Kamagra

Kamagra is a medicine used for erectile dysfunction. It contains the active ingredient sildenafil.

Indications Kamagra

Recommended for use by men who suffer from impotence – who are unable to achieve or maintain an erection in order to successfully engage in sexual intercourse.

To achieve the effect of the drug, sexual arousal is required.

Release form

The product is produced in tablets, 1 or 4 pieces in a blister. The pack contains 1 blister plate.

Kamagra jelly is available in 5 g sachets. Each pack contains 1 or 50 sachets.

Pharmacodynamics

Sildenafil is a drug taken orally that helps to get rid of impotence. When sexual arousal occurs, Kamagra restores weakened erection by increasing blood flow to the penis.

The physiological mechanism that causes an erection involves the release of the element NO inside the cavernous body, which develops during sexual arousal. The released element NO activates the enzyme guanylate cyclase, which stimulates an increase in the cGMP substance, and this leads to relaxation of the smooth muscle tissue in the cavernous body, helping blood flow to the penis.

Sildenafil is a potent selective inhibitor of the PDE5 component (the so-called cGMP-specific phosphodiesterase), which acts inside the cavernous body, where this element promotes the breakdown of the cGMP substance. The effect of sildenafil on erectile function is peripheral. The substance does not have a direct relaxing effect on the isolated cavernous body, but significantly potentiates the relaxing effect of the NO element on this tissue. During the activation of NO/cGMP metabolic pathways, which occurs during sexual stimulation, the slowing down of the PDE5 element by sildenafil increases cGMP levels inside the cavernous body. In this regard, in order to obtain the effect of sildenafil, it is necessary for a man to be in a state of sexual arousal.

In vitro tests have revealed the selectivity of sildenafil's effect on the PDE-5 element, which is an active participant in the development of an erection. Sildenafil's effect on PDE-5 is much more powerful than on other known PDE elements. It is 10 times more powerful than its effect on the PDE-6 element, which is a participant in phototransformation within the retina.

When taken in maximum permitted doses, sildenafil's selectivity for PDE-5 exceeds its selectivity for elements from PDE-2 to PDE-4 and from PDE-7 to PDE-11 by 80 times. For example, the selectivity of the component's action on PDE-5 is 4000 times higher than the selective effect on the PDE-3 component (this is a cGMP-specific isoform of the element that is involved in regulating contractile processes in the heart muscle).

Pharmacokinetics

Absorption.

Sildenafil is rapidly absorbed. It reaches its peak in plasma within 0.5-2 hours (median is 1 hour) – when taken orally on an empty stomach. The average level of bioavailability when taken orally is 41% (within 25-63%). Within the average permitted dosages (25-100 mg), the AUC values, as well as the peak concentration of the drug when taken orally, increase in accordance with the dose size.

If the drug is taken with food, the degree of its absorption decreases. The average time to reach the highest value is extended to 1 hour, and the level of peak concentration itself falls by 29%.

Distribution.

The average equilibrium values of the distribution volume are 105 l, from which it can be concluded that the drug is distributed inside the tissues. With a single oral administration of the drug in a 100 mg portion, the average value of the total peak concentration in the plasma reaches approximately 440 ng / ml (with a variability coefficient of 40%). Since the protein synthesis of sildenafil, as well as its main N-desmethyl decay product in the plasma is 96%, the average maximum value of the drug in the plasma reaches 18 ng / ml (or 38 nmol). The level of protein synthesis in the plasma does not depend on the total indicator of the substance.

In male volunteers who took the drug once in a dose of 100 mg, after 1.5 hours less than 0.0002% (average level – 188 ng) of the consumed substance was found in the ejaculate.

Metabolic processes.

The metabolism of the active substance occurs mainly under the influence of microsomal liver isoenzymes – elements of CYP3A4 (the main pathway), as well as CYP2C9 (the second pathway).

The main circulating metabolic product is formed by the process of N-demethylation of the active component.

The selectivity of this medicinal metabolite for the PDE-5 element can be comparable to that of sildenafil itself. The activity of the decay product for the PDE-5 element is approximately 50% of the activity of the active substance. The level of the metabolite in plasma is approximately 40% of that of sildenafil. The N-demethylated decay product then undergoes other metabolic processes, and its half-life is approximately 4 hours.

Excretion.

The overall clearance rate of the drug is 41 l/hour, with a half-life lasting 3-5 hours. The substance is excreted with its metabolites mainly in the feces (about 80% of the dose taken orally), and the remainder in the urine (about 13%).

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Dosing and administration

The medicine must be taken orally. To achieve the desired effect from taking it, a state of sexual arousal is required.

The standard adult dose of the drug is 50 mg. The drug should be taken approximately 60 minutes before the expected sexual intercourse. At the same time, taking into account the patient's tolerance and the effectiveness of the drug itself, the dosage can be increased to 100 mg or decreased to 25 mg. It is not allowed to take more than 100 mg of the drug.

The maximum permitted dosage of the drug can be taken no more than once a day. If you take Kamagra with food, its effect may begin a little later than when taking the tablet on an empty stomach.

Persons with renal insufficiency.

People who have this pathology in a moderate or mild form (with a CC level within 30-80 ml/minute) can take the medicine in a standard adult dosage.

People with severe forms of the disease (with CC values that do not reach 30 ml/minute) need to take 25 mg of the drug, because the clearance level of sildenafil in this case will be reduced.

Taking into account the patient's tolerance, as well as the effect of the drug, if necessary, it is allowed to gradually increase the dosage to 50 or 100 mg.

People with liver failure.

Due to the fact that people with this disease (for example, with cirrhosis) have a decrease in the drug clearance rate, they can take a maximum of 25 mg of the drug. It is necessary to gradually increase the dose by 2 or 4 times, taking into account the effectiveness of the drug, and at the same time its tolerability by the patient.

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Contraindications

Main contraindications:

• the presence of hypersensitivity to the active ingredient or other elements of the drug;
• combined use with NO donors (eg, amyl nitrite) or nitrate substances of various forms. Such use is prohibited, because there is evidence showing that sildenafil has a noticeable effect on the NO/cGMP metabolic pathways, and also significantly potentiates the antihypertensive parameters of nitrates;
• conditions during which sexual activity is prohibited (for example, in case of severe cardiovascular dysfunction – in case of angina with unstable manifestations or in case of severe stage of heart failure);
• loss of vision in one eye due to non-arteritic AION, regardless of the presence/absence of a connection between this disease and previous use of PDE-5 inhibitor drugs;
• the presence of the following pathologies: severe liver dysfunction, low blood pressure (below 90/50 mm Hg), recent myocardial infarction or stroke, and also diagnosed degenerative retinal diseases of a hereditary nature (for example, pigment retinitis; patients rarely have genetic lesions of the PDE in the area of the retina). This is due to the fact that the safety of taking the drug has not been studied in these subcategories of patients.

Kamagra is also not used by individuals under 18 years of age and women.

Side effects Kamagra

Taking the medication can cause the development of certain side effects:

• symptoms from the nervous system and sensory organs: dizziness with severe headaches, flushing of the skin of the face, increased sensitivity to light, impaired color perception and a feeling of blurred vision;
• Respiratory system disorders: nasal congestion;
• gastrointestinal disorders: manifestations of dyspepsia and diarrhea;
• skin disorders: appearance of rash;
• Others: back pain, respiratory infections, arthralgia and flu-like syndrome.

All the above negative reactions are usually expressed quite weakly and quickly pass.

Overdose

As a result of taking a 1-time dose of the drug up to 800 mg, negative effects occur similar to those observed when using the drug in lower doses, although they occur more often and have a higher degree of severity. The use of Kamagra in the amount of 200 mg did not increase the effectiveness of the drug, but led to an increase in the incidence of side effects (such as hot flashes with headaches, dyspeptic manifestations, nasal congestion, severe dizziness and problems with the visual organs).

If intoxication develops, standard supportive procedures must be performed. Hemodialysis will most likely not be able to accelerate the clearance of the drug, because the substance undergoes protein synthesis in large quantities within the plasma, and also due to the fact that sildenafil is not eliminated in the urine.

Interactions with other drugs

It is prohibited to prescribe the drug together with other drugs that increase potency, because this can lead to the development of intoxication.

It is also impossible to combine the drug with a number of drugs that affect cardiac function.

The medicine should not be taken with alcoholic beverages, because alcohol in large doses itself has a negative effect on erectile function. When combined with alcohol, the properties of Kamagra may be weakened.

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Storage conditions

Kamagra is stored in a place closed to small children. Maximum storage temperature is 30°C.

Special instructions

Reviews

Kamagra is an analogue of Viagra. According to reviews, the drug is quite effective, with a long duration of action, rarely causing side effects. Among the disadvantages, they note a fairly high cost.

Shelf life

Kamagra in tablets can be used for a period of 3 years from the date of manufacture of the drug, and in the form of gel/jelly - for a maximum of 2 years.