Zidena, 100 mg

Udenafil is a selective reversible inhibitor of specific FDE-5 that promotes cGMP metabolism.
Udenafil has no direct relaxing effect on the isolated cavernous body, but with sexual stimulation it increases the relaxing effect of nitric oxide by inhibiting FDE-5, responsible for cGMP breakdown in the cavernous body.
A consequence of this is relaxation of arterial smooth muscles and blood flow to the tissues of the penis, which causes an erection. The drug has no effect in the absence of sexual stimulation.
Studies in vitro have shown that udenafil is a selective inhibitor of FDE-5 enzyme. FDE-5 is present in the smooth muscles of the cavernous body, in smooth muscles of vessels of internal organs, in skeletal muscles, platelets, kidneys, lungs and cerebellum. Udenafil is 10000 times more powerful inhibitor against FDE-5 than against FDE-1, FDE-2, FDE-3 and FDE-4, which are localized in the heart, brain, blood vessels, liver and other organs.
Also, Udenafil is 700 times more active against FDE-5 than against FDE-6, found in the retina and responsible for color vision. Udenafil does not inhibit FDE-11 that is why there are no cases of myalgia, lower back pain and testicular toxicity.
Udenafil improves erection and possibility of successful intercourse.
The action of the drug lasts for 24 hours. The effect appears as early as 30 minutes after taking the drug in the presence of sexual arousal.
Udenafil in healthy individuals does not cause significant changes in BP and BPD compared to placebo in the lying and standing position (the average maximum decrease is 1.6/0.8 and 0.2/4.6 mm Hg, respectively).
Udenafil does not cause changes in color recognition (blue/green), due to its low affinity for FDE-6. Udenafil does not affect visual acuity, electroretinogram, intraocular pressure and pupil size.
When studying udenafil in men no clinically significant effect of the drug on the number and concentration of sperm, motility and morphology of spermatozoa was found.

Intake
After oral administration, udenafil is rapidly absorbed. Tmax in plasma is 30-90 minutes (on average 60 minutes).
T1/2 is 12 hours, high plasma protein binding of udenafil (93,9%) prolongs its effectiveness period to 24 hours after a single dose.
Intake of high fat food has no effect on absorption of udenafil.
Alcohol intake of 112 mL (in terms of 40% ethanol) in combination with oral administration of udenafil at a dose of 200 mg does not affect the pharmacokinetic profile of udenafil.

Metabolism
Udenafil is primarily metabolized with participation of cytochrome P450 isoenzyme CYP3A4.

Elimination
In healthy people the total clearance of udenafil is 755 ml/min. After oral administration udenafil is excreted as metabolites in the feces.

Udenafil does not accumulate in the body. No significant changes in its pharmacokinetics were detected when administered daily in healthy volunteers in doses of 100 and 200 mg/day for 10 days.

Indications

The treatment of erectile dysfunction characterized by the inability to achieve or maintain an erection of the penis sufficient for satisfactory intercourse.

Active ingredient

Udenafil

Composition

1 tablet contains:
active ingredient:
udenafil – 100 mg
excipients:
lactose, corn starch, colloidal silica, L-hydroxypropylcellulose hydroxypropylcellulose-LF, talc, magnesium stearate;
shell:
hydroxypropyl methylcellulose, talc, iron oxide red, iron oxide yellow, titanium dioxide.

How to take, the dosage

The drug is taken orally, regardless of meals. The recommended dose of the drug is 100 mg, taken 30 minutes before the intended sexual activity.

The dose can be increased up to 200 mg, taking into account individual effectiveness and tolerability of the drug.

The maximum recommended frequency of use is once daily.

Interaction

Cytochrome P450 CYP3A4 isoenzyme inhibitors (ketoconazole, itraconazole, ritonavir, indinavir, cimetidine, erythromycin, grapefruit juice) may increase the effect of udenafil.

Ketoconazole (at a dose of 400 mg) increases the bioavailability and C_max of udenafil (at a dose of 100 mg) by nearly twice (212%) and 0.8 times (85%), respectively. Ritonavir and indinavir significantly enhance the effects of udenafil. Dexamethasone, rifampin and anticonvulsants (carbamazepine, phenytoin and phenobarbital) may accelerate the metabolism of udenafil, so co-administration with the above drugs weakens the effect of udenafil.

The co-administration of udenafil (30 mg/kg, orally) and nitroglycerin (2.5 mg/kg once intravenously) showed no effect on the pharmacokinetics of udenafil in experimental studies, but the simultaneous use of nitroglycerin and udenafil is not recommended because of the possible decrease in blood pressure.

Udenafil and drugs from the group of alpha-blockers are vasodilators, so when taken together they should be prescribed in minimal doses.

Special Instructions

Sexual activity has potential risks for patients with cardiovascular disease, so erectile dysfunction treatment, including the use of udenafil, should not be performed in men with heart disease in which sexual activity is not recommended.

Patients with left ventricular outflow tract obstruction (aortic stenosis) may be more sensitive to the action of vasodilators, including FDE inhibitors. Despite the absence of cases of prolonged erection (more than 4 hours) and priapism (painful erection lasting more than 6 hours) in clinical studies, these phenomena are characteristic of this class of drugs.

If an erection lasts more than 4 hours (regardless of pain), patients should seek medical attention immediately. If not treated promptly, priapism can lead to permanent damage to erectile tissue and erectile function.

Due to the lack of clinical data on the use of udenafil in patients over 71 years of age, this category of patients is not recommended to take this drug. It is not recommended to use udenafil in combination with other treatments of erectile dysfunction.

Contraindications

• High sensitivity to any of the ingredients of the drug;
• concurrent use of nitrates and other nitric oxide “donors.

Cautions

Uddenafil should be used with caution in patients with uncontrolled arterial hypertension (blood pressure >170/100 mm Hg.

Patients with uncontrolled arterial hypertension (blood pressure >170/100 mm Hg), hypotension (blood pressure

With caution, use udenafil in patients with a predisposition to priapism, as well as in patients with anatomical deformity of the penis, in the presence of a penile implant.

Side effects

Side effects observed during clinical trials of udenafil, depending on their frequency of occurrence: very often – ≥10% of cases; often – 1-10%; sometimes – 0.1-1%.

Cardiovascular system: very often – flushes to the face.

CNS disorders: sometimes – dizziness, neck muscle stiffness, paresthesia.

Visual organs: often – red eyes; sometimes – blurred vision, pain in the eyes, increased lacrimation.

Skin disorders: sometimes – eyelid swelling, facial edema, urticaria.

The digestive system: often – dyspepsia, abdominal discomfort; sometimes – nausea, toothache, constipation, gastritis.

Respiratory system: often – nasal congestion; sometimes – shortness of breath, dry nose.

Motor system disorders: sometimes – periarthritis.

The body in general: often – headache, discomfort in the chest, a feeling of fever; sometimes – chest pain, abdominal pain, fatigue, thirst.

Other adverse events have also been described during postmarketing observations with udenafil use: palpitations, nosebleeds, tinnitus, diarrhea, allergic reactions (skin rash, erythema), prolonged erections, feeling of general discomfort, feeling of cold or heat, postural dizziness, cough.

Overdose

When taking the drug at a single dose of 400 mg, adverse events were comparable to those observed when taking udenafil at lower doses, but were more frequent.
Treatment: symptomatic. Dialysis does not accelerate excretion of udenafil.

Pregnancy use

Zidena is not indicated for use in women.