Dosage form

Tablets, film-coated yellow, almond-shaped, with the inscription "20" on one side

Composition

tadalafil 20 mg

Excipients: lactose monohydrate, hyprolose (hydroxypropyl cellulose), croscarmellose sodium , microcrystalline cellulose, magnesium stearate, sodium lauryl sulfate.

The film composition of the shell: Opadry II yellow - lactose monohydrate, hypromellose, titanium dioxide, triacetin, dye iron oxide yellow

Pharmacological action

Drug for treatment of erectile dysfunction. Is a reversible selective inhibitor of specific phosphodiesterase type 5 (PDE5) cGMP. When sexual stimulation causes local release of nitric oxide, inhibition of PDE5 tadalafil leads to increased levels of cGMP in the cavernous body of penis. The result is relaxation of smooth muscles of arteries and blood flow to the tissues of the penis that causes erections. Tadalafil has no effect without sexual stimulation.

Studies in vitro have demonstrated that tadalafil is a selective inhibitor of PDE5. PDE5 - an enzyme found in smooth muscles cavernous bodies in vascular smooth muscle of internal organs, skeletal muscle, platelets, kidney, lung, cerebellum.

The action of tadalafil on PDE5 is more active than other phosphodiesterase. Tadalafil 10 000 times more active against PDE5 than for ФДЭ1, ФДЭ2, ФДЭ4, ФДЭ7, which are localized in heart, brain, blood vessels, liver, leukocytes, skeletal muscle and in other organs. Tadalafil 10 000 times more actively blocks PDE5 than ФДЭ3 the enzyme that is found in the heart and blood vessels. This selectivity concerning PDE5 compared to ФДЭ3 is important because ФДЭ3 is an enzyme participating in the reduction of cardiac muscle. In addition, tadalafil about 700 times more active against PDE5 than for ФДЭ6 found in the retina and is responsible for photoperiodic.

Tadalafil is also showing the action in 9000 times more potent against PDE5 compared to its effect on ФДЭ8, 9 and 10 and 14 times more potent against PDE5 compared to ФДЭ11. Tissue distribution and physiological effects of inhibiting ФДЭ8-ФДЭ11 so far not been elucidated.

Cialis improves erection and the possibility of successful sexual intercourse.

The drug acts within 36 hours the Effect is already apparent 16 minutes after ingestion in the presence of sexual arousal.

Tadalafil in healthy individuals does not cause significant changes in systolic and diastolic BP, compared with placebo, in the supine position (mean maximum decrease in blood pressure is 1.6/0.8 mm Hg.St. respectively) and standing (mean maximum decrease AD is 0.2/4.6 mm Hg.St. respectively). Tadalafil does not cause significant changes in heart rate.

Tadalafil does not cause changes in color recognition (blue/green), due to its low affinity to ФДЭ6. In addition, no marked effect of tadalafil on visual acuity, electroretinogram, intraocular pressure and pupil size.

With the aim of assessing the impact tadalafil with a daily intake on spermatogenesis have been several studies. None of the studies was not observed undesirable effects on the morphology of spermatozoa and their mobility. In one study, it was revealed decrease in the mean of sperm concentration compared to placebo. The decline in sperm count was associated with higher frequency of ejaculation. In addition, tadalafil did not cause undesirable changes of testosterone, LH and FSH in blood plasma, compared to placebo.

Pharmacokinetics

Suction

After oral tadalafil is rapidly absorbed. Cmax is reached after an average of 2 h. the Rate and extent of absorption do not depend on food intake. The time of dosing (morning or evening) has no clinically significant effect on the rate and extent of absorption.

The pharmacokinetics of tadalafil at healthy persons is linear in regard to time and dose. In the dose range of 2.5 to 20 mg AUC increases proportionally with dose. Css in plasma are attained within 5 days while taking the drug 1 time/

The pharmacokinetics of tadalafil in patients with dysfunction of the erection similar to the pharmacokinetics of the drug in individuals without the dysfunction of erection.

Distribution

Average Vd is about 63 liters, indicating that tadalafil is distributed in body tissues. At therapeutic concentrations 94% of tadalafil bound to plasma proteins. In healthy persons less than 0.0005% of administered dose detected in semen.

Metabolism

Metabolized mainly involving isoenzyme CYP3A4. The major circulating metabolite is methylethanolamine. It is 13,000 times less active against PDE5 than tadalafil. Therefore, this metabolite is unlikely to be clinically significant.

Excretion

In healthy individuals the average clearance of tadalafil ingestion of 2.5 l/h, and the average T1/2 - 17.5 hours Tadalafil is excreted predominantly as inactive metabolites, mainly with feces (about 61%) and to a lesser extent from the urine (approximately 36%).

Pharmacokinetics in special clinical cases

In healthy elderly (65 and over) is determined by a lower clearance of tadalafil, resulting in the increase in AUC by 25% compared with healthy individuals aged 19 to 45 years. This difference is not clinically significant and does not require dose adjustment.

In patients with renal insufficiency, including patients on hemodialysis, the AUC more than in healthy. protein Binding does not change when the impairment of renal function.

The pharmacokinetics of tadalafil in patients with mild or moderate hepatic insufficiency is comparable to that in healthy subjects. In patients with severe hepatic insufficiency (class C according to child-Pugh) data are not available.

In patients with diabetes mellitus on the background of the use of tadalafil AUC was lower by about 19% than in healthy individuals. This distinction is not does not require change of dose.

Side effects

Most frequently: headache (11%), dyspepsia (7%).

Side effects are usually mild or moderate in severity, transient and diminish with continued dosing.

Possible: back pain, myalgia, dizziness, nasal congestion, tides blood to a person.

Rare: swelling of the eyelids, eye pain, conjunctival hyperemia.

Very rare: hypersensitivity reactions (including rash, urticaria and facial edema, Stevens-Johnson syndrome and exfoliative dermatitis); hypotension (in patients who are already taking antihypertensive agents), hypertension and syncope; abdominal pain and gastroesophageal reflux; hyperhidrosis (excessive sweating); priapism and delayed erection; blurry vision, partitially anterior ischemic neuropathy of the optic nerve, Central retinal vein occlusion, impaired visual field, migraine, epistaxis.

In patients with cardiovascular risk factors: myocardial infarction, cardiogenic sudden death, stroke, chest pain, palpitations, tachycardia. However, it is impossible to pinpoint whether these phenomena directly with these risk factors, with tadalafil, with sexual arousal, or a combination of these or other factors.

Special conditions

With caution should appoint drug patients with severe hepatic insufficiency (class C according to child-Pugh), because data-controlled clinical studies on safety and efficacy of the drug Cialis® in this category of patients lacking.

Care is needed when prescribing the drug Cialis® patients taking alpha1-blockers, for example doxazosin, since simultaneous application in some cases can cause symptomatic hypotension. In studying the clinical pharmacology in 18 healthy volunteers who took cialis in the single dose was not observed symptomatic arterial hypotension at the simultaneous introduction of alpha1-adrenoblocker tamsulosin.

Sexual activity has a potential risk for patients with cardiovascular diseases. Therefore, treatment of erectile dysfunction, including with the use of the drug Cialis®, should not be performed in men with such diseases of heart at which sexual activity is not recommended.

Be aware of the potential risk of complications during sexual activity in patients with diseases of the cardiovascular system: myocardial infarction within the last 90 days; unstable angina or angina occurring during sexual intercourse; chronic heart failure (II functional class and higher classification of NYHA), which developed in the last 6 months; uncontrolled cardiac arrhythmia; arterial hypotension (BP less than 90/50 mm Hg.St.) or uncontrolled hypertension; stroke, myocardial in the last 6 months.

Caution should be used Cialis® in patients with renal failure, severe (CC less than 30 ml/min) renal insufficiency medium severity (QC from 31 to 50 ml/min), in patients with predisposition to priapism (e.g., sickle cell anemia, multiple myeloma or leukemia) or in patients with anatomical deformation of the penis (e.g. angulation, cavernous fibrosis or Peyronie's disease).

There are reports of occurrence of priapism with the use of PDE5 inhibitors, including tadalfil. The patient should be informed of the need for immediate treatment to the doctor in case of erection, continued for 4 h or more. Delays in treatment of priapism leads to tissue damage of the penis, as a result, may occur long-term loss of potency.

The safety and effectiveness of combination drug Cialis® with other treatments for erectile dysfunction have not been studied. Therefore, the use of such combinations is not recommended.