The three most popular male impotence drugs on the market for the treatment of erectile dysfunction are Viagra, Cialis and Levitra. All are similar in function, but there are differences apart from simply coming from different manufacturers.
Viagra - How It Works
Viagra is the brand name for sildenafil citrate, made by Pfizer. Approved in 1998 by the FDA for the treatment of ED, it has been used safely and with good results by millions of men since. It is taken in tablet form.
Erections occur when stimulation causes nerve signals to release hormones that cause the smooth muscle tissue in the penis to relax and engorge with blood. Viagra helps that process occur when some condition is interfering with it. It does so by blocking a chemical that would allow blood to flow out of those tissues. Increased blood retention by the tissues leads to greater stiffening.
Clinical studies show that nearly 90% of those using Viagra properly report improved ability to achieve and sustain erection. For most of those, it begins working in about half an hour and may continue to be effective for 2-4 hours. Given that the average sexual encounter lasts about 30 minutes according to surveys carried out by the National Opinion Research Center, that is plenty of leeway for most individuals.
What Is Cialis
Manufactured by the Eli Lilly company, Cialis is the brand name for tadalafil. It works in a way similar to Viagra, but the dosage is different. Prescribed dosages vary from patient to patient, with most taking either 5 mg, 10 mg or 20 mg. The average Viagra dosage is 50 mg, though 25 mg and 100 mg are available.
Like Viagra, Cialis works in about half an hour, but the effects may last as long as 36 hours after taking the pill. Clinical studies report that the drug is effective for about 78% of those who tried it. So, patients are trading the odds of slightly lower effectiveness with a longer lasting medication.
Does Levitra Work
Levitra is a product of Bayer Pharmaceuticals and is marketed by GlaxoSmithKline and Schering-Plough. It is a brand name for the drug vardenafil. As with Viagra and Cialis, it works by minimizing blood flow out of the penis. Studies show the tablet to be about 80% effective. Onset is within about an hour. Like Viagra, it works for up to about four hours.
All three drugs work in a similar way. Which one is best for an individual patient will depend, of course, on personal circumstances. Those will include medical history, symptoms or diagnosis for the underlying cause of their erectile dysfunction, age and general health, and other factors.
Those that are taking other medications, such as nitrate-based heart medications for example, should avoid Viagra. All three have a long list of potential drug interactions that need to be investigated on a case-by-case basis. All have potential side effects, such as interfering with blood pressure.
Depending on the underlying reason for the erectile dysfunction, patients will be cautioned about all three in different ways. Those that have recently had prostate cancer surgery will be treated differently than someone who has hypertension. A professional consultation with a physician is the best option.