Tadalafil 20mg

With extreme caution and only if absolutely necessary, it is possible to use tadalafil in patients with severe renal insufficiency (CC < 30 ml / min) and severe hepatic insufficiency.

Against the background of treatment with tadalafil, patients with moderate renal insufficiency (CC from 31 to 50 ml/min) had back pain more often compared with patients with mild renal insufficiency (CC from 51 to 80 ml/min) or healthy volunteers. In patients with CC <50 ml / min, tadalafil should be used with caution. Therefore, treatment of erectile dysfunction, including with the use of tadalafil, should not be carried out in men with such heart diseases in which sexual activity is not recommended.

The potential risk of complications during sexual activity in patients with diseases of the cardiovascular system should be taken into account:

  1. myocardial infarction during the last 90 days; unstable angina or angina pectoris occurring during sexual intercourse;
  2. chronic heart failure (II functional class and higher according to the NYHA classification) that has developed over the past 6 months;
  3. uncontrolled disorders heart rate; arterial hypotension (blood pressure less than 90/50 mmHg) or uncontrolled hypertension;
  4. stroke suffered during the last 6 months.

Tadalafil should be used with caution in patients with a predisposition to priapism (for example, with sickle cell anemia, multiple myeloma or leukemia) or in patients with anatomical deformity of the penis (for example, with angulation, cavernous fibrosis or Peyronie's disease).

The patient should be informed of the need to immediately consult a doctor in case of an erection lasting 4 hours or more. Untimely treatment of priapism leads to damage to the tissues of the penis, as a result of which a long-term loss of potency may occur. Against the background of the use of tadalafil, no cases of priapism have been reported. It is not recommended to use tadalafil in combination with other types of erectile dysfunction treatment.

Pharmacological action

A remedy for the treatment of erectile dysfunction, it is a reversible selective inhibitor of specific PDE5 cGMP. When sexual arousal causes local release of nitric oxide, inhibition of PDE5 by tadalafil leads to an increase in cGMP levels in the cavernous body of the penis. The consequence of this is relaxation of the smooth muscles of the arteries and blood flow to the tissues of the penis, which causes an erection. Tadalafil is ineffective in the absence of sexual stimulation.

In vitro studies have shown that tadalafil is a selective PDE5 inhibitor. PDE5 is an enzyme found in the smooth muscles of the cavernous body, in the smooth muscles of the vessels of internal organs, in skeletal muscles, platelets, kidneys, lungs, cerebellum.

The effect of tadalafil on PDE5 is more active than on other phosphodiesterases. Tadalafil is 10,000 times more active against PDE5 than against PDE1, PDE2, PDE4, which are localized in the heart, brain, blood vessels, liver and other organs. Tadalafil is 10,000 times more active in blocking PDE5 than PDE3, an enzyme found in the heart and blood vessels. This selectivity for PDE5, compared to PDE3, is important because PDE3 is an enzyme involved in cardiac muscle contraction. In addition, tadalafil is approximately 700 times more active against PDE5 than against PDE6, which is found in the retina and is responsible for photo transmission. Tadalafil is also 10,000 times more active against PDE5, compared to its effect on PDE7-PDE10.

It works for 36 hours. The effect manifests itself after 16 minutes after ingestion in the presence of sexual arousal. Tadalafil in healthy individuals does not cause significant changes in systolic and diastolic pressure, compared with placebo in the supine position (the average maximum decrease is 1.6/0.8 mmHg, respectively) and standing (the average maximum decrease is 0.2/4.6 mmHg, respectively). Tadalafil does not cause a significant change in heart rate.

Tadalafil does not cause color recognition changes (blue/green), which is explained by its low affinity for PDE6. In addition, there is no effect of tadalafil on visual acuity, electroretinogram, intraocular pressure and pupil size. There was no clinically significant effect on sperm characteristics in men who took tadalafil in daily doses for 6 months.

Method of application and dosage

Middle-aged men are recommended to take a dose of 20 mg at least 16 minutes before the intended sexual activity, regardless of the meal. Patients can attempt sexual intercourse at any time within 36 hours after taking in order to establish the optimal response time to taking tadalafil. The maximum frequency of reception is 1 time / day.

Interaction with other drugs

  • Tadalafil is mainly metabolized with the participation of the enzyme CYP3A4. The selective CYP3A4 inhibitor ketoconazole increases AUC by 107%, and rifampicin reduces it by 88%.
  • Despite the fact that specific interactions have not been studied, it can be assumed that protease inhibitors such as ritonavir and saquinavir, as well as CYP3A4 inhibitors such as erythromycin and itraconazole, increase the activity of tadalafil.
  • With simultaneous administration of antacid (magnesium hydroxide / aluminum hydroxide) and tadalafil, the rate of absorption of the latter decreases without changing its AUC.

Tadalafil enhances the hypotensive effect of nitrates. This occurs as a result of the additive action of nitrates and tadalafil on the metabolism of nitric oxide and cGMP. Therefore, the use of tadalafil in patients receiving nitrates is contraindicated.

Side effects

  • Most often: headache, dyspepsia.
  • Possible: back pain, myalgia, nasal congestion, flushes of blood to the face.
  • Rarely: swelling of the eyelids, pain in the eyes, conjunctival hyperemia, dizziness.