Description Levitra:
Commercial (proprietary) name: Levitra
International (nonproprietary) name: Vardenafil

Pharmacological action: By blocking the enzyme fosfodiesterazu type 5 (PDE-5), under the influence of which is split cGMP, Levitra, thereby providing enhancement of endogenous NO in the cavernous bodies, resulting in the ability of the drug enhances the natural response to sexual stimulation. The clinical effect is realized before reaching Smax. Getting action after oral administration of 20 mg and 10 mg starts in 10 minutes, allowing an erection sufficient for penetration and successful completion of intercourse at 34 and 40% of patients with mild to moderate mild erectile dysfunction, respectively. After 25 min, respectively, the effect occurs in 53% and 50% of patients, which coincides with the beginning of the emergence of drug in the blood and the rapid growth of its concentration.
Duration – 8-12 hours

Pharmacokinetics: Levitra is rapidly absorbed after oral administration. TCmax – 30-120 min. Absolute bioavailability – 15%. When receiving a diet containing no more than 30% fat, pharmacokinetic parameters (Cmax, TCmax, AUC) are not changed. Simultaneous treatment with a diet containing high fat (57%), reduces the rate of absorption (TCmax increased to 60 min), Cmax decreased by 20% without a significant change in AUC. Vardenafil and its major metabolite (M1) is well bound to plasma proteins (up to 95%), and this property is reversible and not dependent on the total concentration of the drug. 90 min after administration of oral vardenafil in semen found no more than 0.00012% of the dose. Is metabolized predominantly hepatic oxidases with cytochrome P450 isozymes CYP3A4, and CYP3A5 and CYP2C9. T1 / 2 – 4-5 h, the main metabolite M1 – 4 h. The total clearance – 56 l / h. We derive mainly from the stool in the form of metabolites (91-95%), to a lesser extent the kidneys (2-6%). Older men (over 65 years) compared with young men (18-45 years) a significant reduction of hepatic clearance is not marked. On average, Cmax and AUC in the elderly increased by 34 and 52% respectively. Patients with small (QA over 55-80 ml / min) renal insufficiency changes of pharmacokinetic parameters were observed, with moderate (QA over 30-50 ml / min) and severe (less than 30 ml / min) renal insufficiency AUC increased by 20 — 30%. Patients on hemodialysis, pharmacokinetics of vardenafil has not been studied. In patients with hepatic insufficiency (Child class of scale-Pyuga) Cmax and AUC after oral administration of 10 mg increased to 22 and 17% respectively (1.2 times) with moderate hepatic impairment (class B on the scale of Child-Pyuga) Cmax and AUC increased by 130 and 160% respectively (2.6 times). Pharmacokinetics was not studied in patients with severe hepatic insufficiency (class C on the scale of Child-Pyuga).

Indications: Levitra is designed to enhance potency in men suffering from erection disorders (erectile dysfunction), including the extreme form of erectile dysfunction – impotence. These disturbances lacked sufficient for sexual intercourse erection or weak erection.

Contraindications: Hypersensitivity, simultaneous reception of organic nitrates or other LAN emitting NO, alpha-blockers. Severe hepatic insufficiency, renal disease in the terminal stage, requiring dialysis, hypotension (systolic blood pressure at rest less than 90 mm Hg. St), recent myocardial infarction or stroke (within the past 6 months), unstable angina, the hereditary degenerative disease of the retina ( including retinitis pigmentosa). Age 16 years.

Dosage regimen: inside, regardless of the meal. Initial recommended dose – 10 mg for 25-60 minutes before sexual intercourse. Can be taken at any time during the period from 4-5 h up to 25 minutes before sexual activity. The maximum recommended frequency of admission – 1 times per day. To be effective requires a sufficient level of sexual stimulation. Depending on the efficacy and tolerability the dose may be increased to 20 mg or decreased to 5 mg per day. The maximum daily dose – 20 mg. Corrections dosing regime in elderly patients is not required. Patients with severe hepatic insufficiency insignificant correction dosing regime is not required. In patients with moderate hepatic impairment initial dose – 5 mg per day. In the future, depending on the efficacy and tolerability of treatment dose can be increased to 10 mg and then to 20 mg. Patients with mild and moderate renal insufficiency correction dosing regime is not required.

Side effects:
More than 10%: headache, hot flushes blood to the skin.
Frequent (1-10%): dyspepsia (including nausea), dizziness, nasal congestion.
Infrequent (0.1-1%): increase of blood pressure, photosensitivity reaction.
Rare (0.01-0.1%): reduction of blood pressure, increased muscle tone, priapism.
Cautions: Due to the fact that sexual activity is associated with some degree of deterioration in the flow of cardiovascular disease, before making an appointment at the treatment of erectile dysfunction is necessary to assess the state of the cardiovascular system of the patient.

Interaction: Inhibitors of cytochrome P450 (cimetidine, ketoconazole, itraconazole, indinavir, ritonavir) may decrease the clearance of vardenafil (if joint application with these drugs should not exceed the dose of vardenafil 5 mg / day). In a joint application with the CYP3A4 inhibitor erythromycin did not exceed the recommended dose of vardenafil 10 mg per day. Concomitant use of alpha-blockers may cause a decrease in blood pressure, so Levitra should be taken no earlier than 6 h after administration of alpha-blockers. There have not been significant pharmacokinetic interactions when co-application of Levitra with glyburide, nifedipine, warfarin and digoxin. In a joint application with warfarin was not observed changes in prothrombin time and clotting factors. In a joint application with the ASC, antacids, ACE inhibitors, beta-blockers, diuretics, hypoglycemic LAN (sulfonylureas and metformin), ranitidine pharmacokinetics of vardenafil has not changed. Since PDE inhibitors affect the system NO / cGMP, PDE5 inhibitors may increase the hypotensive effects of nitrates. Monotherapy vardenafilom not inhibit platelet aggregation induced by various platelet agonists. In applying Levitra in concentrations exceeding therapeutic, there was a slight dose-dependent increase antiagregatsionnogo effect of sodium nitroprusside, singling NO. With caution the anatomic deformity of the penis (curved, cavernous fibrosis or Peyronie’s disease), diseases that predispose to the development of priapism (sickle cell anemia, multiple myeloma, or leukemia), the tendency to bleeding, peptic ulcer and 12 duodenal ulcer in the acute stage.

Overdose: Symptoms: pain in the back with no signs of toxic effects on muscle and nervous system.
Treatment: symptomatic. Not output through hemodialysis.