Erection is a vascular phenomenon associated with hormonal and nervous control, including arterial dilation, relaxation of smooth trabecular muscles.
Erectile dysfunction (ED) is the inability to achieve and maintain an erection sufficient for sexual intercourse. This condition does not pose a danger to life, however, it significantly affects the quality of life of the patient and those around him and affects the physical and mental components of health. Among men of all ages, the prevalence of ED is 10%, and it is estimated that by 2025 the number of people suffering from ED will increase to 400 million. The largest increase is expected in developed countries.
Risk factors for the development of ED can be vascular (≈20%), endocrine (≈10%), neurological diseases (≈20%), alcohol abuse (≈20%), side effects of drugs (≈10%), psychological reasons (≈ 20%), cardiovascular and systemic diseases (chronic renal failure, diabetes mellitus) and their combinations. ED of organic genesis in 50–80% of men is caused by insufficient arterial blood supply to the penis of various origins. The likelihood that a first-time ED patient has coronary artery disease is estimated to be 40%, and many of these patients are treated with nitrates. A multicenter, randomized, open-label study compared obese men with moderate ED who played sports for 2 years and lost weight with a control group in which patients had the opportunity to change their diet or exercise. The significant improvement in erectile function in the lifestyle group was accompanied by an optimization of the body mass index.
The development of diagnostic and treatment methods, fundamental research in physiology, pharmacology and other disciplines made it possible to get closer to understanding the mechanism of erection and its disorders. At the moment of adequate sexual stimulation, relaxation of the smooth muscles of the corpora cavernosa occurs. At the same time, nitric oxide is released from the presynaptic endings and an increase in the blood filling of the corpora cavernosa occurs. Due to their enlargement, the veins are pressed against the tunica albuginea, which leads to the cessation of venous outflow and the achievement of an erection sufficient for penetration.
Currently, it is believed that nitric oxide secreted by non-cholinergic and non-adrenergic nerve endings, the synthesis of which occurs as a result of the action of neuronal NO-synthase, plays a key role in “triggering” penile erection. The physiological antagonist of NO is a vasoconstrictor with anti-inflammatory, mitogenic and profibrotic effects, endothelin-1. Apparently, the interaction of these factors is a universal, general biological process.
Modern ideas about the physiology of erection have become the basis for various methods of treating ED. Previously used reconstructive vascular surgical methods of treatment did not give effective results.
In order to objectify the various symptoms of ED, questionnaires of patients using questionnaires have become widespread. This method allows you to evaluate all components of sexual function and determine the effectiveness of the treatment methods used.
It has been suggested that arteriogenic ED in some patients is based not on organic, but on functional, potentially reversible damage to the arteries – endothelial dysfunction, which is currently considered as a functional stage in the development of atherosclerosis. Currently, the term “endothelial dysfunction” is commonly used to mean a decrease in endothelium-dependent relaxation of smooth muscle cells. A technique for assessing postocclusal changes in the diameter of the cavernous arteries is proposed. The regularity revealed in the analysis of the results, consisting in the presence of signs of endothelial dysfunction in all patients with values less than 50%, indicating arteriogenic ED, confirms the presence of systemic vascular diseases, which emphasizes the importance of more active detection of ED by doctors of various specialties.
The intracavernous injection test with vasoactive drugs does not provide complete information about the state of the vessels. A positive result is considered to be a rigid erection that occurs 10 minutes after intracavernous injection and lasts for 30 minutes. Such a response to intracavernous administration of a vasoactive drug indicates a functional, but not necessarily physiological, erection, since the latter can occur against a background of venous insufficiency. A positive test result indicates that the intracavernous injection technique is effective for the patient. This test is not sufficient to establish a diagnosis, and a duplex ultrasound of the penile arteries must be performed.
If the maximum blood flow velocity is more than 30 cm / s, and the resistance index is above 0.8, then such indicators are considered normal. With normal results of duplex examination, further examination of the vascular system is not required.
The primary goal of treating ED is to determine the etiology of the disease and, if possible, treat it rather than treat the symptoms. These can be recommendations regarding the patient’s lifestyle and the possibility of changing them. Significant progress in understanding the peripheral physiology of penile erection has led to the greatest advances in the pharmacological treatment of ED through the use of phosphodiesterase type 5 (PDE5) inhibitors. The enzyme PDE-5 hydrolyzes cyclic guanosine monophosphate in the cavernous tissue of the penis. Suppression of PDE5 stimulates blood flow in the penis, which leads to relaxation of smooth muscles, dilation of blood vessels and erections.
In 1998, the “ideal” drug for treating ED was described. Such a drug should be effective, safe, quickly manifest its effect and act for a long time. The effect of the drug should not be affected by the intake of food, alcohol or other drugs, it should be suitable for periodic intake on demand and ensure spontaneous sex life.
Sildenafil citrate is the first drug to be used to treat ED. The effect of sildenafil appears 30-60 minutes after administration. Heavy fatty food before taking the drug reduces its effectiveness, slowing down absorption. The effect of the drug can last up to 12 hours. Adverse events (headache (12.8%), flushing (10.4%), dyspepsia (4.6%), nasal congestion (1.1%), dizziness (1, 2%), visual impairment (1.9%)), as a rule, are insignificant and stop themselves. The percentage of drug withdrawals due to complications is comparable to that of placebo. After 24 weeks, according to a study in which the dose was effective, there was an improvement in erection in 56, 77 and 84% of men taking 25, 50 and 100 mg of sildenafil, respectively, compared with 25% in the placebo group.
A common, effective, affordable and convenient form of sildenafil is Tornetis®. Its use statistically significantly improves the International Index of Erectile Function (IIEF) scores, the sex profile, and treatment satisfaction.
The uniqueness of Tornetis® is not limited to the ability to provide a pronounced functional effect in the form of erection restoration. The anti-stress properties of the drug are of a certain importance – as it were, the mechanism of natural limitation of the adrenergic response in extreme situations is supplemented, which is the essence of the second (protective) action. Rehabilitation of sexual function is achieved by a unique mechanism for individual selection of the dose of the drug.
Sildenafil has been shown to be effective in almost every ED group. Among patients with diabetes, 66% reported an improvement in erection, 63% reported successful attempts to have sexual intercourse (28.6 and 33%, respectively, in the placebo group).
Patients choose the dose of sildenafil contained in Tornetis®, depending on their dynamic stereotype, since the needs of men and their partners have become much more than just achieving an erection. The choice of dosage and the frequency of taking the drug depend on the frequency of sexual intercourse and the patient’s personal perception of the drug. Patients need to plan for the duration of the effect. Objective examination data allow us to have good reasons for selecting the optimal dose of the drug.
A prerequisite for choosing the dosage of Tornetis® is the possibility of individual selection of the dose. Despite the effectiveness of PDE-5 inhibitors, most patients want to reduce their intake of drugs that improve erection. The prescribing physician should also be able to titrate the dose based on its effectiveness. Sildenafil is the drug with the most experience in clinical practice. The effectiveness of sildenafil has been proven in various categories of patients. Along with these properties, patients taking Tornetis® have a unique opportunity to independently select the dosage of the drug. At the touch of a finger, a 100 mg tablet can be divided into 4 portions of exactly 25 mg each. This allows you to accurately select the dose and avoid unnecessary intake of an increased dose.
Doppler study of the cavernous arteries is based on anatomical data and modern ideas about the physiology of erection. At rest, the smooth muscles of the cavernous bodies of the penis are in a state of complete contraction, peripheral resistance is high, and as a result, moderate arterial blood flow is noted. At the beginning of an erection, the smooth muscles of the corpus cavernosum relaxes due to a neurotransmitter response, the resistance of the corpora cavernosa decreases, and the supplying arteries expand. This leads to increased arterial blood flow and an increase in penile volume (swelling phase). Since the dense tunica albuginea is slightly stretchable, due to the increase in blood volume, the venules are compressed between the filled sinusoids and the membrane. Venous outflow stops, the penis becomes hard.