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Jul 18, 2006
Levitra vs Cialis vs Viagra
by SirGan|
There are several medications on the market which purpose is treatment of erectile dysfunction in men! These last couple of years, only three of them have separated from the others by their good effects and they are Levitra, Cialis and Viagra.
Which is the best- you must decide for you self? Everyone of them has its good and bad or side effects!
Levitra Levitra is an FDA-approved oral prescription medication for the treatment of erectile dysfunction in men. It is available in 2.5-mg, 5-mg, 10-mg, and 20-mg tablets and is taken only when needed. Mechanism of actionWhat exactly is penile erection? Well, penile erection is in fact one specific hemodynamic process initiated by the relaxation of smooth muscle in the corpora cavernosa-erectile parts of the penis. Then, during sexual stimulation, nitric oxide is released from nerve endings which then activates the enzymes resulting in increased synthesis of cyclic guanosine monophosphate smooth muscle cells of the corpora cavernosa. Why is this so important? This substance triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection.
Important thing to know is that main regulators of tissue concentration of cGMP are phosphodiesterases! Main ingredient of Levitra is the cGMP-specific phosphodiesterase type 5.
Levitra effectsSeveral studies have been conducted on the Levitra effects and side effects and most of the studies have showed that:
Levitra indications
Levitra contraindications
Several researches done in the past have came to the conclusion that administration of Levitra with nitrates and nitric oxide donors is contraindicated. A suitable time interval following Levitra usage for the safe administration of nitrates or nitric oxide donors has not been determined.
Reasonably, this medication is contraindicated for patients with a known hypersensitivity to any component of the tablet.
WARNINGS
Physicians should consider the cardiovascular status of their patients, since there is a degree of cardiac risk associated with sexual activity. In men for whom sexual activity is not recommended because of their underlying cardiovascular status, any treatment for erectile dysfunction, including Levitra, generally should not be used.
It is proven that patients with left ventricular outflow obstruction could be sensitive to the action of vasodilators including Type 5 phosphodiesterase inhibitors.
Levitra is systemic vasodilator which results in decreases in blood pressure in healthy volunteers. While this normally would be expected to be of little consequence in most patients, physicians should carefully examine their patients with underlying cardiovascular disease.
There have been rare reports of prolonged erections greater than 4 hours and painful erections greater than 6 hours in duration. In the event that an erection persists longer than 4 hours, the patient should seek immediate medical assistance.
Cialis – The “weekend pill” Most people already know that Cialis (Tadalafil) is a drug used to treat male erectile dysfunction. In the United States, Tadalafil has FDA approval and became available in December, 2003 as the third pill after Viagra and Levitra. This pill is famous due to its 36-hour effect. That’s why it is also known as the "Weekend Pill". Chemically it is almost identical to Levitra because it also belongs to the group of medications called selective inhibitors of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5).
Drug interactions
Because it is proven that PDE5 inhibitors such as Tadalafil may cause low blood pressure, it is recommended that organic nitrates should not be taken for at least 48 hours after taking the last dose of Tadalafil. It is proven that using organic nitrates within this timeframe may increase the risk of life-threatening hypotension.
Possible side effects of CialisSeveral researches done in the past have showed that several side effects can occur from using Cialis! Some of the most common are:
Other, less serious side effects may be more likely to occur.
Viagra Viagra , or to be more correct- Sildenafil citrate, is a drug used to treat male erectile dysfunction and pulmonary arterial hypertension. How these pills look like? Well, Viagra pills are blue and diamond-shaped with the words "Pfizer" on one side. Everyone knows that its primary competitors on the market are Cialis, and Levitra.
Mechanism of actionThe key point to understand is the fact is that substance called nitric oxide binds to the receptors of the enzyme guanylate cyclase which results in increased levels of cyclic guanosine monophosphate, leading to smooth muscle relaxation in the corpus cavernous. This is resulting in increased inflow of blood and an erection.
Similar to Cialis and Levitra-Viagra is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) which is responsible for degradation of cGMP in the corpus cavernous. This is resulting in better erections! Where it is metabolized? Well, it is proven that Sildenafil is metabolized by hepatic enzymes and excreted by both the liver and kidneys.
Contraindications and side effectsContraindications include:
Common side effects include sneezing, headache, flushing, dyspepsia, prolonged erections, palpitations and photophobia.
Viagra and Pulmonary hypertensionMost people don’t know but just as well as erectile dysfunction, Viagra is also effective in the rare disease pulmonary arterial hypertension. Several researches have proven that this medication relaxes the arterial wall, decreasing pulmonary arterial resistance and pressure, and reduce the strain on the right side of the heart thus improving symptoms of right-sided heart failure.
Viagra and Raynaud's phenomenonSeveral experts in this field have recently reported that Viagra cut the frequency of Raynaud's phenomenon attacks. Viagra reduced their duration by roughly one half, and more than quadrupled the mean capillary blood velocity. This phenomenon is about oversensitivity to cold!
Viagra and cognitive enhancementSeveral recent studies showed that Viagra may help to reduce and relieve cognitive deficits associated with aging. Although mechanism of this still isn't known- scientists found that in rats, administration of Viagra partially reversed the memory impairment.
Viagra and Analgestic propertiesSeveral studies have determined that Viagra demonstrates anti-nociceptive or pain-relieving properties in rodents. Current evidence seems to suggest that the cGMP that accumulates as a result of Phosphodiesterase 5 inhibition interacts with the cholinergic system to mediate this pain-reducing effect. That’s the only explanation with has at least some evidenced to back it up!
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