Viagra vs Cialis vs Levitra (ED pills comparison part 2)
Viagra vs Cialis vs Levitra part 2 of ED pills comparison
Viagra vs Cialis vs Levitra half-lives
Phosphodiesterase type 5 inhibitors remain effective for different lengths of time and this is expressed in ‘half-lives. Cialis has a half-life of 17.5 hours. If a sufficient dosage is taken it can remain effective for up to 36 hours. Levitra and Sildenafil have a half-life of approximately 4 hours. It has an effective footprint of up to 8 hours if a large enough dosage for the subject is digested.
PDE5 inhibitors are removed from the blood stream via hepatic metabolism. The metabolite N-desmethyl is the by-product of metabolised Sildenafil. This also exhibits PDE5 blocking characteristics. Up to 20% effective of Sildenafil itself. The metabolite remaining from Levitra in comparison only has a 7% effectiveness of the initial PDE5 inhibitor. Cialis exhibits no active metabolites subsequent to breakdown.
The body eliminates all oral phosphodiesterase type 5 inhibitors via normal bodily excretion.
Viagra vs Cialis vs Levitra – testing PDE5 inhibitor time delay in effectiveness
Neither Sildenafil, Levitra nor Cialis are effective immediately after consumption. Test results have shown that there is considerable variation between these 3 PDE5 inhibitors. There are also considerable differences among the test subjects in this regard.
On average all 3 PDE5 inhibitors become active between half an hour to 1 hour after ingestion. However, researchers noted considerable divergence outside these time parameters.
Medical and pharmaceutical industry recommends 60 minutes between taking Sildenafil orally and its time of most effectiveness.
However, one study showed that 35% experienced the effectiveness of Sildenafil within 15 minutes.
In another study, 20% of test subjects had erections within 10 minutes after taking 10mg of Vardenafil. The standard recommendation for Vardenafil is to take it 25 to 60 minutes prior to intercourse.
The standard recommendation for Cialis is to take it at least 30 minutes before intercourse. One study has shown that 16% were able to preform intercourse in under 20 minutes.
Viagra vs Cialis vs Levitra – duration of effectiveness
The three PDE5 inhibitors used in Viagra, Levitra and Cialis have different lengths of duration in their effect. Standard information supplied with Levitra and Sildenafil suggest a 4 to 5 hour duration when the treatment remains effective.
Tadalafil on the other hand has a half-life of 17.5 hours. Researchers consider the effects of Cialis and other Tadalafil-based ED treatments effective for up to 36 hours. Hence the nickname ‘the weekend pill’. This length of effective duration makes Tadalafil a top choice.
Tests have shown that all 3 PDE5 inhibitors are effective for a broad spectrum of subjects. Currently there still is a lack of direct comparative tests of the ED medications Levitra, Cialis and Viagra. Researchers need more head to head comparative tests of these PDE5 inhibitors. Then researchers can determine a definitive pronouncement of their effectiveness.
Viagra vs Cialis vs Levitra – efficacy tests
Beneficial change arising from a 3 month trial of taking theses ED treatments involving between 150 subjects on Levitra, 320 subjects on Viagra and over 1,000 subjects taking Cialis. It resulted in the following figures:
75% of the subjects who took 50 mg of Viagra reported an improvement of erections over the course of the test. Only 16% of those who took a placebo reported and improvement.
For those who took 20mg of Levitra over a 3 month period, 82% reported an significant improvement. In the same test 39% of subjects who took a placebo reported a similar improvement.
All the subjects where in their late 50’s. They had previously experienced levels of erectile dysfunction ranging from mild to severe for up to 6 years previously.
In another 12 week study of the efficacy of Cialis, 84 percent of test subjects reported an significant improvement. Of those taking a placebo, 33% reported an improvement.
These studies included men in their late 50’s who had suffered erectile dysfunction for more than 1 year. The degree of erectile dysfunction suffered by the patients ranged from moderate 45% to severs 65%.
Test subjects who had previously failed to respond to PDE5 inhibitors were excluded from these trials.
In the tests cited above it was asked: Was your erection of sufficient strength and duration to have full intercourse? A positive response to this question was 65% for Viagra and Levitra, and 68% positive for Cialis.
Viagra vs Cialis vs Levitra in patients with health conditions and other medications
The use of PDE5 inhibitors are effective with those who suffer from diabetes, clinical depression and cardiovascular disease.
Studies were in accord with the European regulatory framework for prescription medications. All three used PDE5 inhibitors, Levitra, Cialis and Viagra. They can be used to treat patients with cardiovascular disease with the proviso that they have currently taking nitrates.
One test result indicated that there was a 71% success rate for patient who tried a PDE5 impotence treatment who were also at risk for cardiovascular disease.
There is a caution in place however against using Viagra while at the same time being on alpha blockers for hypertension. Combining these to prescription increases the risk of suffering hypotension. Experts do not recommend doses of Viagra over 25mg for those currently on a daily dosage of alpha-blocker medication.
Many consider Levitra potentially beneficial for those patient with hypertension and cardiovascular problems. There has yet to be definitive tests results to back this association.
Researchers do not recommend combining alpha blockers with Levitra. Not until the subject has achieved a fixed regime of alpha blocker intake and their condition is stable.
Researchers recommend that the maximum dose of Vardenafil is kept to 5mg. Even this modest dosage of this PDE5 inhibitor one should not take one within 6 hours of alpha blocker ingestion.
Similar to Levitra, Cialis has similar benefits for men with erectile dysfunction and hypertension issues and those with cardiovascular risk factors.
The European Union recommends that alpha blockers and Tadalafil (Cialis) should not be taken in conjunction.
Despite this, one study involving around 20 subjects showed that Cialis had no measurable impact on blood pressure.
Viagra vs Cialis vs Levitra – effects of on men with diabetes
PDE5 inhibitors such as Viagra, Cialis and Levitra are effective in men who suffer from ED and diabetes. After being treated for ED with Viagra well over 50% of the subjects of this group reported improvement in erectile function. Also ability to engage in sexual intercourse for a sustained period. Doses of Viagra ranged between 25mg and 100mg. This allowed the subjects of this group to choose for themselves what they felt to be appropriate based on results and how well the subjects in question tolerated this PDE5 inhibitor.
In a similar group of tests subjects, those who suffered from both ED and diabetes, comparable benefits where had with Levitra and Cialis with a 20 mg dose. Tests showed a 71% and 65% success rate with these PDE5 inhibitors respectively.
Viagra vs Cialis vs Levitra – similarity of negative side effects
Adverse side effects of all three of the most popular PDE5 inhibitors and their prescription pill counterparts, Viagra, Cialis and Levitra, are roughly similar.
As an effect of the vasodilatory effects of these treatments some people experience myalgia, nasel congestion, headaches and dyspepsia.
Another negative side effect associated with the us of these PDE5 inhibitors is hypotension, or when the blood pressure become too low resulting in dizzy spells and lack of stamina. This is most likely when subjects take these PDE5 inhibitors in conjunction with nitrates of nicorandil, a potassium channel blocker. As a result, researchers do not recommend combining PDE5 inhibitors with nitrates or nicorandl.
The differences in selectivity between Cialis, Viagra and Levitra, may account for the differences in side effects. Also when it comes to considering side effects in the operation of the optic nerves.
Occasional reports indicate that some subjects experienced non-arteritic anterior ischaemic optic neuropathy, NAION. It resulted in a temporary loss of vision in a single or both eyes. As a result the US Food and Drug Administration requires all labels to advice health care professionals to desist in proscribing PDE5 inhibitors to patients who experience a loss in vision. However, there have yet to be verifiable test results that conclusively tie the use of PDE5 inhibitors with temporary loss of vision.
Viagra vs Cialis vs Levitra – failure of response rate
Not all men who experience chronic erectile dysfunction respond positively to PDE5 inhibitors.
Test studying failure rates of popular ED medications like Cialis, Viagra and Levitra do not consider it a permanent failure to respond until the maximum dose of each PDE5 inhibitor fails for 8 or more consecutive time.
One study involved over 130 subjects. Failure to respond to Viagra was turned into responsiveness after psychological therapy for over 50% of the subjects. Sujects must experience sufficient sexual arousal prior to experiencing the beneficial effects of PDE5 inhibitors.
Additionally, researchers found that some men who remain unresponsive to some PDE5 inhibitors are responsive to other ones – although the reasons remain unclear.
However, some men who fail to respond t PDE5 inhibitors initially discover that a continuous expose to these ED medications can result in a decrease of ED symptoms over a course in time
Another reason some subject fail to respond to popular ED medications such as Viagra or Cialis is due to a dearth of the hormone androgen. Researchers do not recommend ED medications for cases androgen replacement therapy.
Researchers recommend that referral to specialists is the best course of action for those who do not respond adequately to oral phosphodiesterase type 5 inhibitors.
Viagra vs Cialis vs Levitra – Impotence treatment goals and preferences
The main goal of ED treatments like Viagra, Cialis and Levitra is to restore full erectile capacity when sexually stimulated as a consequence to enjoy a full and satisfying sex life.
Medical professionals must note the needs and individual preferences of the patient when prescribing the available ED medications.
Given that the response rate and effectiveness of the three major PDE5 inhibitors are similar, the preferences of the patient must be duly considered prior to continuing prescription.
Preferences for Tadalafil over Sildenafil
To measure patient preference between Tadalafil (Cialis) and Sildenafil (Viagra), researchers used a double-blind crossover test study with 200 subjects. The doses were a flexible dose of Viagra and 20 mg of Tadalafil for the Cialis.
Those taking the Viagra started on 50 mg with the option to increase the dose limited to 35% of the test subjects to repeat patterns found in clinical practice.
Due to the fact that instruction regarding duration for Cialis and Viagra are different, researchers used placebos mimicking both medication instructions to maintain blindness and impartiality.
There was also a random selection as which subjects received Cialis and Viagra with a 12 week crossover from.. At the end of the study 180 subjects could make a choice over which ED medication they preferred.
At the end of the blind test researchers discovered that approximately 70% of the test subjects clearly chose Cialis vs Viagra as their preferred ED medication
Another study where Cialis is preferred
Another study involved patients experimenting with doses of Viagra ranging from 25 mg to 100 mg for a period of 6 weeks Then they switched over to Cialis at a fixed dosage of 20 mg.
This test attempted to mimic normal clinical practice. The results showed definitively that around 90% of the test subjects chose to continue with Cialis vs Viagra.
In another study conducted in Europe tested the preference for Viagra vs Cialis. Over 350 subjects participated. The trial lasted 12 weeks for each PDE5 inhibitor.
The first 8 weeks trying either Viagra or Cialis was the ‘dose optimisation’ phase. The subjects established the best dosage amounts for each respective PDE5 inhibitor. The subjects started with 25or 50 mg of Sildenafil. They could then up the dosage to 100 mg if they chose to. Subjects also started with 10 mg of Cialis and could up the dosage to 20 mg if they chose to.
Researchers gave the subjects a choice on which ED medication they would choose to continue with after both 12 week phases with Viagra vs Cialis
30% prefer Viagra, 70% prefer Cialis
30% of the subjects chose to continue with Viagra and 70% chose to continue with Cialis.
The choices made did not influence the order or sequence of testing, degree of erectile dysfunction experienced beforehand, the subjects age or dosage desired. 3% of the test subjects discontinued due to adverse effects and .08% discontinued due to lack of any beneficial effect.
These two studies clearly demonstrate that users select their preferred ED treatment based on pharmacological considerations. However the methods used in these studies of ED medication user preference employ methods that could introduce some bias in decision making among the subjects of the study.
Methodological problems include gaps in double blinding, adapt ion effects over time, sequence order of crossover, and multiple dosage strengths and instructions. Instructions vary due to the differences in half-life, duration and effect of food upon the performance of Cialis and Viagra.
Subjects understood dosage instructions appropriate for the PDE5 inhibitor tested (Cialis or Viagra) at that phase. It seems unlikely that any adverse reaction of or experience of its efficacy were effected by the methodology of the test.
Even though this test conducted by Eardley et al. accounted for potential biases more comprehensive studies will determine user preference of the three major PDE5 inhibitors Tadalafil (Cialis), Vardenafil (Levitra)and Sildenafil (Viagra).
ED pills comparison summary
Following from the popularity and uptake Viagra the overall complexity and cost of erectile dysfunction management procedures have fallen considerably.
All three available PDE5 inhibitors are an affordable way to treat the vast majority of ED cases. Being effective for a far longer period, Cialis may seem the more cost-effective ED treatment particularly if the user intends on using it in a long-term capacity over many years.
When it comes to ED treatment, oral PDE5 inhibitors remains the most effective, easy to administer, and affordable choice. All 3 of the main PDE5 inhibitors, Vardenafil, Tadalafil and Sildenafil share similar characteristics. All 3 are effective and well tolerated by the vast majority of users.
It is important however that the medical establishment keeps in mind the differences among these PDE5 inhibitors when prescribing these ED treatments to particular patients. Only then can it be assured that each patient derives the best match for his needs in order facilitate the restoration of his natural and healthy sex life.
Regarding Viagra vs Cialis vs Levitra, Cialis is the clear winner. However ED pills comparison studies indicate that in many instances Levitra or Viagra may be the better choice.