Preparations containing tadalafil
To date, there is one original drug containing tadalafil, which is called Cialis. In addition to Cialis, there is a fairly large range of drugs containing tadalafil as an active substance, which are generics. In principle, all these drugs will have the same therapeutic effect, so pharmacists consider them to be synonymous.
Today, the following preparations are available on the domestic pharmaceutical market that contain tadalafil as an active ingredient:
- Cialis 2.5 mg, 5 mg and 20 mg
- Cialis Soft 20 mg
- Tadalafil 40 mg (increased power)
- Cialis Tadrayz
- Tadagra softgel
The above drugs are synonymous drugs, therefore, have the same effect. Tadalafil dosages in them are also the same. Medicines are manufactured by various pharmaceutical companies and therefore have different names. In general, only Cialis is related to the original tadalafil preparations, and all other medicines are generics.
The substance tadalafil is chemical, that is, it is synthesized in test tubes. It does not occur in nature, therefore it is impossible to find this substance in any food product or medicinal plant. Specialists of the British pharmaceutical corporation Elly Lilly in 2003 developed a method for the preparation and chemical synthesis of tadalafil. Based on this substance, pharmacologists have created an original drug Cialis. All other drugs based on tadalafil are Cialis generics. Consider the main differences and characteristics of generics and original drugs.
In developing the original drug, the pharmaceutical concern synthesizes and releases a certain chemical substance, which will be the active ingredient. Then, experimentally identifies the optimal dosages of the substance in which it has the best positive effect with minimal side effects. Optimal auxiliary components are also installed. Then the technology of synthesis of the substance and methods of its purification from various impurities, which often cause allergic reactions and side effects, are being developed. After successful completion of all stages of development, the finished medicinal product is tested and marketed under a certain name, invented specifically for it.
Thus, original pharmaceutical preparations appear, which have international patents. However, a patent for a drug acts for a limited time, after which any pharmaceutical company can take the composition of the original drug (written in each instruction) and make its own medicine according to the indicated dosages. It is this drug will be called a generic. In rare cases, the generic comes up with a new name. And most often, generics are called simply by the international name of the active substance. For example, in relation to the active substance Tadalafil, it looks like this: the original drug is called Cialis, and most generics are Tadalafil. That is, the generic contains the same active substance as the original drug. Generics are usually much cheaper than the original drugs.
Despite the same active ingredient in generics and original drugs, the composition of auxiliary components may differ significantly. Often, in a generic, the only similarity with the original drug is only the same active ingredient. In this case, as a rule, for the production of generics, the active substances obtained in chemical laboratories by industrial means, which are not subjected to serious and thorough purification from impurities, are taken. It is a large amount of impurities that pharmacists mean when referring to a drug that it is quite "dirty".
Thus, Cialis has a large number of generics, which belong to the group of tadalafil. Most generics are produced by Indian pharmaceutical corporations, which, in principle, specialize in this particular area of the drug market. Hindus produce the following unusual generics:
- Cialis Soft – a tablet that can be chewed or rassasyvat, not drinking water
- Tadalafil 40 mg – a tablet that contains a large, "shock" dose of active ingredient
- Cialis gel – tadalafil in the form of a gel that is applied externally.
To date, speaking "Tadalafil"People most often mean the drug Cialis, which is the second most popular after Viagra. That is why in the future, when describing the properties of various drugs called "Tadalafil", we mean Cialis and all its generics.
Today, Tadalafil is available in the form of tablets with dosages of the active ingredient of 2.5 mg, 5 mg, 20 mg and 40 mg. As an active ingredient in drugs "Tadalafil" enters a chemical with the same name – tadalafil. The following substances are included in Tadalafil as auxiliary components:
- croscarmellose sodium
- microcrystalline cellulose
- magnesium stearate
- sodium lauryl sulfate
- titanium dioxide
Tadalafil tablets are almond-shaped, and on top are covered with a film shell, painted in yellow or red. On one side of the tablet there are engraved numbers indicating the dosage — that is, 2.5, 5, 20, or 40.
Tadalafil tablets in a dosage of 20 mg and 40 mg are available in packs of 1.2, 4, or 8 pieces. Tablets in dosages of 2.5 mg and 5 mg are available in packs of 14 and 28 pieces.
Therapeutic effect and effects
Tadalafil is a drug that improves male erection. The drug has the ability to influence key reactions that constitute a single process of sexual arousal and bringing the penis into an erect state. Usually, when a man is excited, the vessels of the penis greatly expand, a large amount of blood flows, causing the penis to become dense, that is, an erection occurs (or, in popular language, it "rises"). With various violations of erection there is a defect in the blood supply to the vessels of the penis. Tadalafil is a drug that enhances the blood filling of the penis, leading to a stable and good erection.
Enhanced blood filling of the penis occurs due to the expansion of blood vessels under the influence of a special substance – cGMP. But cGMP is rapidly destroyed by a special enzyme – cGMP-specific phosphodiesterase type 5 (PDE-5). Tadalafil inhibits (slows down) the work of PDE – 5, and as a result, cGMP does not disintegrate, but acts for a longer period of time, relaxing vessels and helping to fill the penis with blood to develop normal erection. Thus, in its clinical action, tadalafil is vasodilator , or vasodilator .
However, Tadalafil does not act independently; sexual stimulation and natural sexual arousal are necessary for the manifestation of its effect. The drug can not just make the vessels expand, fill with blood and, thereby, make the penis erect. The fact is that cGMP, necessary for the expansion of the vessels of the penis, is produced under the influence of nitric oxide (NO). And nitric oxide is released from the precursors only when a man begins sexual arousal. It is normal sexual arousal that leads to the sending of impulses to the corresponding centers in the spinal cord and brain, which send the command to release nitric oxide back through the nerve fibers. Thus, the release of nitric oxide leads to the production of cGMP, which directly expands the blood vessels and makes the penis erect. And Tadalafil can only strengthen and prolong the action of cGMP, which should be formed under the influence of natural sexual arousal through nitric oxide.
By prolonging the effect of the secondary mediator cGMP, Tadalafil makes the erection more pronounced and prolonged. But for the manifestation of this action of the drug, it is necessary to induce the production of the cGMP molecule, for which it is enough to excite at the level of a simple and natural desire for sexual intimacy. In this case, Tadalafil will support male activity and give a good erection to the penis, which is enough to conduct a full-fledged love act. But in the absence of sexual arousal, Tadalafil will not be able to bring the penis into an erect state, since the drug only strengthens and prolongs the natural process. The drug itself can not completely artificially create sexual arousal and cause an erection in a man.
PDE enzymes are present not only in the vessels of the penis, but also in the arteries of the retina, skeletal and cardiac muscle, lungs, etc. PDE in each organ is designated by a specific number, for example, PDE – 5 is an enzyme working in the penis vessels, PDE – 6 is localized in the retina, and PDE – 3 in the heart muscle. Tadalafil has a high specificity, and therefore acts selectively only on PDE-5. That is why the drug has no such side effects as effects on pressure, color changes, etc. These side effects are found in Viagra (Sildenafil), which does not have as high specificity as Tadalafil.
Tadalafil has an effect within 36 hours from the moment of taking the pill. The effect of the drug develops 16 minutes after taking the pill with good sexual arousal. Tadalafil does not affect blood pressure either in the prone position or in the standing position. Also, the drug, unlike Viagra, does not change the heart rate, does not affect color perception, visual acuity, intraocular pressure and pupil size. In addition, Tadalafil, improving erection, does not affect the quality of sperm and sperm.
Indications for use
Tadalafil has absolute and relative contraindications. In the presence of absolute contraindications, the drug is forbidden to use in any circumstances. And in the presence of relative contraindications Tadalafil can be used with caution and under careful control over the state of human health. The relative and absolute contraindications are reflected in the table: