ED medication comparison of erectile dysfunction treatments Viagra, Cialis and Levitra.
Tackling impotence with Phosphodiesterase Type 5 (PDE5) Inhibitors
The following ED pills comparison study examines the all aspects of the 3 most prescribed ED treatments. These 3 PDE5 inhibitors are the basis of popular ED pills Viagra, Cialis and Levitra.
Tadalafil is the active ingredient in the ED medication Cialis®, manufactured by Eli Lilly. It is the longest lasting of the 3 main ED medications.
Sildenafil is the active ingredient of the ED medication known as Viagra®, a registered trademark of Pfizer who also manufactures this well-known brand. In 1998 Viagra achieved FDA approval for this first erectile dysfunction in 1998.
Vardenafil, another PDE5 inhibitor is the active ingredient Levitra®, manufactured and distributed by Bayer Pharmaceuticals, a German company most known for its flagship medication Asprin.
The stigma surrounding the condition of erectile dysfunction is dissipating
The discomfort around the treatment of ED, is still present but currently, has decreased. This improvement, to some extent, was a result of the introduction Viagra in 1998 that altered erectile dysfunction treatment. Since then, the popular knowledge of impotence has increased, as has the requests for treatment of impotence.
Concerning the current choices to treat ED, oral phosphodiesterase type 5 (PDE5) inhibitors such as Sildenafil (Viagra), Tadalafil (Cialis) and Vardenafil (Levitra) are the proven method. This ED pills comparison will deal with these three ED treatments currently widely available.
As outlined above, this review compares a number of currently licensed PDE5 inhibitors such as Sildenafil citrate, Vardenafil HCl and Cialis.
All these pills have common effects and structural make-ups. Viagra and Levitra have related molecular characteristics. Cialis is molecularly different in its pharmacokinetic arrangement. This maks ED pills comparison a relatively straightforward project.
ED pills comparison – differences between Viagra, Levitra and Cialis
Capability to enjoy an erection that leads to sexual penetration works for 36% of subjects treated with Viagra in 14 minutes. 24% of men who took Levitra within 11 minutes. 17% of men given Cialis within 15 minutes.
Viagra and Levitra both suffer from half-lives of 4 hours but the half-life of Cialis is around 17 hours.
An additional difference between the PDE5 inhibitors is that meals, especially fatty food, modifies the effectiveness of Levitra and Viagra, but not Cialis.
The different pharmacokinetic characteristics among the oral PDE5 inhibitors could influence user choice, an important and emerging aspect of ED pills.
The arrival of Cialis and Levitra extended the number of options for ED treatment. These treatments share the same method of action as Viagra.
This expanded choice of ED pills allows doctors to consider how they compare in terms of efficacy, safety and convenience.
This ED pills comparison considers this issue by offering a comparative analysis of 3 PDE5 inhibitors: Vardenafil, Sildenafil and Tadalafil.
Erectile dysfunction overview
Erectile dysfunction is a failure to achieve an erection of sufficient stiffness for intercourse. It is often due to aging. It becomes more common in men aged forty and older.
In the past, doctors assumed that erectile dysfunction was a mental issue or just a part of getting older. They tolerated ED with other manifestations of age. Now they know that erectile dysfunction is chiefly due to vascular neurological complications.
Erectile dysfunction can also be a marker of many lesser known physical ailments. For example, men with vascular disorders, cardiovascular disease and diabetes. These ailments can cause a high incidence of impotence.
Crucially, impotence may frequently prove to be an important marker for undiagnosed organic diseases including:
- ischaemic heart disease,
- neurological conditions
- endocrine disease.
Despite greater awareness, erectile dysfunction still remains insufficiently diagnosed and treated by the medical establishment. The stigma associated with erectile dysfunction has decreased, but the discomfort of men confiding in their sexual problems continue to form a barrier to sufficient diagnosis and treatment of ED.
The awkwardness many patients and medical establishment workers feel awkward in openly discussing sexual dysfunction. This fact delays the best diagnosis and treatments available. As a consequence, many men suffer varying degrees of ED prior to seeking treatment.
Too many governmental health boards give scant attention to ED. As a result not enough research funds come available to study the condition and its treatments.
Most men who suffer ED are fail to secur sufficient treatment. Many in the medical establishment view this as a lost opportunity to improve men’s overall health, not just ED.
This ED pills comparison review will help address that imbalance. It assists both impotence sufferers and those in the medical establishment a clearer idea of the solutions now available.
The role of PDE5 inhibitor ED treatments
Doctors realize that ED medications improve the overall quality of life of the patient. They restore the sexual stamina of the patient to a former state. In order to facilitate more natural forms of sexual expression there is a preference for long lasting erectile dysfunction treatments.
Lifestyles changes for obese subjects are beneficial. It improves sexual function and decrease rates and severity of erectile dysfunction.
Healthy alternatives to erectile dysfunction medications
One study involving 138 men found that for one-third, simply lifestyle changes improve sexual performance. The 2 most important factors were weight reduction and increased cardioid-vascular activity.
However, the majority the erectile dysfunction levels of a majority of subjects did not significantly improve through lifestyle changes. This underscores the fact that ED treatments can do more to effectively overcome impotence in the wider population.
Intrusive alternatives to oral PDE5 inhibitors (ED pills)
Various treatments for erectile dysfunction, including surgery, pumps, injections and internal splints exist. Understandably most men prefer less intensive ED treatments and tablets are usually the first choice. As a result doctors rarely prescribe the more intrusive treatments for ED. More affordable and effective PDE5 inhibitors are now readily available.
Oral treatments such as Viagra, Levitra or Cialis are easy to take as well as having minimal side effects. They all have a high rate of effectiveness. WHO now stipulates these oral treatments as the preferred treatment of ED in the first instance.
The ED treatments with most success are Viagra, Levitra or Cialis. As a consequence both expectations and successful outcomes of ED treatments have increased.
PDE5 inhibitor Sildenafil marketed as Viagra
The first oral PDE5 inhibitors available was Sildenafil: Viagra, generic Viagra and other brand names such as Kamagra. After the introduction of Viagra, a range of PDE5 inhibitors has become available. Cialis (Tadalafil) and Levitra (Vardenafil) both having slight different characteristics from the original Viagra.
Doctors prefer PDE5 inhibitors as first treatment for erectile dysfunction. Experts do not recommend these PDE5 inhibitors for men who have previously suffered stroke as well as a host of other medical conditions – such as:
- kidney disease that requires dialysis;
- cardiac failure; out-of-control hypertension;
- seriously low blood pressure;
- significant liver damage;
- those who have a history of myocardial infarction and angina.
ED specialists recommend doctors consult the detailed information and prescription recommendations for each individual PDE5 inhibitor available to prescribe.
This is due to the fact that each oral PDE5 inhibitor (or ED pill) has slightly different pharmacological effects.
ED medications – how they work
Here is how the PDE5 inhibitors of Viagra, Cialis, and other ED pills work:
The penis only becomes erect as a result of sexual stimulation. Sexual stimulation results in the release of nitric oxide. This causes the dilation of the blood vessels to the corpus cavernosum, the body of the penis shaft. This is in turn assisted by the growing presence of cyclic guaosine monophoshate, usually abbreviated to cGMP.
Unfortunately for a lot of men, particularly as they get older, the presence of cGMP breaks down by the increasing presence of PDE5.
Sildenafil, Vardenafil and Tadalafil, active ingredients used in erectile dysfunction treatments such as Viagra, Cialis and Levitra, are PDE5 blockers or inhibitors. By reducing the effect of PDE5 present in aging men, these PDE5 inhibitors allow natural erections to occur.
These PDE5 inhibitors only come into play when the cGMP synthesis is present and active.
Viagra, Levitra and Cialis all require sexual arousal to work
Needless to say, Ed pills that employ these PDE5 inhibitors require sexual arousal to become active and their intervention noticed.
After sexual stimulation subject nitric oxide is emitted from neurological synapses adjacent to the penises corpus cavernosum. As a result there forms an accumulation of cGMP manufactured from Guanosine triphosphate (GTP). This results in the relaxation of the muscle tissue. This leads to an erection to the cavity being filled up with blood. PDE5 inhibitors prevent the breakdown of cGMP. Consequentially, erections to take place with greater ease.
ED pills that use PDE5 inhibitors as the active ingredient are becoming increasing competitive. These ED treatments utilise structures derived from cGMP. In the case of Viagra and Levitra their actual molecular structures are very similar.
In distinction to Sildenafil and Varenafil, Tadalafil, the active ingredient in Cialis, has a alternate chemical structure. However, it retains the principle characteristics needed for the retardation of PDE5.
The differences in chemical structure can be viewed with the pharmaokinetic characteristics inherent in the PDE5 inhibitor Tadalafil. Also, how it interacts with various PDE isozymes and needs attention in an ED pills comparison.
Chemical characteristics of oral PDE5 inhibitors (ED pills)
PDE isozmes have been identified in 11 separate instances. They have been classified according to their amino acid sequence as well as their sensitivity to inhibition. Lab-based research has indicated that the oral PDE5 inhibitors retard PDE isozymes differently.
By and large all phosphodiesterase type 5 inhibitors used effectively suppress PDE5. Nevertheless, the three PDE5 inhibitors that form the basis of this study, Viagra, Levitra and Cialis, have different characteristics when it comes to inhibiting other PDE isozymes.
Selective inhibition of PDE6 and PDE11
Viagra and Levitra can cause vision distortion but not Cialis
Of the 3 PDE5 inhibitors discussed, some also a show propensity to retard the uptake of PDE6, an enzyme that has a factor in controlling the reception of light to optic nerves.
This inhibition of PDE6 affects the perception of color among subjects. It is often described as a bluish tinge. Studies in the laboratory indicate that Viagra and Levitra can result in retardation of PDE6 and as such introduce a slight distortion of vision.
Cialis does not show a similar propensity for PDE6 inhibition.
Studies have shown that Vardenafil has a threefold predilection to inhibit PDE5 over PDE6. Sildenafil has a sevenfold bias to retard PDE5 over PDE6. Tadalafil on the other hand has a seven-hundred-fold prediction to block PDE5 over PDE6.
Tadalafil has a greater predilection to inhibit PDE11 over both Sildenafil and Vardenafil. The function of PDE11 is unclear however.
The body absorbs oral PDE5inhibitors (ED pills) such as Sildenafil, Tadalafil and Vardenafil quickly into the blood stream after ingestion.
Viagra and Levitra achieve peak concentration and effects before Cialis
After ingestion, Viagra reaches a top concentration slightly less than an hour, Levitra reaches its peak plasma concentration in approximately an hour. Cialis takes up to 2 hours to reach its greatest plasma concentration.
ED pills comparison – The effect of food and alcohol
High fat food present in the subjects stomach prior to ingestion slows down the absorption of Levitra and Viagra. It appears to have little if any effect on the absorption of Cialis.
Effect of Viagra and Levitra reduced by fatty food content
High-fat content delays the absorption of Viagra by 1 extra hour. The peak concentration in the blood stream is decreased overall by 30%.
Similar to Viagra, high fat content slows down the uptake of Levitra for up to 1 hour. Likewise, the peak plasma concentration is reduced by around 20%.
Cialis unaffected by fatty food intake
On the other hand, the presence of fatty foods do not affect Cialis. One can take Tadalafil with little concern over stomach contents as the effects are constant.
The consumption of alcohol doe not seem to affect all 3 oral PDE5 inhibitors, Cialis, Levitra and Viagra. However, excessive consumption of alcohol remains a factor in erectile dysfunction incidents.
next: ED Pills Comparison part 2 – Viagra vs Cialis vs Levitra