto-prostatectomy with orthotopic ileal neobladder creation, or patients who had previous open book fracture of the pelvis with metal implants. The concept of ectopic reservoir placement has allowed many of these men the option for three-piece IPP placement (22). Technological advances have improved mechanical reliability, reduced prosthesis infection risk and offered excellent patient and partner satisfaction rate (23).
Abstract | Full Text PDF | PubMed | Scopus (3562) | Google ScholarSee all References The 9-year follow-up MMAS study also found that self-reported increased cholesterol and unsaturated fat intake correlated positively with the development of ED.5x5Feldman, HA, Johannes, CB, Derby, CA et al. Erectile dysfunction and coronary risk factors: prospective results from the Massachusetts Male Aging Study. Prev Med. 2000; 30: 328–338
Does drinking water improve erectile dysfunction? Erectile dysfunction or ED is a common concern for men. Everyday factors, such as hydration levels, may affect a person's ability to get or maintain an erection. Drinking water may, therefore, help some men with ED. In this article, learn about the link between hydration and ED, and other factors that can cause ED. Read now
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