Zydena

Zidena is a drug that improves erectile function.

Indications Zydena

It is indicated for the elimination of erectile dysfunction, which manifests itself as the inability to achieve an erection or to maintain it in a form sufficient for satisfactory sexual intercourse.

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Release form

Tablets of 100 mg. One blister contains 1, 2 or 4 tablets. 1 pack contains 1 such blister plate (in the amount of 1, 2 or 4 tablets) or 2 blister plates (in the amount of 1 or 2 tablets).

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Pharmacodynamics

The active ingredient udenafil is a selective inhibitor of the specific element PDE-5 (reversible action), which helps the process of cGMP metabolism.

Udenafil does not have a direct relaxant effect on the isolated corpus cavernosum, although under the influence of sexual stimulation it enhances the relaxant effect exerted by nitric oxide (by inhibiting PDE-5, which is responsible for the destruction of cGMP within the corpus cavernosum).

As a result, the smooth muscles of the arteries relax and blood flows to the tissues inside the penis, stimulating an erection. If there is no sexual stimulation, the drug will not have the desired effect.

In vitro testing has shown that udenafil acts as a selective inhibitor of the PDE-5 enzyme. This element is located inside the smooth muscles of the cavernous body, and along with this, the vessels of the organs, and in addition to this, in the skeletal muscles, kidneys with platelets, and also the cerebellum with the lungs. Udenafil slows down the PDE-5 element 10 thousand times more powerfully than the PDE-1 and PDE-2 enzymes, as well as PDE-3 with PDE-4, located inside the brain with the heart and liver, and in addition to this, blood vessels and other organs.

At the same time, the active ingredient is 700 times more powerful in its effect on PDE-5 than on the PDE-6 element (it is located in the retina, responsible for color perception). Udenafil does not slow down the activity of PDE-11, as a result of which it does not cause muscle and lumbar pain, as well as signs of testicular toxicity.

Thanks to the active substance, erection improves, which contributes to successful sexual intercourse.

The effect of the drug lasts up to 24 hours. It begins to manifest itself half an hour after taking it (provided that the man is sexually aroused).

In healthy men, the active component does not cause a reliable change in the values of systolic and diastolic blood pressure relative to placebo in lying and standing positions (the maximum reduced level on average is 1.6/0.8 and 0.2/4.6 mm Hg, respectively).

At the same time, udenafil does not change color perception (green/blue), since it has a weak affinity for the PDE-6 element. The substance does not affect intraocular pressure, visual acuity, and along with this, the size of the pupils and ERG.

In the course of testing, udenafil did not reveal any clinically significant effect on the concentration index, and therefore the quantity of sperm released, and also on the morphology and motility of spermatozoa.

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Pharmacokinetics

The drug is rapidly absorbed after oral administration. The peak plasma level occurs after 0.5-1.5 hours (on average 1 hour).

The half-life is 12 hours, and the high rate of synthesis of the substance with plasma protein (93.9%) extends the period of its action to 24 hours when taken as a single dose.

Eating food containing a large amount of fat does not affect the absorption rate of udenafil. The pharmacokinetic properties of the drug are also not affected by the simultaneous oral administration of the drug in the amount of 200 mg and alcohol in a dosage of 112 ml (recalculated to 40% ethyl alcohol).

Metabolism is carried out to the greatest extent with the participation of the CYP3A4 isoenzyme of hemoprotein P450.

The overall clearance rate of the component in a healthy person is 755 ml/minute. After oral administration, it is excreted in the form of decay products along with feces.

The active component does not accumulate in the body. When volunteers took the drug daily in doses of 100 and 200 mg for 10 days, no noticeable changes in the pharmacokinetics of the drug were found.

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Dosing and administration

The medicine is taken orally, regardless of food. The recommended dosage is 100 mg. The tablet should be taken half an hour before the expected sexual intercourse.

Taking into account the individual reaction to the drug, as well as its effectiveness, the dosage may be increased to 200 mg.

The drug can be taken no more than once a day.

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Contraindications

Among the contraindications of the drug:

• intolerance to any of the components of the drug;
• combined use with nitrates and other nitrogen oxide producers;
• children under 18 years of age.

Caution is required when prescribing in the following cases:

• men with uncontrolled increase in blood pressure (more than 170/100 mm Hg), as well as decrease in blood pressure (less than 90/50 mm Hg);
• people with a hereditary form of degenerative retinal pathology (including retinitis pigmentosa and proliferative retinitis);
• persons who have suffered a myocardial infarction, stroke or coronary artery bypass grafting in the last six months;
• if the patient has severe renal or liver failure;
• in case of congenital QT syndrome or prolongation of this indicator due to medication use;
• predisposition to the development of priapism;
• men with anatomically deformed penis;
• patients with a penile implant;
• people with cardiovascular pathologies – unstable angina or angina that occurs during sexual intercourse; chronic heart failure (II–IV functional class according to the NYHA classification) that has developed in the patient over the past six months; and also with uncontrolled heart rhythm disorders: in such cases, it is necessary to take into account the possibility of complications;
• combined use with α-blockers, CCBs or other antihypertensive drugs, as this can cause an additional decrease in diastolic blood pressure, as well as systolic blood pressure by 7-8 mm Hg.

Side effects Zydena

As a result of using the drug, the following side effects may develop:

• cardiovascular system organs: there is often a rush of blood to the skin of the face;
• CNS organs: in some cases, dizziness, paresthesia, or cervical radiculitis may develop;
• visual organs: often there is redness of the eyes, in rarer cases there is pain, blurred vision or increased lacrimation;
• skin: in some cases, urticaria develops, swelling occurs on the face or eyelids;
• digestive system organs: mainly discomfort in the abdomen or dyspeptic symptoms develop; less often, toothaches or nausea occur, gastritis or constipation develops;
• respiratory system: nasal congestion usually occurs, and occasionally dyspnea or dryness of the nasal mucosa develops;
• musculoskeletal system: periarthritis develops occasionally;
• General: often there is a feeling of discomfort in the chest or headache, and also fever; occasionally there is abdominal pain, chest pain, a feeling of thirst or fatigue.

During post-marketing testing of the drug, other adverse effects were also described: increased heart rate, nosebleeds, diarrhea, tinnitus, allergic reactions (erythema and skin rashes), prolonged erection, a feeling of noticeable general discomfort, and in addition to cold or heat, as well as coughing and positional dizziness.

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Overdose

In the case of using the drug in the amount of 400 mg, the adverse reaction was comparable to the symptoms observed when using the drug in smaller doses, but they were more frequent.

To eliminate an overdose, therapy aimed at relieving symptoms should be used. The dialysis procedure does not accelerate the process of excretion of the active component of the drug.

Interactions with other drugs

Inhibitors of the hemoprotein P450 isoenzyme CYP3A4 (such as indinavir with ritonavir, erythromycin with cimetidine, as well as itraconazole with ketoconazole and grapefruit juice) can increase the properties of udenafil.

Ketoconazole (at a dosage of 400 mg) increases the plasma peak and bioavailability of udenafil (at a dosage of 100 mg) by 0.8 times (or 85%) and almost twice (or 212%), respectively.

Ritonavir with indinavir significantly enhance the properties of udenafil.

Rifampin, dexamethasone, and anticonvulsants (such as phenytoin with carbamazepine and phenobarbital) can accelerate the metabolism of udenafil, as a result of which, when these drugs are used in combination, the properties of the latter are weakened.

When udenafil was used in combination (orally at a dose of 30 mg/kg) with nitroglycerin (single intravenous administration of 2.5 mg/kg) under experimental testing conditions, no effect on the pharmacokinetic properties of udenafil was observed, but combining them is still not recommended, as this may lower blood pressure.

Udenafil, as well as drugs included in the category of α-blockers, are vasodilators, so in case of simultaneous use they should be prescribed in minimal dosages.

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Storage conditions

The medicine must be kept in a place protected from sunlight and moisture, and inaccessible to children. Temperature – no more than 30°C.

Shelf life

Zidena can be used for 3 years from the date of manufacture of the medicine.

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