Levitra 20mg

The total clearance of vardenafil is 56 l / h, the final T1/2 is about 4-5 hours. After oral administration, vardenafil in the form of metabolites is excreted mainly by the gastrointestinal tract (91-95% of the dose), to a lesser extent by the kidneys (2-6% of the dose).

Elderly patients (over 65 years old)

In healthy older men (over 65 years of age) compared with young men (under 45 years of age), the hepatic clearance of vardenafil is reduced. On average, in elderly patients taking vardenafil, the ACC increases by 52%. However, there is no difference in the efficacy and safety levitra 20mg of the drug in elderly and young patients.

Kidney failure

In patients with mild (creatinine clearance (CC) > 50-80 ml/min) and moderate (CC > 30-50 ml/min) degree of renal dysfunction, the pharmacokinetic parameters of vardenafil are comparable to those of healthy men.

In severe renal impairment (CC < 30 ml / min), the average value of the ACC index increases by 21%, and the Cmax decreases by 23%. There is no significant correlation between creatinine clearance and the concentration of vardenafil in plasma (ACC and Cmax). The pharmacokinetics of vardenafil has not been studied in patients undergoing hemodialysis.

Impaired liver function

In patients with mild to moderate hepatic impairment, the clearance of vardenafil decreases in proportion to the degree of impairment.

With mild liver dysfunction (class A according to the Child-Pugh classification), there is an increase in PPK and Cmax by 1.2 times (PPK by 17%, Cmax by 22%), and with moderate (class B according to the Child-Pugh classification) - by 2.6 (160%) and 2.3 (130%) times, respectively. The pharmacokinetics of vardenafil has not been studied in patients with severe hepatic impairment (Child-Pugh class C).

Pharmacodynamics

  • Erection of the penis is a hemodynamic process, which is based on the relaxation of the smooth muscles of the cavernous bodies and arterioles located in it. During sexual stimulation, nitric oxide (NO) is released from the nerve endings of the cavernous bodies, activating the enzyme guanylate cyclase, which leads to an increase in the content of cyclic guanosine monophosphate (cGMP) in the cavernous bodies. As a result, the smooth muscles of the cavernous bodies relax, which contributes to an increase in blood flow to the penis. The level of cGMP is regulated, on the one hand, by the synthesis of guanylate cyclase, and on the other hand, by the cleavage of cGMP by hydrolysis by phosphodiesterases (PDE). The most well-known PDE is cGMP-specific phosphodiesterase type 5 (PDE-5).
  • By blocking PDE-5, which is involved in the cleavage of cGMP, vardenafil thereby enhances the local action of endogenous nitric oxide (N0) in the cavernous bodies during sexual stimulation. An increase in the level of cGMP due to inhibition of PDE-5 leads to relaxation of the smooth muscles of the cavernous bodies and an increase in blood flow to them.

This effect determines the ability of Levitra® to enhance the natural response to sexual stimulation.

Vardenafil is a powerful and highly selective inhibitor of PDE-5 (the average inhibitory concentration relative to PDE-5 is 0.7 nM). The inhibitory activity of vardenafil on PDE-5 is more pronounced than on other known PDEs (15 times more than on PDE-6, 130 times more than on PDE-1, 300 times more than on PDE-11 and 1000 times more than on PDE-2,3,4,7,8,9,10).

Taking vardenafil at a dose of 20 mg can cause an erection (sufficient for penetration) after 15 minutes. A complete response is achieved in 25 minutes.

Indications for the use of Levitra

Erectile dysfunction (inability to achieve and maintain an erection necessary for sexual intercourse).

Recommended

  • Hypersensitivity to any of the components of the drug;
  • simultaneous use with nitrates or drugs that are nitric oxide donors;
  • simultaneous use with riociguate, a stimulant of soluble guanylate cyclase;
  • concomitant use with moderately active or potent CYP3A4 inhibitors, such as erythromycin, ketoconazole (at a dose of more than 200 mg), itraconazole (at a dose of more than 200 mg), clarithromycin, indinavir and ritonavir;
  • severe heart failure (III-IV functional class);
  • in patients with a history of unilateral vision loss due to nonarteritic anterior ischemic optic neuropathy, regardless of the association with previous administration of PDE-5 inhibitors;
  • the safety of Levitra® has not been investigated and, until the relevant data are obtained, its use is not recommended in patients with the following conditions: severe liver dysfunction (Child-Pugh class C); end-stage kidney disease requiring hemodialysis; arterial hypotension (systolic pressure at rest less than 90 mmHg.); a recent stroke or myocardial infarction (within the last 6 months); unstable angina; hereditary degenerative diseases of the retina, for example, retinitis pigmentosa.

With caution, the drug should be used in patients with anatomical deformity of the penis (curvature, cavernous fibrosis, Peyronie's disease), with aortic stenosis or idiopathic hypertrophic subaortic stenosis, with diseases predisposing to priapism (sickle cell anemia, multiple myeloma, leukemia). In patients with a tendency to bleeding and with an exacerbation of peptic ulcer disease, the drug should be prescribed only after assessing the benefit-risk ratio.

Contraindications to the use of Levitra

  1. Hypersensitivity to any of the components of the drug;
  2. simultaneous use with nitrates or drugs that are nitric oxide donors;
  3. simultaneous use with riociguate, a stimulant of soluble guanylate cyclase;
  4. concomitant use with moderately active or potent CYP3A4 inhibitors, such as erythromycin, ketoconazole (at a dose of more than 200 mg), itraconazole (at a dose of more than 200 mg), clarithromycin, indinavir and ritonavir;
  5. severe heart failure (III-IV functional class);
  6. in patients with a history of unilateral vision loss due to nonarteritic anterior ischemic optic neuropathy, regardless of the association with previous administration of PDE-5 inhibitors;
  7. the safety of Levitra® has not been investigated and, until the relevant data are obtained, its use is not recommended in patients with the following conditions: severe liver dysfunction (Child-Pugh class C); end-stage kidney disease requiring hemodialysis; arterial hypotension (systolic pressure at rest less than 90 mmHg.);
  8.  recent stroke or myocardial infarction (within the last 6 months); unstable angina; hereditary degenerative diseases of the retina, for example, retinitis pigmentosa.

With caution, the drug should be used in patients with anatomical deformity of the penis (curvature, cavernous fibrosis, Peyronie's disease), with aortic stenosis or idiopathic hypertrophic subaortic stenosis, with diseases predisposing to priapism (sickle cell anemia, multiple myeloma, leukemia).