Treatment of erectile dysfunction in men with diabetes

Erectile dysfunction in patients with diabetes mellitus — advances in treatment with phosphodiesterase type 5 inhibitors

Erectile dysfunction (ED) is a common complication of diabetes mellitus. In four independent, 12-week, randomised, placebo-controlled clinical trials that evaluated the pro-erectile properties of the selective phosphodiesterase type 5 (PDE-5) inhibitors, sildenafil (Viagra) (25—100 mg), tadalafil (10 and 20 mg) and vardenafil (10 and 20 mg) in men with ED secondary to diabetes mellitus, all the active drugs were significantly superior to placebo. In this difficult-to-treat population, the greatest difference from placebo for the overall responder rate of diabetic men reporting improved erections occurred with vardenafil 20 mg (72% vs. 13% for placebo).

All the PDE-5 inhibitors were generally well tolerated. There were fewer reports of visual disturbance with vardenafil or tadalafil than with sildenafil, which may be due to their greater selectivity for PDE-5 inhibition and less cross-reactivity with retinal PDE-6 inhibition.

The studies suggest there may be significant differences between the three drugs. However, only head-to-head studies will determine true differences in both efficacy and side effect profile.

ORIGINAL RESEARCH—ENDOCRINOLOGY: The Effect of Diabetes Mellitus Treatment and Good Glycemic Control on the Erectile Function in Men with Diabetes Mellitus‐Induced Erectile Dysfunction: A Pilot Study

INTRODUCTION

Erectile dysfunction (ED) is a common complication of diabetes mellitus (DM). However, efficacy and/or long-term satisfaction with most of those ED treatment options have been suboptimal.

AIM

In this study we try to evaluate the effect of aggressive treatment and DM regulation on the erectile function in men with DM-induced ED (DMED).

METHODS

Eight type 1 and 17 type 2 diabetic subjects were included into the study. All patients had a measurement of fasting plasma glucose (FPG) and glycosylated hemoglobin (HbA1(c)) levels, and completed three sessions of consecutive nights using the RigiScan Plus monitoring device before and after blood sugar control. Also International Index of Erectile Function (IIEF) questionnaire scores were obtained before and after blood sugar control.

RESULTS

Significant improvement was noted in FPG and HbA1(c) levels throughout the treatment period (P < 0.001). However, no statistically significant difference was observed in both IIEF scores and nocturnal penile tumescence and rigidity (nptr) parameters after the dm regulation (p > 0.05).

CONCLUSION

We suggest that there are probably other factors than aggressive treatment and DM regulation for treating DMED, and probably we must consider preventive strategies with pharmacological agents to prevent progressive decrease in erectile function in diabetic patients.

Evaluation of a progressive treatment program for erectile dysfunction in patients with diabetes mellitus

The aim was to evaluate the effectiveness of a progressive program, starting with simple methods and, when not effective, moving to more complex methods, to treat erectile dysfunction (ED) in patients with diabetes mellitus. A total of 284 diabetic patients with ED entered into a 6-phase program starting with sildenafil citrate (Viagra). Those with contraindications, side effects, or negative response (erection insufficient for vaginal penetration) were switched to the vacuum erection device (VED), and then progressively (for failures) to intracavernous injection (ICI), sildenafil citrate+ICI, ICI+VED, and penile prosthesis. Patients were followed for 2 y. Of the 284 patients 276 patients were eligible for sildenafil citrate and 147 (53.3%) responded positively, but 25 (9.1%) patients stopped it soon due to adverse effects. Of 162 patients (129 nonresponders, eight noneligible for the sildenafil and 25 patients who dropped out due to adverse effects), treated with VED, 114 (70.4%) responded well, however, only 19 (11.7%) patients agreed to continue its use. Of the remaining 143 patients (nonresponders, noneligible for the previously mentioned treatments and patients who dropped out due to adverse effects), 103/143 (72%) responded to ICI, 27/40 (67.5%) to sildenafil+ICI, and 9/13 (69.2%) to ICI+VED. Four patients received a penile implant. At the 2 y follow-up, 81 of 284 patients who entered the study (28.5%) were still responding to sildenafil, seven (2.5%) to VED, 113 (39.8%) to ICI, 24 (8.5%) to sildenafil+ICI, two (0.7%) to ICI+VED; 15 (5.3%) had a penile implant. In all 17 (6%) patients reported spontaneous erections, 11 (3.9%) stopped the treatment due to family reasons and 14 (4.9%) failed the treatment. In conclusion, the progressive treatment program for ED seems to be very effective for diabetic patients, yielded a complete response for short-term and 91.2% rate of success at the end of 2 y follow-up.

Sildenafil in the treatment of erectile dysfunction in men with diabetes: demand, efficacy and patient satisfaction

The objective of this study is to describe the eligibility, consumption, efficacy and patient satisfaction when treating men with diabetes with Sildenafil. The study is a prospective, self-reported, flexible-dose study. In total, 45 patients with diabetes (type 1 or 2), complaining of erectile dysfunction, were treated with Sildenafil over a 12-week period. Efficacy was assessed using a patientlog, a general satisfaction questionnaire and the International Index of Erectile Function (IIEF). Of 326 men, 192 reported erectile dysfunction, 79 did not fulfil the criteria for Sildenafil treatment and 49 declined to participate. In the group of 33 (age 45-75 y, mean+/-s.d.: 58.1+/-7.2) completing the study, erectile function was significantly improved (P < 0.0001). A total of 12 patients (36.4%) experienced no treatment effect at all. Eligibility and desire for treatment was low. Sildenafil is far from being a 'cure all' in the treatment of ED in diabetes.

New Treatment Options for Erectile Dysfunction in Patients with Diabetes Mellitus

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.

Pharm-ing cyberspace: the Internet as a tool for evidence based pharmacotherapy

Although the Internet lacks many of the features of a desirable drug information system, it has increasing potential to inform evidence-based patient management. This article considers three contributions that the Internet can make to evidence-based pharmacotherapy; as a delivery mechanism for textual documents, as a complementary source of intelligence and as a source of value-added information. Focusing on exemplar sites, rather than on drug and information sources in general, the author reviews the usefulness and availability of current resources. While limitations of the technology presently constrain its use for direct patient care and the quality of any information must be critically appraised, the Internet has already proved a valuable source for drug evaluation, education, research and audit.