Viagra vs Cialis, which is better?
At present, preparations such as Viagra (Sildenafil) by Pfizer Incorporated and Cialis (Tadalafil), fruit of the collaboration between Eli Lilly Pharmaceutical Company and YCOS Incorporated, are widely used for the treatment of erectile dysfunction (ED). The first entered the market in 1996, while the second was launched in 2003.
The action mechanism of both preparations consists in phosphodiesterase type 5 (PDE 5) enzyme inhibition that metabolizes 3`:5`-cyclic guanosine monophosphate (GMP), which is responsible for penis erection. To maintain the necessary GMP level they used a routine method consisting in the inhibition of the enzyme that splits GMP.
The data on the pharmacokinetics of these preparations are in favor of Cialis. Thus, the period of Viagra’s effective half-life is about 3 – 5 h (depending on dosage), while that of Cialis is 17.5 h. Viagra is effective for maintaining an erection for 4 h, while Cialis (20 mg) works for 36 h.
The side effects of Viagra and Cialis are quite similar: vertigo, headaches, diarrhoea, nausea, symptoms of the flu (stuffy nose), hot flashes, backache, stomach ache, and arthralgia.
Although these side effects were transient and benign, or sometimes moderate, the makers of the Cialis preparation noted a decrease of intensity in cases where the drug was taken over a longer period of time. Both preparations are contraindicative in men taking nitro preparations.
While Viagra is the first generation preparation and has been in the market for 5 years, there are some facts against it. In July 2002, Harold Millman, an American toxicologist, published the results of Viagra side effects research in Annals of Pharmacotherapy. The users of the preparation experienced vertigo, disorientation, amnesia. Twenty-two men (out of 270) suspected that Viagra stimulates aggression, 13 that it provokes violence, and 6 people asserted that taking Viagra had given rise to a strong desire to kill someone. These side effects became evident when the maximum dozes of the preparations were taken.
Another source (Illustrated Thesaurus, Sex) pays attention to the incompatibility of Viagra with alcohol. The overdosing of Viagra cost the lives of many pensioners. Among the side effects are neuropsychiatry (high aggression), fatal outcome (more than 1000 cases were registered), and paralysis. Researchers of Cialis noted the absence of restrictions to taking the medicine with food and alcohol, which heightens the ease and meets the patients’ needs in terms of their way of life.
An analysis of the existing facts about the characteristics of Viagra and Cialis allows us to give preference to the latter. Nevertheless, you should not forget that this preparation is new in the pharmaceutical market and the appearance of some additional information about its pharmacological and other features is inevitable. Read more about Viagra vs Cialis
Preparations for Erectile Dysfunction Treatment
A revolutionary event in the sphere of erectile dysfunction treatment was the emergence of Sildenafil Citrate in 1996, which achieved fame under the brand “Viagra”. This preparation, taken in the form of pills, improved the effectiveness of treatment and allowed physicians to help their patients suffering from ED. However, a lot of men, especially those with a serious form of ED, diabetes, hypertension, and patients having had radical prostatectomy, are not fully satisfied with the existing treatment. Furthermore, the effectiveness of Sildenafil depends on food and alcohol, which quite often accompany sexual relations. This in turn creates certain problems when it comes to planning sexual intercourse. These circumstances led to the fact that about 50% of patients taking Sildenafil are determined to continue treatment.
The next approved PDE 5 inhibitor after Sildenafil was the Cialis preparation (Tadalafil). As opposed to Sildenafil, this preparation has prolonged the effective half-life (17.5 h) and its pharmacokinetics do not depend on food and alcohol. Thus, the duration of the Cialis effect (36 h) makes it possible to forget planning coitus and save the spontaneity and romanticism of sexual relations. Most recent research shows that only 13% of patients with ED surveyed are interested in the longevity of the preparation’s effect; they are generally interested in the safety (40%) of the therapy they get. Moreover, some patients taking Tadalafil noted side effects such as back aches during throughout the period of the preparation’s effect. Cialis is produced in one dosage (20 mg), which creates certain problems related to therapy correction depending on the effectiveness and tolerance of the preparation.
Hence, a certain quantity of patients are unsatisfied with their previous ED treatment and patients with undiagnosed and uncured erectile dysfunctions need a new, more effective preparation. The ideal therapy in case of ED is non-invasive, i.e. implying the taking of peroral preparations, a safe treatment that is equally effective for everyone. All the enumerated demands are met in the case of Levitra (Vardenafil Hydrochloride) – a new, highly effective and most powerful PDE 5 inhibitor to date. Vardenafil is much more powerful than Sildenafil in terms of influence on PDE 5. Vardenafil has less impact on the light sense in comparison with Sildenafil and on spermatogenesis in comparison with Sildenafil and Tadalafil.
Vardenafil is easily absorbed; the maximum level of the preparation’s concentration in the blood plasma is achieved in 30 minutes after peroral taking. The duration of the Levitra effect is 4 – 5 h, which is enough to have a full-blown coitus. Furthermore, this preparation is not accumulated in the organism. This is the main difference between it and Tadalafil, the partial ejection of which is quite prolonged and is the reason of some undesired effects in the case of everyday intake. Food and alcohol do not influence the effectiveness of the preparation.
Research carried out recently has showed that Vardenafil is a high-performance (85 – 89 %) and safe preparation for ED treatment. The more powerful impact of this preparation on PDE 5 allows us to use it not only in combination with other forms of treatment, but even in case when other inhibitors PDE 5 (Sildenafil, Tadalafil) are not effective. The effect of Levitra in patients suffering from diabetes and those emerging from radical prostatectomy figures at 72%, while in those who have taken Sildenafil it amounts to 62%.
The side effects of taking Levitra are short-term and insignificant in most of cases.
Due to these qualities of the preparation, namely its quick and marked effect not depending on food and alcohol intake, patients will be able to plan sexual intercourse any time they want. The preparation is produced in three dosages (5, 10, 20 mg) which allows physicians the possibility of correcting therapy depending on its effectiveness and tolerance. These and other differences between it and Viagra, such as the absence of the tachyphylaxis effect (the lowering of the effectiveness in case of prolonged therapy), are the cause of great expectations in the case of prolonged ED therapy.
To conclude, the existing preparations for ED treatment allow getting positive results in the majority of patients. Unfortunately, there are some patients with ED in case of whom any pharmacotherapy is ineffective. In such patients other kinds of treatment are used (combined peroral and intracavernous therapy, vacuum therapy and surgical methods of treatment).
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