Vizarsin
The influence of other drugs on the pharmacokinetics of sildenafil
The metabolism of sildenafil occurs mainly under the influence of cytochrome P450 isoenzymes - CYP3A4 (main pathway) and CYP2C9 (minor pathway), therefore inhibitors of these isoenzymes can reduce the clearance of sildenafil, and inducers, accordingly, increase the clearance of sildenafil.
Concomitant use of CYP3A4 isoenzyme inhibitors (such as ketoconazole, erythromycin, pimetidine) and sildenafil reduces its clearance.
Ritonavir increases the AUC of sildenafil by 11 times; simultaneous use of these drugs is not recommended. If simultaneous use with ritonavir is necessary, the maximum single dose of Vizarsin® should not exceed 25 mg, and the frequency of use should be 1 time every 48 hours.
With the simultaneous use of sildenafil (100 mg 1 time / day) and the HIV protease inhibitor and inhibitor of the CYP3A4 isoenzyme saquinavir, while achieving a constant concentration of saquinavir in the blood (1200 mg 3 times / day), Cmax of sildenafil increases by 140%, and AUC - by 210%. Sildenafil has no effect on the pharmacokinetics of saquinavir. Stronger inhibitors of the CYP3A4 isoenzyme, such as ketoconazole and itraconazole, presumably may cause more pronounced changes in the pharmacokinetics of sildenafil.
The use of sildenafil at a dose of 100 mg 1 time / day simultaneously with erythromycin, a specific CYP3A4 inhibitor, against the background of achieving a constant concentration of erythromycin in the blood (500 mg 2 times / day for 5 days), leads to an increase in the AUC of sildenafil by 182%. In healthy male volunteers, azithromycin (500 mg/day for 3 days) did not affect the AUC, Cmax, Tmax, elimination rate constant, and T1/2 of sildenafil or its main circulating metabolite. Cimetidine (800 mg), a nonspecific inhibitor of CYP3A4, when coadministered with sildenafil (50 mg) to healthy volunteers caused an increase in plasma sildenafil concentrations by 56%.
Grapefruit juice, a weak inhibitor of CYP3A4, may moderately increase plasma concentrations of sildenafil.
Single use of antacids (magnesium hydroxide/aluminum hydroxide) does not affect the bioavailability of sildenafil.
Although special pharmacokinetic studies have not been conducted with all drugs, a population pharmacokinetic analysis did not reveal changes in the pharmacokinetics of sildenafil when used simultaneously with such inhibitors of the CYP2C9 isoenzyme as tolbutamide, warfarin, phenytoin, with inhibitors of the CYP2D6 isoenzyme (selective serotonin reuptake inhibitors and tricyclic antidepressants), thiazide and similar diuretics, loop and potassium-sparing diuretics, ACE inhibitors, calcium channel blockers, beta-blockers or CYP450 inducers (such as rifampicin, barbiturates).
Nicorandil is a hybrid of a nitrate and a potassium channel activator. Due to the presence of a nitrate component, it may interact undesirably with sildenafil.
Effect of sildenafil on other drugs
Sildenafil is a weak inhibitor of cytochrome P450 isoenzymes 1A2, 2C9, 2C19, 2D6, 2E1 and 3A4 (IC50 >150 µmol). When sildenafil is used in recommended doses, its Cmax in blood plasma is about 1 µmol, so it is unlikely that Vizarsin® can affect the clearance of substrates of these isoenzymes.
There is no data on the interaction of sildenafil with nonspecific phosphodiesterase inhibitors such as theophylline or dipyridamole.
Given the known effect of sildenafil on NO/cGMP, it may enhance the hypotensive effect of nitrates, therefore its simultaneous use with nitric oxide donors or nitrates in any dosage form is contraindicated.
Concomitant use of sildenafil and alpha-blockers may lead to symptomatic hypotension in selected susceptible patients. Arterial hypotension most often develops 4 hours after taking sildenafil. In three specific drug interaction studies, hemodynamically stable benign prostatic hyperplasia (BPH) patients receiving doxazosin (4 mg and 8 mg) were co-administered sildenafil (25 mg, 50 mg, or 100 mg). In all three studies, there were mean additional reductions in supine BP of 7/7 mmHg, 9/5 mmHg, and 8/4 mmHg. and an additional reduction in blood pressure in the standing position by 6/6 mm Hg, 11/4 mm Hg, and 4/5 mm Hg, respectively. With the simultaneous use of sildenafil and doxazosin in patients with stable hemodynamics while taking doxazosin, rare cases of the development of symptomatic postural hypotension have been observed. In these described cases, dizziness or a feeling of lightness developed, but without the development of fainting conditions. To reduce the likelihood of developing orthostatic hypotension, it is necessary to achieve a stable state on alpha-blocker therapy before starting the use of sildenafil.
No significant interaction was observed with simultaneous use of sildenafil (at a dose of 50 mg) and tolbutamide (at a dose of 250 mg) or warfarin (at a dose of 40 mg), which are metabolized with the participation of CYP2C9.
Sildenafil (at a dose of 50 mg) does not potentiate the increase in bleeding time caused by acetylsalicylic acid (at a dose of 150 mg).
Sildenafil (at a dose of 50 mg) does not potentiate the hypotensive effect of ethanol in healthy volunteers at a maximum ethanol blood level of 80 mg/dL.
A synthesis of available data on the following drugs: diuretics, beta-blockers, ACE inhibitors, angiotensin II receptor blockers, vasodilators and centrally acting antihypertensives, adrenergic neuron blockers, calcium channel blockers and alpha-adrenergic blockers, did not reveal differences in the profile of adverse reactions among patients taking sildenafil or placebo concomitantly. In a special study, sildenafil (at a dose of 100 mg) was used simultaneously with amlodipine in patients with arterial hypertension, and additionally reduced systolic blood pressure in the supine position by an average of 8 mm Hg, and diastolic blood pressure by 7 mm Hg. Art. This additional reduction in blood pressure was the same as that observed with sildenafil alone in healthy volunteers.
Vizarsin, 12 pcs., 100 mg, film-coated tablets
To diagnose erectile dysfunction, determine its possible causes and select adequate treatment, it is necessary to obtain a complete medical history and conduct a thorough physical examination. Treatments for erectile dysfunction should be used with caution in patients with anatomical deformation of the penis (angulation, cavernous fibrosis, Peyronie's disease) or in patients with risk factors for priapism (sickle cell anemia, multiple myeloma, leukemia) (see Caution) .
).
During post-marketing studies, cases of prolonged erection and priapism have been reported. If an erection persists for more than 4 hours, you should immediately seek medical help. If treatment for priapism is not carried out immediately, it can lead to damage to the tissue of the penis and irreversible loss of potency. Medicines intended to treat erectile dysfunction should not be used by men for whom sexual activity is undesirable.
Sexual activity poses a certain risk in the presence of heart disease, therefore, before starting any therapy for erectile dysfunction, the doctor should refer the patient to an examination of the cardiovascular system. Sexual activity is undesirable in patients with heart failure, unstable angina, myocardial infarction or stroke in the last 6 months, life-threatening arrhythmias, arterial hypertension (BP >170/100 mm Hg) or arterial hypotension (BP <90/50 mm Hg . Art.) (see With caution
). Clinical studies have shown no difference in the incidence of myocardial infarction (1.1 per 100 people per year) or the incidence of cardiovascular mortality (0.3 per 100 people per year) in patients treated with sildenafil compared with patients treated with sildenafil. those receiving placebo.
Cardiovascular complications.
During post-marketing use of sildenafil for the treatment of erectile dysfunction, adverse events such as severe cardiovascular complications (including myocardial infarction, unstable angina, sudden cardiac death, ventricular arrhythmia, hemorrhagic stroke, transient ischemic attack, hypertension and hypotension) have been reported ), which had a temporary association with the use of sildenafil. Most of these patients, but not all of them, had risk factors for cardiovascular complications. Many of these adverse events occurred shortly after sexual activity, and some of them occurred after taking sildenafil without subsequent sexual activity. It is not possible to establish a direct connection between the observed adverse events and these or other factors.
Arterial hypotension.
Sildenafil has a systemic vasodilating effect, leading to a transient decrease in blood pressure, which is not a clinically significant phenomenon and does not lead to any consequences in most patients. However, before prescribing Vizarsin®, the physician must carefully assess the risk of possible undesirable manifestations of the vasodilating effect in patients with relevant diseases, especially against the background of sexual activity.
Increased susceptibility to vasodilators is observed in patients with obstruction of the left ventricular outflow tract (aortic stenosis, hypertrophic obstructive cardiomyopathy), as well as the rare multiple system atrophy syndrome, manifested by severe dysregulation of blood pressure from the autonomic nervous system.
Since the simultaneous use of sildenafil and α-blockers can lead to symptomatic arterial hypotension in some sensitive patients, Vizarsin® should be used with caution in patients taking α-blockers (see “Interactions”).
To minimize the risk of developing orthostatic hypotension in patients taking α-blockers, Vizarsin® should be started only after hemodynamic parameters have stabilized in these patients. You should also consider the advisability of reducing the initial dose of Vizarsin® (see “Dosage and Administration”). The physician should inform patients about what actions to take if symptoms of orthostatic hypotension occur.
Visual impairment.
In rare cases, during post-registration use of all PDE-5 inhibitors, incl. sildenafil, reported NPINSID, a rare disease and cause of decreased or loss of vision. Most of these patients had risk factors, including a decreased papilledema/disc ratio (“congestive disc”), age over 50 years, diabetes mellitus, hypertension, coronary artery disease, hyperlipidemia, and smoking. An observational study assessed whether recent use of the PDE5 inhibitor class of drugs was associated with acute onset of NPINSID. The results indicate an approximately two-fold increase in the risk of NPINI within 5 T1/2 after use of a PDE5 inhibitor. Published literature estimates the annual incidence of NPINSID to be 2.5–11.8 cases per 100,000 men aged ≥50 years in the general population. In case of sudden loss of vision, patients should be advised to stop sildenafil therapy and consult a doctor immediately. Individuals who have already had a case of NPIND have an increased risk of recurrent NPIND. Therefore, the physician should discuss this risk with such patients, as well as the potential for adverse effects from PDE5 inhibitors. PDE-5 inhibitors, incl. sildenafil should be used with caution in such patients and only in situations where the expected benefit outweighs the risk.
A small number of patients with hereditary retinitis pigmentosa have genetically determined dysfunction of the retinal PDE. There is no information on the safety of using sildenafil in patients with retinitis pigmentosa, so Vizarsin® should be used with caution (see Precautions
).
Hearing impairment.
Some post-marketing studies have reported cases of sudden deterioration or loss of hearing associated with all PDE5 inhibitors, including sildenafil.
Most of these patients had risk factors for sudden deterioration or loss of hearing. A cause-and-effect relationship between the use of PDE5 inhibitors and sudden hearing loss or deterioration has not been established. If there is a sudden deterioration in hearing or hearing loss while taking Vizarsin®, you should immediately consult your doctor.
Bleeding.
Sildenafil enhances the antiplatelet effect of sodium nitroprusside, an NO donor, on human platelets in
vitro.
There are no data on the safety of sildenafil in patients with a tendency to bleeding or exacerbation of gastric and duodenal ulcers, so Vizarsin should be used with caution in such patients (see Caution
)
. The incidence of epistaxis in patients with pulmonary hypertension associated with diffuse connective tissue diseases was higher (sildenafil 12.9, placebo 0%) than in patients with primary pulmonary hypertension (sildenafil 3, placebo 2.4%). Patients receiving sildenafil in combination with a vitamin K antagonist had a higher incidence of epistaxis (8.8%) than patients not taking a vitamin K antagonist (1.7%).
Simultaneous use with other drugs for the treatment of erectile dysfunction. The safety and effectiveness of Vizarsin® concomitantly with other PDE5 inhibitors or other drugs for the treatment of pulmonary hypertension containing sildenafil, or other drugs for the treatment of erectile dysfunction, therefore the use of such combinations is not recommended (see “Contraindications”).
Impact on the ability to perform potentially hazardous activities that require special attention and quick reactions (for example, driving, working with moving mechanisms).
Since when taking sildenafil, it is possible to develop dizziness, decrease in blood pressure, develop chromatopsia, blurred vision, etc. side effects, caution should be exercised when driving vehicles and engaging in other potentially hazardous activities that require increased concentration and speed of psychomotor reactions. You should also be careful about the individual effect of Vizarsin® in these situations, especially at the beginning of treatment and when changing the dosage regimen.
Efficacy and safety of sildenafil citrate in the treatment of erectile dysfunction
Sildenafil - the first PDE-5 inhibitor
PDE5 inhibitors are highly effective and safe oral medications for the treatment of ED and are recommended as first-line therapy [1].
The number of patients taking these drugs continues to increase in parallel with the increasing prevalence of ED. In 1998, the drug sildenafil was approved for clinical use. This moment became not just the starting point for the existence of another drug on the pharmacological market. It turned out to be the beginning of a new era in the field of sexual medicine, marked by a real breakthrough in the fundamental and clinical spheres, as well as in public perception of sexual pathology.
Sildenafil became the first effective and safe oral drug for the treatment of ED. The history of the discovery of sildenafil was preceded by the accumulation of knowledge about the role of nitric oxide in ensuring the normal functional state of the cardiovascular system, which was initiated by RR Furchgott and JV Zawadski [2]. However, today's use of the drug as an ED therapy is an example of how a chance observation can have a huge impact on the course of scientific progress. During clinical trials of the antianginal properties of sildenafil, researchers noted that although taking the drug is not accompanied by a significant clinical improvement in angina, in many patients it leads to the development of a kind of “side effect”, which consists in improving erectile function. This observation led to further study of the possibility of using this substance in the treatment of ED.
The discovery of sildenafil, a selective PDE5 inhibitor, led to numerous fundamental studies showing that this type of enzyme dominates in cavernous tissue, which ensures the selectivity of the drug. It should be noted that these studies also made it possible to clarify the mechanisms of action of other drugs that have been used in clinical practice for a long time, in particular papaverine and prostaglandin E1 [3], and significantly expand knowledge about the mechanism of erection and its disorders leading to ED.
The emergence of sildenafil also had a great impact on clinical research in the field of sexual medicine. In recent years, terminology has been clarified and new definitions of various forms of sexual disorders have been developed. Clinical trials of sildenafil have stimulated the creation of new diaries and questionnaires to assess the state of male sexual function. Analysis of demographic indicators of participants in large-scale clinical trials has revealed risk factors for ED, which, in turn, has contributed to the understanding of its pathogenesis.
The appearance of sildenafil had a huge public outcry. A large number of patients with ED, who had not previously consulted a doctor, received hope for the restoration of sexual function, and to date, millions of men around the world have returned to normal sexual life thanks to taking this drug.
The dose of the drug is selected by titration, starting from 50 mg, followed by a dose change (either decreasing to 25 mg or increasing to 100 mg) depending on the effect and tolerability. Sildenafil is taken 1 time per day, 1 hour before intended sexual intercourse. The effect of the drug begins 40-60 minutes after administration and lasts for 3-5 hours [3]. It is important to note that taking the drug by itself does not lead to an erection and sexual stimulation is necessary for its effect to begin.
Sildenafil is contraindicated in patients taking nitrates, patients with hypotension, severe hepatic impairment (the drug is metabolized by hepatic cytochrome P450 3A4) and pigmentary retinopathy [20].
The clinical effectiveness of sildenafil has been assessed in numerous studies conducted around the world. S.S. Carson et al. combined data obtained from 11 double-blind, placebo-controlled studies, including a total of almost 3 thousand patients with ED. After 12 weeks after starting to take the drug, an improvement in erection was noted by 76% of men receiving sildenafil and 22% of those receiving placebo, while the percentage of successful attempts at sexual intercourse was 66 and 26% in groups 1 and 2, respectively. The effectiveness of various doses of sildenafil was 65% for 25 mg, 74% for 50 mg, 82% for 100 mg. The high effectiveness of sildenafil was noted in different age groups. Thus, among patients younger and older than 65 years, the effectiveness of sildenafil was 77.6 and 69.2%, respectively. A significantly higher effectiveness of sildenafil compared to that of placebo also occurred in patients with ED of varying severity and different etiologies [4].
The use of sildenafil in special categories of patients with ED
As is known, arterial hypertension (AH) is one of the risk factors for ED. Although sildenafil has some antihypertensive effects, the drug is safe in patients with hypertension, both those receiving and not receiving antihypertensive drugs [5, 6]. The effectiveness of sildenafil in patients with ED and hypertension is high. Among patients with hypertension of various origins, taking placebo and sildenafil was accompanied by an improvement in erection in 18 and 70% of patients, respectively. Among men taking 2 or more antihypertensive drugs, these figures were 17.6 and 71% [6].
Another well-known risk factor for ED is smoking. The effectiveness of sildenafil among smokers was not inferior to that among non-smokers (80 and 74%, respectively) [4].
Many epidemiological studies have shown that depression is the second most common cause of ED after cardiovascular risk factors. In addition, the presence of ED aggravates depressive symptoms. Treatment with sildenafil was not only highly effective in patients with depression in terms of improving erectile function, but was also accompanied by a decrease in the severity of depressive symptoms [7].
Various neurological diseases, as mentioned above, can also cause the development of ED. According to studies, the effectiveness of sildenafil among patients with parkinsonism, multiple sclerosis and spinal cord injuries exceeds 80%, which corresponds to data obtained in the general population of patients with ED [8].
Special groups of patients with ED that is difficult to treat are patients with diabetes mellitus (DM) and patients who have undergone radical prostatectomy (RP).
In patients with diabetes, the effectiveness of sildenafil depends on the severity of the underlying disease and the presence of its complications. Thus, in the study by S.S. Carson et al. among patients with diabetes without complications, 8% of patients receiving placebo and 69% of those receiving sildenafil noted improved erection. In the presence of 1 complication, these figures were 12 and 43%, and in the presence of 2 complications, 10 and 43%, respectively. In all groups, the effectiveness of sildenafil was significantly higher than that of placebo [4].
The effectiveness of ED treatment after RP is determined by a number of factors. According to R. Raina et al., treatment with sildenafil was effective in 71.7% of patients after bilateral nerve-sparing RP, in 50% after unilateral nerve-sparing RP, and only in 15% of patients with ED after non-nerve-sparing surgery [9].
In addition, a feature of the course of ED in such patients is the possibility of progressive improvement of erection for up to 4 years after surgery, and therefore the ineffectiveness of a particular treatment method can be finally judged only several years after surgery. This is confirmed by data from a survey of 316 patients with ED after RP, which in 95% of cases was of a bilateral nerve-sparing nature. The effectiveness of sildenafil was 26% during the first 6 months, 36% in the period from 6 to 12 months, 50% from 12 to 18 months, 60% from 18 to 24 months. after surgery [10].
Analysis of the effectiveness and tolerability of sildenafil
Despite the high effectiveness of sildenafil, there remains a certain number of patients in whom taking this drug does not lead to an improvement in erection. In many cases, this is due to improper medication administration [11]. Patients, especially at the beginning of treatment, should be advised to take sildenafil on an empty stomach at least 30 minutes before the start of sexual activity [21]. It is also important to explain to patients that the effect of the drug develops only against the background of adequate sexual arousal and largely depends on it. In many cases, treatment should be started with 100 mg, which will allow for maximum response early in treatment and give patients confidence in its success [21-23]. In addition, studies have shown that in some patients the maximum effect of sildenafil is achieved by 6-8 doses, and therefore in many patients the final assessment of the effectiveness of the drug should be carried out after several attempts at its use [24, 37, 38].
Noteworthy is the work of A. Eisenhardt et al., who found that the clinical effectiveness of sildenafil depends on genetic factors. When analyzing the relationship between the GNB3 C825T gene polymorphism and ACE I/D, it was found that in the group of carriers of the GNB3 825C allele, sildenafil was effective in only 50% of men, while among those with the TT genotype this figure exceeded 90%. Similar results were obtained regarding the ACE I/D polymorphism: among carriers of the ACE D allele, the effectiveness of sildenafil did not exceed 50%, while in men with genotype II it was 75% [12].
The long-term effectiveness of sildenafil was also studied by Montorsi et al., who surveyed 2618 patients taking the drug for 3 years. Overall, 96% of these patients were satisfied with the treatment, and only 1.6% discontinued it due to low effectiveness [25]. The remaining 2.4% of patients stopped taking the drug for other reasons. Laboratory studies have not confirmed the existence of a tachyphylaxis effect when taking sildenafil [13].
An important characteristic of any pharmacological drug is its side effects. The most common side effects when taking sildenafil include headache (7%), facial flushing (7%), dizziness (2%), dyspepsia (1.8%), nasal congestion (1.4%) and visual disturbances. , usually in the form of blue coloring of objects (1.2%) [26].
It should also be noted that the frequency of side effects decreases as the drug is taken. Thus, in the study by S.S. Carson, the frequency of all side effects, except for visual impairment and dyspeptic disorders, decreased during the period of taking the drug. Headaches at the beginning of the study were noted by 7% of patients with ED, and after 16 weeks. - less than 1%, the frequency of dizziness also decreased from 7% to less than 1%, and nasal congestion - from 1.4% to less than 0.5% [14]. An important circumstance is also that 2/3 of patients during this study increased the dose of sildenafil. Thus, with long-term use, the frequency of most side effects of sildenafil does not exceed that of placebo.
There is growing interest in the possibility of using sildenafil for various diseases in addition to ED. In a study by K. Sairam et al. The effect of sildenafil on the severity of urinary disorders in patients with ED was assessed. After 1 and 3 months. after the start of treatment, there was a significant decrease in the severity of symptoms of lower urinary tract dysfunction, which was accompanied by an improvement in erectile function [15].
Taking sildenafil leads to an improvement in the condition of patients with primary and secondary pulmonary hypertension [27, 28]. Another possible direction for future research with sildenafil is the use of this drug in the treatment of endothelial dysfunction [29-31].
Safety of sexual activity in patients with cardiovascular diseases
Sexual intercourse in most cases is accompanied by physical activity. This makes some people, primarily men suffering from cardiovascular diseases and their partners, worry about the possibility of developing various complications due to sexual activity, which can lead to limitation or complete abandonment of it. These fears are reinforced by stories of famous people whose deaths allegedly occurred during sexual intercourse. At the same time, research data show that the risk of cardiovascular complications in patients suffering from cardiac pathology during and immediately after sexual activity, although it exists, is relatively low. For example, the risk of developing myocardial infarction in a healthy 50-year-old man within 1 year is 1%. As a result of sexual activity, this risk increases to 1.01% in a healthy man and to 1.1% in a man with a confirmed diagnosis of coronary heart disease (CHD) [16]. According to these data, the absolute risk of developing cardiovascular complications for a healthy man is 1 chance in 1 million. This figure increases to 2 chances in 1 million within 2 hours after intercourse for a healthy man and to 20 chances in 1 million for a man. suffering from coronary artery disease [33].
During sexual intercourse, on average, a man’s maximum heart rate reaches 120-130 beats/min, while systolic blood pressure rises to 150-180 mm Hg. Art. [34]. These indicators take place within only 3-5 minutes with an average duration of sexual intercourse from 5 to 15 minutes. The level of stress on the heart is usually expressed in metabolic equivalents (METs). One MET corresponds to an energy requirement expressed in resting oxygen consumption, which is 3.5 ml oxygen/1 kg body weight per minute. In most cases, during sexual activity with a usual partner, the load is 2-3 METs (with a maximum value of 5-6 METs), depending on the intensity and position. This corresponds to walking 1.5 km in 20 minutes or climbing 20 steps in 10 seconds. All of the above indicates that sexual activity in familiar conditions and with a familiar partner does not pose a greater danger for both a healthy man and a patient with coronary artery disease than various forms of everyday physical activity.
In order to standardize the assessment of cardiac risk in men with coronary artery disease who resume sexual activity, several recommendations have been created, the most widely known of which are the Princeton recommendations [16]. In accordance with these recommendations, all patients are divided into 3 risk groups depending on the number of risk factors for coronary artery disease they have and/or the severity of cardiovascular pathology. Most patients are at low risk and do not require additional cardiac examination before resuming sexual activity, which does not pose a risk to them. Patients from the average risk group require additional cardiac examination, after which they are classified as low or high risk. Patients at high risk have severe cardiovascular pathology, accompanied by severe heart failure. These patients require specialized treatment, after which the question of the degree of danger of sexual activity for them is again considered [16].
Changes in cavernous electrical activity and hemodynamics of the penis during treatment with sildenafil
To assess the effect of sildenafil on cavernous electrical activity and hemodynamics of the penis, we conducted our own study [17, 35, 36]. 291 patients with ED of various etiologies aged 21-73 years (average 59.1±14.7 years) after examination, which included a questionnaire to assess male sexual health (International Index of Erectile Function (IIEF)), pharmacodopplerography (FDG) and electromyography (EMG) of the penis were divided into groups comparable in age, severity, suspected etiology and pathogenesis of ED [17]. The sildenafil group included 81 patients who took 25-100 mg of sildenafil 1 hour before sexual intercourse for 6 months. The control examination, carried out monthly, included a survey of IIEF, FDG and EMG of the penis.
The IIEF “erectile function” indicator during treatment with sildenafil increased by 61.7% (p
Thus, according to the results of FDG, sildenafil affects both arterial and venous blood flow in the penis, which makes it primarily indicated for vasculogenic ED. EMG showed an improvement in cavernous electrical activity during treatment with sildenafil, apparently due to improved hemodynamics of the penis and oxygenation of cavernous tissue. In addition, according to the results of the IIEF survey, sildenafil provides a rapid, lasting rehabilitation effect.
New sildenafil drugs
The pharmaceutical market is represented not only by the original drug sildenafil, but also by so-called generics, one of which is the drug Dynamico.
Patient preferences when choosing drugs are influenced by many factors, including effectiveness, quality of erections, durability of improvement, speed of onset and duration of action of the drug, as well as the range of side effects [18]. Efficacy and safety are the most important factors determining patient preferences. The research results show that the clinical effectiveness of Dynamico is comparable to that of the original drug. In addition, the incidence of side effects (headache, skin flushing) was even lower than that of other sildenafil drugs [17]. This is very important for those patients who experienced adverse events during therapy. The drug Dynamico provides high-quality erection with a minimum of side effects and does not cause addiction or dependence [17, 19].
The appearance on the market of new effective and safe drugs that can improve the quality of life of patients with ED makes the therapeutic arsenal of a urologist-andrologist more diverse and allows an increase in the number of patients satisfied with such treatment.
Conclusion
The clinical effectiveness of sildenafil has been assessed in a large number of studies conducted in many countries around the world. Taking the drug leads to an improvement in erectile function in patients of different ages, regardless of the etiology, severity and duration of ED. The effectiveness of the drug is long-term. Sildenafil affects both arterial and venous blood flow in the penis, so the drug is also indicated for vasculogenic ED. When treated with sildenafil, an improvement in cavernous electrical activity is observed, which justifies its use in neurogenic ED. According to the results of the IIEF survey, sildenafil provides a rapid and lasting therapeutic effect. The effectiveness and safety of sildenafil are assessed as good. With both short-term and long-term use, sildenafil does not cause dependence or addiction.
