A number of nonprescription products claim to be herbal forms of Viagra. Some of these products contain unknown amounts of ingredients similar to those in prescription medications, which can cause dangerous side effects. Some actually contain the real drug, which should be given by prescription only. Although the Food and Drug Administration has banned many of these products, some potentially dangerous erectile dysfunction remedies remain on the market.

In an open-label study, 8 patients monitored with a Swan-Ganz catheter were given a total of 40 mg of sildenafil in 4 intravenous transfusions (the equivalent of 1 to 3 times the plasma concentration after an oral dose of 100 mg).62x62Jackson, G, Benjamin, N, Jackson, N, and Allen, MJ. Effects of sildenafil citrate on human hemodynamics. Am J Cardiol. 1999; 83: 13C–20C

Apostolo A,  Vignati C,  Brusoni D,  Cattadori G,  Contini M,  Veglia F,  Magrì D,  Palermo P,  Tedesco C,  Doria E,  Fiorentini C,  Montorsi P,  Agostoni P. Erectile dysfunction in heart failure: correlation with severity, exercise performance, comorbidities, and heart failure treatment, J Sex Med , 2009, vol. 6 (pg. 2795-2805)https://doi.org/10.1111/j.1743-6109.2009.01416.x
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.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (58) | Google ScholarSee all References Theoretically, the risk of a cardiac event during sexual activity should be increased. Sexual activity is associated with an elevated heart rate, blood pressure level, and myocardial oxygen demand, and this increase in hemodynamic stress may result in myocardial ischemia.79x79Kimmel, SE. Sex and myocardial infarction: an epidemiologic perspective. Am J Cardiol. 2000; 86: 10F–13F
Low testosterone levels have been observed inconsistently in STZ-induced diabetic and BB rats.18 Androgen deficiency in rats is associated with downregulation of the neuronal isoforms of nitric oxide synthase, suggesting a trophic effect of testosterone on peripheral erectile tissues. In humans, androgens play a larger role in sexual interest and motivation (libido) than in erectile capacity itself; penile erection is more resistant to androgen withdrawal than is sexual desire.19,20

According to the Cleveland Clinic, “because erectile dysfunction is caused by a complex set of psychosocial, neurologic, and vascular factors, a specific cause in a patient may remain ambiguous.” The root causes are often related to a blockage or dysfunction of blood vessels. For example, ED can be due to conditions like atherosclerosis or diabetes, hormonal imbalances or problems related to mental health. It’s been found that common causes typically include one or more of the following factors: (2)
Furthermore, if feelings of sadness, bloating, or weight gain are prominent, it may be beneficial to measure a form of estrogen called estradiol. This form of estrogen can be elevated in men, particularly in those who are overweight, and may trigger these abnormal responses, increasing the risk of heart disease. Estradiol levels above 30 pg/mL are generally considered abnormal. Weight loss can help correct elevated estradiol, as can prescription “aromatase inhibitors,” such as Arimidex®. In addition, a nutritional supplement called chrysin has been shown in the laboratory to inhibit the aromatase enzyme that is responsible for converting testosterone to estradiol.24 You should consult your doctor to determine if this supplement may be helpful for you.
Relaxation of erectile tissue requires nitric oxide from nonadrenergic-noncholinergic neurons and the endothelium.21 Penile tissue from diabetic men with ED demonstrates impaired neurogenic and endothelium-mediated relaxation of smooth muscle,22 increased accumulation of advanced glycation end products (AGEs),23 and upregulation arginase, a competitor with nitric oxide synthase for its substrate L-arginine.24 Normal responses to direct smooth muscle relaxants in most of these studies implies that the impairments are due to decreased synthesis, release, or activity of nitric oxide. The fundamental mechanisms mediating these changes are thought to be the same as for other diabetic complications: increased polyol pathway flux, intracellular accumulation of AGEs, activation of protein kinase C, and increased flux through the hexosamine pathway.25

Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Phase 2 and 3 trials reported minimal associated cardiac adverse effects, which occurred in 3% of patients taking sildenafil and in 3.5% of patients receiving placebos.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
Erectile dysfunction (ED) can be treated by urologists or other specialists or even by your general practitioner. Your doctor may recommend medication that works by relaxing penis muscles and increasing blood flow into the penis. Other treatments include therapy, implants, surgery and lifestyle changes, like exercising regularly, losing weight and eating right.
Yohimbine is an indole alkaloid derived from the bark of the African yohimbe tree (33). Yohimbine has been noted to treat fatigue, depression, diabetes, and sexual dysfunction. A meta-analysis of seven placebo-controlled trials (34) deemed yohimbine superior to placebo for the treatment of ED with rare adverse events. The proposed mechanism of action (35) is via the inhibition of central alpha-2-adrenergic receptors, decreasing central inhibition of arousal, and increasing penile nerve stimulation resulting in increased NO. Common side effects include headache, sweating, agitation, hypertension and insomnia. Contraindications include patients on tricyclic antidepressants, anti-hypertensives and central nervous system stimulants.
Diabetes care providers, while becoming more aware of the high prevalence of ED in men with diabetes, may not appreciate the importance of maintaining erectile function to their patients. A recent study by Rance et al.40 underscores the fact that diabetic men, regardless of whether they actually have ED, believe that ED has a major impact on quality of life and that it is as important to treat as many other conditions associated with diabetes. In an effort to determine the relative importance of treatment for ED compared to other diabetic complications, they gave 192 consecutive diabetic men and 51 control patients seen at two hospitals a standardized questionnaire that assessed the relative importance of a number of diabetic complications and the patients' willingness to pay per month to avoid a particular complication.
The diagnosis of ED in a patient may affect its management in two ways.30 The first relates to the fact that the ED patient, irrespective of whether he has or has not established CVD, is ‘reclassified’ into a higher risk category for future CV events. Management in this case is altered in the sense that more aggressive treatment of risk factors, as well as a close follow-up, is warranted. Implementation of biomarkers in this setting is desirable.
Recent revised labeling for sildenafil states that there is a lack of controlled data for its use in patients with resting hypotension (<90/50 mm Hg) or hypertension (>170/110 mm Hg); a history of myocardial infarction, cerebrovascular accident, or life-threatening arrhythmia within the past 6 months; coronary artery disease or cardiac failure causing unstable angina; or retinitis pigmentosa and possible genetic disorders of retinal PDEs.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
If you take a diuretic, you should stay on it until high blood pressure is under control. If erection problems persist, or blood pressure goes back up, then your doctor might switch to a drug that's less likely to cause erectile dysfunction. Or, a combination of medications might work better to control high blood pressure and lower the risk of erectile dysfunction.
For centuries, men have tried all sorts of natural remedies for erectile dysfunction (ED) -- the repeated inability to get or maintain an erection firm enough for sexual intercourse. But do they really work? It is simply not scientifically known at this point. Furthermore, you take these remedies at your own risk, because their safety profiles have not been established. What follows are commentaries by experts and reviews in the field of alternative treatments that are available over the counter for erectile dysfunction and impotence.
Low testosterone levels have been observed inconsistently in STZ-induced diabetic and BB rats.18 Androgen deficiency in rats is associated with downregulation of the neuronal isoforms of nitric oxide synthase, suggesting a trophic effect of testosterone on peripheral erectile tissues. In humans, androgens play a larger role in sexual interest and motivation (libido) than in erectile capacity itself; penile erection is more resistant to androgen withdrawal than is sexual desire.19,20
The diagnosis of ED in a patient may affect its management in two ways.30 The first relates to the fact that the ED patient, irrespective of whether he has or has not established CVD, is ‘reclassified’ into a higher risk category for future CV events. Management in this case is altered in the sense that more aggressive treatment of risk factors, as well as a close follow-up, is warranted. Implementation of biomarkers in this setting is desirable.

Perk J,  De Backer G,  Gohlke H,  Graham I,  Reiner Z,  Verschuren WM,  Albus C,  Benlian P,  Boysen G,  Cifkova R,  Deaton C,  Ebrahim S,  Fisher M,  Germano G,  Hobbs R,  Hoes A,  Karadeniz S,  Mezzani A,  Prescott E,  Ryden L,  Scherer M,  Syvänne M,  Scholte Op Reimer WJ,  Vrints C,  Wood D,  Zamorano JL,  Zannad F. European Guidelines on cardiovascular disease prevention in clinical practice (version 2012). The Fifth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (constituted by representatives of nine societies and by invited experts). Developed with the special contribution of the European Association for Cardiovascular Prevention & Rehabilitation (EACPR), Eur Heart J , 2012, vol. 33 (pg. 1635-1701)https://doi.org/10.1093/eurheartj/ehs092


The vascular endothelium has an important role in angiogenesis and vascular repair by producing regulatory substances, including NO, prostaglandin, endothelins, prostacyclin and angiotensin II. These regulatory factors regulate the blood flow to the penis by controlling smooth muscle contractility and subsequent vasoconstriction and vasodilatation. Generally, in erectile tissue, increased blood flow through the cavernosal artery increases shear stress and produces NO, which further relaxes the vascular smooth muscles and increases blood flow in the corpora cavernosa.54 These events cause penile erection. However, in ED, endothelial NO synthesis is reduced and there is increased endothelial cell death (Figure 2).55
Penile prosthesis implant remains the most effective and permanent treatment for ED. Penile prosthesis implants can be broadly divided into malleable and inflatable prostheses (20). Malleable penile prosthesis, also known as semi-rigid prosthesis, does not allow for (physiological) flaccid state of the penis. The patient can bend the prosthesis upwards for sexual intercourse and downwards for concealment. Although the angle of prosthesis concealment has improved with recent devices, however due to the constant rigid state of the penis, they are still less comfortable compared to their inflatable counterparts, are more likely to cause social embarrassment and associated with higher risk of implant erosions (21). However, malleable prosthesis still has its place for the treatment of ED as these implants are easier to handle, easier to place and would benefit patients with impaired manual dexterity.
• 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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