Penigra

Penigra contains the component sildenafil, which is its active ingredient. It selectively inhibits the action of the cGMP-specific component of PDE-5.

The physiological process of the development of an erection of the penis is associated with the release of NO within the corpus cavernosum in connection with the exposure to a sexual stimulus. The NO component helps to activate the guanylate cyclase enzyme, as a result of which the cGMP level increases, and the smooth muscles of the corpus cavernosum relax, followed by the potentiation of blood flow to them. [1]

Indications Penigra

It is used in men in case of developing erection problems .

Release form

The release of the therapeutic element is made in tablets - 1 or 4 pieces with a volume of 50 or 100 mg inside a cell package. Inside the pack - 1 such package.

Pharmacodynamics

Sildenafil does not show a direct relaxing effect on the muscles of the corpus cavernosum, but potentiates the effect of NO, slowing down the activity of PDE-5. It must be borne in mind that in the absence of a sexual stimulus, sildenafil will have no effect.

In volunteers who took sildenafil 1 time in a portion of 0.1 g, there were no clinically significant changes in the ECG readings. As a result of its use, there was a moderate or weak decrease in the level of blood pressure, which did not affect the drug efficacy. A more significant decrease in blood pressure was observed in people who took the drug together with nitrates. [2]

Pharmacokinetics

Sildenafil citrate is absorbed at high speed when administered orally; its bioavailability is about 40%. The pharmacokinetic parameters of a substance depend on the portion size (within the therapeutic spectrum).

Indicators of plasma Cmax are observed after 0.5-2 hours (on average - 1 hour) after ingestion on an empty stomach. Taking drugs together with fatty foods causes a decrease in the intensity of absorption, which is why it takes an average of 1 hour longer to obtain Cmax.

The average values of the distribution volume (equilibrium) for sildenafil are 105 liters.

The metabolic processes of the element proceed with the participation of hepatic isoenisms CYP3A4 (the main method), as well as CYP2C9, after which it is transformed into the active metabolic component N-desmethylsildenafil, which has properties similar to sildenafil. The plasma level of this metabolite is approximately 40% of that recorded for sildenafil. As a result, the specified element has almost 20% of the therapeutic effect of sildenafil. Both of these components are approximately 96% synthesized with protein.

The half-life of these substances is 4 hours. The systemic clearance of sildenafil is 41 l / h, and the half-life is 3-5 hours. The excretion of sildenafil metabolites is carried out mainly with feces (about 80% of the ingested portion), and a smaller part of them with urine (13% of the dosage).

Dosing and administration

Penigra is usually taken in a 50 mg serving, approximately 1 hour before sexual intercourse. In general, the permissible range of application before sexual intercourse is 4-0.5 hours. Taking into account the effect and the patient's response, the dosage can be increased to the maximum daily dosage (0.1 g) or reduced to the minimum (25 mg).

Consumption with food leads to a slowing down of the effect of the medication compared to administration on an empty stomach. Also, for the development of exposure to drugs, a sexual stimulus is required.

Factors that increase the plasma level of the drug: age over 65 years, liver or kidney failure (CC level <30 ml per minute), as well as a combination with substances that slow down the action of hemoprotein P4503A4 (among these are erythromycin with ketoconazole, saquinavir and itraconazole).

Because with an increase in plasma values, the effect of drugs and its side effects can be potentiated, patients with risk factors should first use a portion of 25 mg.

• Application for children

The medication is not used in pediatrics.

Use Penigra during pregnancy

Penigra is not prescribed for women.

Contraindications

Because the drug potentiates the antihypertensive effect of amyl nitrate and other nitrates, it is not prescribed to persons using these substances or organic nitrates of any type (constantly or according to a different scheme).

You can not use the medication in the presence of intolerance to any element of the tablets.

It is contraindicated to prescribe to people who are undesirable to have sex (for example, people with severe stages of CVS pathologies, including intense heart failure and angina of an unstable nature).

Side effects Penigra

Side effects often develop when the dosage is increased. Among those: dyspepsia, visual disturbances, headaches, increased photosensitivity, epidermal hyperemia, chromatopsia, rash, swelling in the nasal mucosa, dizziness and diarrhea.

In some patients, 60 minutes after taking 0.1 g of drugs, a weak and transient color perception disorder (associated with green and blue colors) developed, which disappeared after 2 hours.

In flexible dosage testing, digestive disturbances were more likely than at lower doses with a 0.1 g serving.

During the post-registration term, with the introduction of the drug, such single or atypical symptoms were noted:

• immune manifestations: signs of intolerance (among them an epidermal rash);
• lesions associated with the work of the CVS: syncope, tachycardia, decreased blood pressure and nosebleeds;
• digestive problems: vomiting;
• visual disturbances: redness or pain in the eye area.

Prolonged (more than 4 hours) erection, as well as priapism, are observed after the use of sildenafil only occasionally.

Overdose

Testing with volunteers showed that with the introduction of 1-fold portions up to 0.8 g, the cases of development of negative signs were similar to the symptoms observed at weaker dosages, but the number of such cases and their severity was higher.

In case of poisoning, standard supportive measures are taken. Renal dialysis procedures do not accelerate the elimination of the drug, because sildenafil is strongly synthesized with plasma protein and is not excreted in the urine.

Interactions with other drugs

The administration of sildenafil together with drugs that specifically slow down the action of CYP3A4 (erythromycin and ketoconazole with itraconazole), as well as substances that nonspecifically slow down the activity of CYP (cimetidine), leads to a decrease in the level of its clearance.

The use of the drug and drugs that induce the action of CYP3A4 (rifampicin) causes a noticeable decrease in the plasma parameters of the former.

In addition, the plasma level Cmax of sildenafil increases when combined with saquinavir (it slows down the activity of CYP3A4).

It is forbidden to use in combination with ritonavir, which slows down the effect of P450, because it causes a change in the pharmacokinetics of sildenafil.

Grapefruit juice slightly slows down the action of CYP3A4, therefore, it may slightly increase the plasma values of the drug.

The introduction of 0.1 g of Penigra in combination with amlodipine leads to a decrease in the values of diastolic and systolic pressure, respectively, by 7 and 8 mm Hg.

AT decreases in the case of a combination of a medication (in a 25 mg portion) with a substance that blocks the action of α-adrenergic receptors (doxazosin in a 4 mg portion) in persons with benign prostatic hyperplasia.

Storage conditions

The penigra should be kept out of the reach of small children, at temperatures up to a maximum of 25 ° C.

Shelf life

Penigra can be used for a 36-month term from the date of manufacture of the therapeutic agent.

Analogs

The analogues of drugs are Viagra, Lovigra and Superviga with Eroton, as well as Conegra and Viafil.