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.


Andersson said the results came as a surprise because erectile dysfunction is associated with an increased risk of heart disease in otherwise healthy men. However, previous studies have associated the use of PDE5 inhibitors with a decreased blood pressure in the left ventricle, which reduces the amount of work required to pump blood and therefore could help explain why the drugs might benefit people with heart failure. PDE5 inhibitors were initially developed to treat angina, a type of chest pain that results from constricted arteries.
Due to their vasorelaxing effect, administration of PDE-5 inhibitors in hypertensive individuals was initially confronted with great suspicion. A wealth of clinical data however has proven that PDE-5 inhibitors are associated with few side effects and provoke a small and insignificant reduction in blood pressure with minimal heart rate alterations in both normotensive and hypertensive patients as well. As a matter of fact, they can be safely and effectively administered to hypertensive individuals even when they are already taking multiple antihypertensive agents[51-56]. The sole exception to the rule is co-administration with organic nitrates, which is an absolute contraindication due to profound and possibly hazardous hypotension effect[57,58]. Moreover, precaution should be taken when PDE-5 inhibitors are combined with a-blockers where, due to possible orthostatic hypotension effect, lower starting doses should be implemented in the therapeutic regime[59-62].
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References During this period, 130 deaths were reported to the US FDA; 41 of these men died or had cardiac arrest within 4 to 5 hours after taking sildenafil, and 27 died or had cardiac arrest either during or immediately after sexual activity. The average age of these men was 64 years. Of the 77 men in this group who died of documented cardiovascular-related events, 41 died of definite or suspected myocardial infarction, 27 died after cardiac arrest, and 6 had symptoms of cardiac disease at the time of death. Sixteen of the men had taken nitroglycerin or organic nitrates in association with sildenafil; another 3 had nitroglycerin in their possession at the time of death. In 48 men, the cause of death was unknown, and another 3 died of cerebrovascular accidents. Overall, it was concluded that sildenafil was not associated with an excess of cardiovascular death.

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Alprostadil self-injection. With this method, you use a fine needle to inject alprostadil (Caverject Impulse, Edex) into the base or side of your penis. In some cases, medications generally used for other conditions are used for penile injections on their own or in combination. Examples include papaverine, alprostadil and phentolamine. Often these combination medications are known as bimix (if two medications are included) or trimix (if three are included).
DHEA is a hormone made by the human body. It’s a building block for testosterone. According to a study published in Urology, this supplement may be able to help men whose ED is related to having low testosterone. However, there’s no definitive evidence of this benefit. It’s clear that DHEA can cause various side effects, including liver damage and acne. Long-term use of DHEA can also cause hormonal imbalances.
The bottom line is that nearly all men with diabetes who wish to have an erection adequate for sexual intercourse can do so with the therapies currently available. And with commitment and communication, the experience of erectile dysfunction can be changed from a potential personal tragedy to an opportunity for greater emotional intimacy in a couple.

Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Sildenafil is taken orally 1 hour before anticipated sexual intercourse and enhances the normal response to sexual stimulation; however, it has no effect on erections in the absence of stimulation.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
Abstract | Full Text | Full Text PDF | PubMed | Scopus (66) | Google ScholarSee all References However, some researchers have questioned whether the strain of sexual activity can be compared accurately with standard types of physical activity and whether sexual activity is more closely related to episodes of anger or fear.85x85DeBusk, RF. Evaluating the cardiovascular tolerance for sex. Am J Cardiol. 2000; 86: 51F–56F
Ginkgo is an herb that’s been used medicinally for thousands of years to treat a variety of ailments. This supplement may improve penile blood flow. Additionally, some reports suggest that ginkgo can increase bleeding risk. This makes it particularly dangerous for people using blood thinners. Other studies, including one from 2011, found no evidence of increased bleeding while using ginkgo.
According to the Mayo Clinic, oral medications are usually the first-line treatment for ED. Those medications include Sildenafil (Viagra), vardenafil (Levitra, Staxyn), tadalafil (Cialis) and avanafil (Stendra). They operate by helping relax muscles in the penis by strengthening the effects of nitric oxide, a naturally occurring chemical in the body. The drugs increase blood flow to allow patients to get an erection.
For oral erectile dysfunction medicines to work as desired, they must be used properly in the first place. This means taking the medicine 30–45 minutes before engaging in sexual intimacy; taking the drug on an empty stomach or at least avoiding a heavy or high-fat meal before taking the drug (this is especially important when using sildenafil); and engaging in adequate genital stimulation before attempting intercourse. Drinking small amounts of alcohol (one to two drinks) should not compromise the effectiveness of erectile dysfunction medicines, but larger amounts of alcohol can diminish a man’s ability to have an erection.
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