NO is produced by the enzyme NO synthase (NOS).  NOS plays many roles, ranging from homeostasis to immune system regulation. To date, 3 subtypes have been identified: nNOS, iNOS, and eNOS, which are produced by the genes NOS1, NOS2, and NOS3, respectively. This nomenclature is derived from the sources of the original isolates: neuronal tissue (nNOS), immunoactivated macrophage cell lines (iNOS), and vascular endothelium (eNOS). The subtypes are not, however, limited to the tissues from which they were first isolated.
ED can be caused by either physical and/or psychological factors like stress, anxiety, or depression. Importantly, ED can be the first sign of heart or other health conditions, including cardiovascular disease and diabetes. We offer the optional order of a lab test to investigate whether you might have more serious underlying health problems. Our doctors can order investigative labs in all the states we operate in apart from AZ, NY, NJ and RI. You’ll need to go to a Quest Diagnostics center to have these tests done. When we get the test results back, we can help you understand what they mean.
In most healthy men, some of the drug will remain in the body for more than two days after a single dose of tadalafil. Metabolism (clearing of the drug from the body) of tadalafil can be slowed by liver disease, kidney disease, and concurrent use of certain medications (such as erythromycin, ketoconazole, and protease inhibitors). Slowed breakdown allows tadalafil to stay in the body longer and potentially increase the risk for side effects. Therefore, doctors have to lower the dose and frequency of tadalafil in the following examples:
Psychological factors — Psychological issues such as depression, anxiety, guilt or fear can sometimes cause sexual problems. At one time, these factors were thought to be the major cause of impotence. Doctors now know that physical factors cause impotence in most men with the problem. However, embarrassment or "performance anxiety" can make a physical problem worse.
One report from a recent community survey concluded that erectile failure was the leading complaint of males attending sex therapy clinics. Other studies have shown that erectile disorders are the primary concern of sex therapy patients in treatment. This is consistent with the view that erectile dysfunction may be associated with depression, loss of self-esteem, poor self-image, increased anxiety or tension with one's sexual partner, and/or fear and anxiety associated with contracting sexually transmitted diseases, including AIDS.
Psychosocial factors are important in all forms of erectile dysfunction. Careful attention to these issues and attempts to relieve sexual anxieties should be a part of the therapeutic intervention for all patients with erectile dysfunction. Psychotherapy and/or behavioral therapy alone may be helpful for some patients in whom no organic cause of erectile dysfunction is detected. Patients who refuse medical and surgical interventions also may be helped by such counseling. After appropriate evaluation to detect and treat coexistent problems such as issues related to the loss of a partner, dysfunctional relationships, psychotic disorders, or alcohol and drug abuse, psychological treatment focuses on decreasing performance anxiety and distractions and on increasing a couple's intimacy and ability to communicate about sex. Education concerning the factors that create normal sexual response and erectile dysfunction can help a couple cope with sexual difficulties. Working with the sexual partner is useful in improving the outcome of therapy. Psychotherapy and behavioral therapy have been reported to relieve depression and anxiety as well as to improve sexual function. However, outcome data of psychological and behavioral therapy have not been quantified, and evaluation of the success of specific techniques used in these treatments is poorly documented. Studies to validate their efficacy are therefore strongly indicated.
Kimberly Hildebrant, ARNP is a board certified Family Nurse practitioner. She graduated with a Bachelor of Science in Nursing from the University of Pittsburgh and a Masters in Nursing from Duquesne University. She has practiced as a nurse practitioner in the field of Infectious Disease as well as HIV for 4 years. She has over 13 years of experience as a critical care nurse. Kimberly is passionate about providing affordable healthcare to all individuals to ensure that all can live their best life. She is an advocate for preventative care and early treatment to avoid lasting illness.
Metabolism (breakdown) of vardenafil can be slowed by aging, liver disease, and concurrent use of certain medications (such as erythromycin [an antibiotic], ketoconazole [Nizoral, a medication for fungal/yeast infections], and protease inhibitors [medications used to treat AIDS]). Slowed breakdown allows vardenafil to accumulate in the body and potentially increase the risk for side effects. Therefore, in men over 65 years of age with liver disease, or who are also taking medication(s) that can slow the breakdown of vardenafil, the doctor will initiate vardenafil at low doses to avoid its accumulation. For example,
The U.S. FDA (Food and Drug Administration) has a list of 29 OTC products that claim to treat erectile dysfunction. Patients should avoid these because many contain harmful ingredients. Other natural or herbal remedies such as DHEA, L-arginine, ginseng, and yohimbe are supplements that have been used but have not been proven safe and effective according to some researchers. Before using such compounds, individuals should consult their doctor. According to some experts, acupuncture does not effectively treat erectile dysfunction. Other home remedies for reducing ED symptoms include diet changes such as eating blueberries and citrus fruits and drinking red wine.
Men with a rare heart condition known as long QT syndrome should not take vardenafil since this may lead to abnormal heart rhythms. The QT interval is the time it takes for the heart's muscle to recover after it has contracted. An electrocardiogram (EKG) measures the QT interval. Some people have longer than normal QT intervals, and they may develop potentially life-threatening abnormal heart rhythms, especially when given certain medications. Men with a family history of long QT syndrome should not take vardenafil, as it is possible to inherit long QT syndrome. Furthermore, vardenafil is not recommended for men who are taking medications that can affect the QT interval such as quinidine (Quinaglute, Quinidex), procainamide (Pronestyl, Procan-SR, Procanbid), amiodarone (Cordarone), and sotalol (Betapace).
Sildenafil is available as oral tablets at doses of 25 mg, 50 mg, and 100 mg. Patients should take sildenafil approximately one hour before sexual activity. In some men, the onset of action of the drug may be as early as 11-20 minutes. It's best for men to take sildenafil on an empty stomach for best results since absorption and effectiveness of sildenafil can be diminished if it is taken shortly after a meal, particularly a meal that is high in fat. Sildenafil and the other PDE5 inhibitors don't cause an immediate erection. Sexual stimulation is necessary for these medications to work.
Erectile dysfunction (ED) is one of the most common conditions affecting middle-aged and older men. Nearly every primary care physician, internist and geriatrician will be called upon to manage this condition or to make referrals to urologists, endocrinologists and cardiologists who will assist in the treatment of ED. This article will briefly discuss the diagnosis and management of ED. In addition, emerging concepts in ED management will be discussed, such as the use of testosterone to treat ED, the role of the endothelium in men with ED and treating the partner of the man with ED. Finally, future potential therapies for ED will be discussed.
Damage to the autonomic pathways innervating the penis may eliminate "psychogenic" erection initiated by the central nervous system. Lesions of the somatic nervous pathways may impair reflexogenic erections and may interrupt tactile sensation needed to maintain psychogenic erections. Spinal cord lesions may produce varying degrees of erectile failure depending on the location and completeness of the lesions. Not only do traumatic lesions affect erectile ability, but disorders leading to peripheral neuropathy may impair neuronal innervation of the penis or of the sensory afferents. The endocrine system itself, particularly the production of androgens, appears to play a role in regulating sexual interest, and may also play a role in erectile function.
Sexual dysfunction is highly prevalent in men and women. In the MMAS, 52% of the respondents reported some degree of erectile difficulty. Complete ED, defined as (1) the total inability to obtain or maintain an erection during sexual stimulation and (2) the absence of nocturnal erections, occurred in 10% of the respondents. Mild and moderate ED occurred in 17% and 25% of responders, respectively. 
There are also alternative treatments, such as using a penis pump or a penile injection. Penis pumps work by creating a vacuum and thereby causing more blood to flow to your penis. Penile injections need to be used shortly before intercourse. They contain a medication which widens your blood vessels. A doctor’s prescription is needed for the injections.
You’ve probably heard of Viagra, but it’s not the only pill for ED. This class of drugs also includes Cialis, Levitra, Staxyn, and Stendra. All work by improving blood flow to the penis during arousal. They're generally taken 30-60 minutes before sexual activity and should not be used more than once a day. Cialis can be taken up to 36 hours before sexual activity and also comes in a lower, daily dose. Staxyn dissolves in the mouth. All require an OK from your doctor first for safety.