Levitra

Levitra is a drug that helps improve erectile function.

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Indications Levitra

It is used to eliminate impotence (the drug is a potency regulator) – when it is present, a man is unable to achieve the level of erection required to perform a successful sexual act, and also to maintain it.

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Release form

The release is carried out in tablets of 10 or 20 mg, in blister strips, 1 or 4 pieces inside them. There is also a dosage of the drug, which is 5 mg - such tablets are produced 4 pieces inside a blister, 5 such strips inside a box.

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Pharmacodynamics

The most well-known PDE is the specific form of PDE-5, which participates in the processes of cleavage by hydrolyzing GMP (this function is one of the options for regulating cGMP levels during penile erection).

Vardenafil is a PDE5 blocker and also potentiates the local action of internal NO, which is secreted through the nerve receptors of the cavernous bodies under the influence of a sexual stimulus. The NO element is required to activate the enzyme guanylate cyclase, which increases the level of cGMP and helps to relax the smooth muscles inside the cavernous bodies. As a result, blood flow to the penis increases. In this way, Levitra potentiates the body's natural response to a sexual stimulus.

It has been found that the average values required to slow down PDE-5 are 0.7 nanoM. Therefore, vardenafil is a powerful, highly selective inhibitor. The use of 20 mg of vardenafil already after 15 minutes causes an erection in some men, which is sufficient for penetration. To get a full reaction, you should wait 25 minutes.

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Pharmacokinetics

Absorption.

Absorption after oral administration is very fast, when taken on an empty stomach, the peak value of the drug can be reached after 15 minutes, but often (in 90% of cases) it still takes about 1 hour. When taken with fatty foods, the absorption rate of the drug decreases by an average of 20%.

Absolute bioavailability is about 15%. The steady-state distribution volume is 208 l. The synthesis rates of the main element (M1) with protein in blood plasma are a maximum of 95% (reversible reaction). After 1.5 hours, up to 0.00012% of the drug portion can be found in the sperm of a healthy man.

Metabolic processes and excretion.

Metabolism is mainly carried out by liver enzymes and hemoprotein systems. The average half-life is about 4-5 hours, and for the main metabolic product (it is formed by deethylation of the piperazine part inside the molecule) it is about 4 hours.

Metabolic products are excreted mainly through the gastrointestinal tract (about 91-95%), and the remainder through the kidneys.

Changes in AUC and other drug values in different categories of patients.

AUC values in elderly subjects are often increased by 52%.

In individuals with severe renal impairment, the AUC increases by approximately 21% and the peak drug level decreases by 23%.

Due to disorders of liver function, clearance rates decrease in accordance with the severity of the functional disorder.

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Dosing and administration

The medicine is taken orally, without regard to food intake, approximately 25-60 minutes before sexual intercourse.

Standard mode of use.

The recommended initial dose is 10 mg. The medicine should not be taken more than once every 24 hours. Taking into account the tolerability of the course and the effectiveness of the therapeutic effect, the daily dosage can be increased to 20 mg or decreased to 5 mg.

Use of the therapeutic agent in people with liver dysfunction.

The recommended initial dose of the medication is 5 mg. During treatment, it can be increased to 10 mg.

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Contraindications

Main contraindications:

• the presence of hypersensitivity to any of the components of the drug;
• persons using drugs containing nitrates or NO donors, as well as substances that inhibit the activity of CYP3A4 (including indinavir, itraconazole and ritonavir with clarithromycin, as well as erythromycin with ketoconazole);
• treatment with other medications for impotence;
• use in men who are prohibited from sexual activity (for example, in the presence of such background diseases in the cardiovascular system as acute heart failure or unstable angina);
• severe liver dysfunction;
• performing hemodialysis at the initial stage of renal pathology;
• decreased blood pressure (at rest below 90 mm Hg);
• recent myocardial infarction or stroke (six months or less before);
• degenerative forms of pathologies in the retinal area that are hereditary (such as retinitis pigmentosa);
• newborn babies and children, as well as women.

Caution is required when prescribing in such cases (the benefit/risk ratio must be assessed):

• anatomical deformation of the penis (this includes various curvatures, as well as Peyronie's disease and cavernous fibrosis);
• the presence of a predisposition to the development of priapism - for example, multiple myeloma, sickle cell anemia, a tendency to bleeding, and leukemia;
• ulcer in the acute stage.

Side effects Levitra

The use of the drug may cause the following side effects:

• diseases of infectious nature: development of conjunctivitis;
• problems with the central nervous system and psyche: the appearance of headaches and sleep disorders;
• visual impairment: deterioration of visual acuity and color perception, feeling of pain or discomfort in the eye area, increased intraocular pressure, photosensitivity and hyperemia in the conjunctiva;
• auditory disorder: sudden development of deafness, as well as tinnitus and vertigo;
• immune lesions: Quincke's edema or swelling of an allergic nature, as well as allergy symptoms;
• disorders in the functioning of the cardiovascular system: the appearance of angina pectoris, ventricular tachyarrhythmia, tachycardia, palpitations, the development of vasodilation or myocardial infarction, as well as a decrease in blood pressure values;
• gastrointestinal dysfunction: nausea, gastritis, dry mouth, dyspeptic symptoms, GERD, vomiting, abdominal pain and diarrhea;
• lesions in the sternum and mediastinum, as well as respiratory activity: dyspnea, congestion in the nasal area with paranasal sinuses;
• problems affecting the liver and biliary tract: increased transaminase activity;
• lesions of the subcutaneous layer and surface of the skin: rashes or erythema;
• dysfunction of connective tissues, muscles and skeleton: pain in the back, increased muscle tone, increased CPK values, and also myalgia;
• disorders in the mammary glands and genitals: development of priapism and increased erection;
• systemic: pain in the chest area and poor health.

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Overdose

When using vardenafil in a dose of 40 mg twice a day, the patient may develop severe pain in the lower back. However, no symptoms of toxic effects on the central nervous system and muscles are noted.

To remove the overdose, it is necessary to carry out the usual supportive procedures. The effectiveness of hemodialysis in this case is very low.

Interactions with other drugs

When combined with drugs that inhibit CYP activity, the clearance rate of vardenafil may decrease.

Combination with erythromycin in a daily dose of 1.5 g leads to a fourfold increase in the AUC level, as well as a threefold increase in peak drug levels (5 mg).

Combined use with ketoconazole in a 0.2 g dose causes a 10-fold increase in AUC values, and in addition a 4-fold increase in peak drug values (5 mg), so their doses need to be adjusted.

The combination of the drug with drugs that inhibit HIV proteases of the active component (indinavir in a daily dose of 2.4 g) causes a 16-fold increase in AUC values and a 7-fold increase in the peak level of the active ingredient of Levitra.

Concomitant use with ritonavir (daily dose size 1.2 g) increases peak drug levels by 13 times at a dose of 5 mg, and also causes a 49-fold increase in the total daily AUC value. In addition, the half-life of vardenafil is significantly prolonged (by approximately 26 hours).

When combined with NO donors and nitrates, their effect is enhanced, but if a 24-hour interval is observed between uses, such interaction does not develop.

The use of excessively large doses of vardenafil in combination with sodium nitroprusside leads to a slight increase in the antiplatelet effect.

It is necessary to observe time intervals between the use of the drug and α-blockers, and also to use them only when the blood pressure level is stable. For example, for use together with terazosin, it is necessary to maintain a 6-hour interval.

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Storage conditions

Levitra should be kept in a place closed to small children and moisture penetration. Temperature level – maximum +30°C.

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Shelf life

Levitra can be used for 3 years from the date of release of the therapeutic agent.

Analogues

The analogs of the drug are Viagra, Adamax, and Dzhenagra.

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Reviews

Levitra is considered an effective and affordable medicine that helps improve erection. Patients leave positive reviews about the drug, noting that it can be consumed with alcoholic beverages, as well as in the presence of certain diseases affecting the cardiovascular system.