All ED medications are the same (Viagra, Cilias, Levitra)

Myth

Viagra (Sildenafil) was introduced in 1999 and was the first of a class of drugs known as phosphodiesterase 5 (PD-5) inhibitors. To understand what that means and how these new medications work (and why they can have different effects and side effects), it is important to understand how men achieve and maintain an erection.

An erection occurs when a man is stimulated by an erotic thought or sexual contact. The brain then produces nitric oxide. That leads to a series of chemical reactions in the blood vessels of the penis that results in 6 times the blood flow to the penis. An erection might last indefinitely if it weren’t for phosphodiesterases. They work at reversing the process; they are responsible for returning the penis to a relaxed state. Usually there is a balance between the chemicals that make an erection last as long as it is needed and the phosphodiesterases that work to “deflate” the penis. Usually, the balance is perfect and each does their job when they should. Men with erectile dysfunction would benefit from having the chemicals leading to the erection outweigh the actions of the phosphodiesterases that cause the penis to lose its firmness. That is what the medications for erectile dysfunction do; they block, or inhibit, the phosphodiesterases and let the forces giving a man an erection rule. The result is a firmer erection that lasts longer.

A very brief comparison of these drugs can be made by examining how they can be used (‘as needed’ for all four, plus daily for Cialis), the time it takes for them to work, the length of time they work, the restrictions on how they can be taken, the contraindications to their use, and their side effects.

Though similar, ED medications have different effects and side effects. Sildenafil, Viagra, and Levitra (Vardenafil) have relatively rapid onsets of action compared to Cialis (Tadalafil).

Sildenafil, Viagra, and Levitra can be effective in as little as 1 hour, while Cialis might not take effect for 2 hours, though for some patients these medicines can work more rapidly. Viagra, Sildenafil, and Levitra will be out of the body in about 6 to 8 hours, while Cialis can work for 24 to 36 hours.

Levitra works about as quickly as Viagra and Sildenafil, and lasts about as long. However, it can be taken with food (as long as it is not excessively fatty), which is an excellent option with obvious real world usefulness. The effect of Sildenafil, Viagra, or Levitra may not be needed beyond 6 or 8 hours, and any side effects they cause will fade rapidly as a medication leaves the bloodstream.

The differences people experience in terms of the effects or side effects can make one drug preferred over the others, depending on a person’s circumstance. Sometimes, a peculiar side effect might prevent a man from taking Viagra or Sildenafil but not Levitra. Another person might not be able to take Levitra (Vardenafil) because they are on a medication that might lead to a cardiac arrhythmia, one that would not occur if they used Sildenafil, Viagra, or Cialis.

How might choices be made? Consider two men.

One man might know sex will occur during the course of a weekend but cannot say when. A drug with a prolonged period of activity is far more important than how long it takes for it to start working. For him, tadalafil (Cialis). Also, Cialis can be taken in a low daily dose and for a solid subset of patients, this is preferred because the issue of timing disappears.

Compare this to a man who is able to predict when sexual activity will occur. A drug that works rapidly and leaves his system quickly thereafter would be perfect, as with Sildenafil or Viagra. If dining is part of the evening’s plan, Levitra may be a more practical choice, as it is unaffected by food and it too will be out of his system by morning. One restriction on the meal exists, however. It is not necessary to take Levitra on an empty stomach but a very fatty meal should be avoided when taking the pill. Fat interferes with its absorption after a meal where fat is more than 55% of the calories.

You may think that gives Levitra (vardenafil) a clear advantage over Viagra and Sildenafil for someone wanting to take a short acting tablet, but there is another important consideration. Levitra (Vardenafil) can cause an abnormality seen on EKG called QT prolongation or make long QT syndrome more pronounced. If that occurs, serious irregular heartbeats can follow. The list of medications that can cause QT prolongation is quite large.

One issue is rarely the sole factor when choosing a medication. It is the interplay between a man’s social circumstances and that of their partner, his need for a rapid onset of activity versus a long duration of action, the individual side effects, a person’s prior medical history, the other medications taken, and the very personal definition of what it means to achieve an erection satisfactory for sexual activity.

Viagra, Sildenafil, and Levitra leave the body in about 6 to 8 hours. That means that while they are very effective–approximately 75% of patients will achieve a satisfactory erection–they will work reliably only for 6-8 hours. Nevertheless, the effect of a medication may not be needed beyond 6 or 8 hours, and any side effects will fade rapidly.

Someone who experiences nasal congestion or flushing with Viagra, Sildenafil or Levitra (vardenafil) may find it an advantage to take the shorter acting medications, as opposed to Cialis. It might be worth a bit of nasal congestion during the time when sex will occur but there would be no reason to endure a stuffy nose 30 hours after sexual intimacy had concluded.

One other point about the Levitra versus Viagra and Sildenafil comparison. Levitra has one solid advantage over Sildenafil or Viagra, both of which can cause men to see a bluish tint. That is because Viagra and sildenafil not only affect phosphodiesterase 5 but also phosphodiesterase 6, which has a role in regulating the retina. Levitra has very little impact on phosphodiesterase 6 and significantly decreases the possibility of that side effect.

Again, it is never as simple as considering just one factor. There is a good deal of trial and error in finding the right medicine, the most effective dose, and the plan that results in the fewest side effects. Sometimes, a side effect is worth the benefit, sometimes not.

On occasion, a man will be on other medications that make a dose adjustment necessary. Even a simple antibiotic like erythromycin can alter how the body handles these ED medications. Grapefruit juice can do so, as well. Some medications lower blood pressure and each of these medications, Viagra, Sildenafil, Levitra, or Cialis, can add to that blood pressure lowering effect and be quite dangerous. Nitrates, nitrites, and nitroglycerin can all be dangerous when combined with medications that treat erectile dysfunction.

The key is to get educated and share all your information with each of your healthcare providers. Only by doing so can a safe, effective, and personalized treatment plan be crafted with your goals and your safety preserved.

There have been some studies comparing Viagra head to head with Cialis to see which is preferred by men and which is preferred by their partners. The study results are summarized below.