In August 2003, Levitra became the second oral medication for the treatment of erectile dysfunction to be approved by the Food and Drug Administration for sale in the United States.
It got the American drug regulatory agency’s approval a little more than five years after the first such drug — Viagra — got the go-ahead in 1998.
Levitra’s active ingredient is vardenafil hydrochloride, which like the sildenafil citrate in Viagra belongs to a family of chemical compounds known as PDE5 inhibitors. These drugs are so called for their ability to temporarily sideline an enzyme known as phosphodiesterase-5. For men whose impotence is caused primarily by insufficient blood flow to the penis, the PDE5 inhibitors can significantly optimize penile blood flow for periods ranging from four to 36 hours.
Other PDE5 Inhibitors Followed
In the years since the introduction of Viagra and Levitra for the treatment of erectile dysfunction, a handful of other PDE5 inhibitors have followed them to market. These include tadalafil, the active ingredient in Cialis, approved in November 2003; Staxyn, an innovative formula of vardenafil hydrochloride that dissolves in the mouth and was approved in June 2010; and avanafil, the active ingredient in Stendra, approved in April 2012.
As this is written, all of these ED drugs are available in the United States only in their brand name formulations, but things will begin to change at the end of 2017 when a generic version of Viagra is scheduled to be introduced on the U.S. market. The patents on both Cialis and Levitra are scheduled to expire in late 2017 and 2018, respectively, although Cialis’s patent holder is seeking to extend its market exclusivity until 2020 and is involved in litigation to postpone generic competition.
Bayer Holds US Rights to Levitra
Originally co-marketed jointly by Bayer HealthCare Pharmaceuticals, GlaxoSmithKline, and Schering-Plough in markets around the country, Bayer now holds exclusive rights to Levitra on the American market.
Prior to the introduction of Viagra and the other PDE5 inhibitors that followed, it was widely believed that most erectile dysfunction was caused by psychological factors, such as anxiety and depression. It is now recognized that in fact the vast majority of ED is caused by insufficient blood flow to the penis. It’s estimated that impotence of psychological origin accounts for only 10 to 20 percent of all ED cases.
Although each of the PDE5 inhibitors differs slightly from the others in its chemical makeup, they all work in much the same way. To fully understand how they work, it’s useful to know a bit about the basic mechanics of erectile function.
Erection Process Explained
Erections begin in the brain when that control center for the body’s nervous system detects feelings of sexual desire or physical stimuli to the man’s penis or other erogenous zones. Once the brain is primed to facilitate sexual arousal, it sends a flood of nitric oxide coursing through the body toward the male genitals.
On its way, this nitric oxide triggers secondary chemical reactions, one of which stimulates the production of a substance known as cyclic guanosine monophosphate, or cGMP. The cGMP in turn signals the soft muscle tissue that makes up the inner lining of arteries to relax, thus temporarily dilating the blood vessels and sharply increasing blood flow, which is necessary to create and sustain an erection.
Unhealthy Lifestyle Choices Can Lead to ED
Men whose vascular systems have been compromised over the years by unhealthy lifestyle decisions — smoking, lack of exercise, heavy intake of fast foods — may find it difficult to get and keep an erection because of diminished blood flow.
The PDE5 inhibitors, as explained earlier, give men with impotence of vascular origin a helping hand by temporarily disabling the PDE5 enzyme, which breaks down cGMP, thus impeding the upsurge in blood flow needed to get and keep an erection.
Levitra Is Not a Cure
Although the PDE5 inhibitors, such as the vardenafil hydrochloride in Levitra, have helped millions of men to temporarily regain normal or close to normal erectile function, they are not a cure. Once their effects wear off, which varies depending on the specific medication, blood flow to the penis again diminishes and getting an erection once again becomes difficult, if not impossible.
Clinical testing has found that while the vardenafil hydrochloride in Levitra is effective and safe for most men suffering from vascular-related impotence, it is not for everyone. Doctors often counsel men with severe heart disease or advanced heart failure to avoid the physical stress required for sexual activity.
Incompatible with Nitrates
Others with angina or intractable high blood pressure are often prescribed nitrate-based drugs to treat those conditions. Nitrates and PDE5 inhibitors are totally incompatible. Because both sharply lower blood pressure to achieve their medicinal goals, taking them together could conceivably cause a potentially life-threatening drop in blood pressure. It should be noted that the recreational drugs known as “poppers,” often used in connection with sexual activity, are nitrate-based and should never be used with PDE5 inhibitors.
In common with most of the other PDE5 inhibitors, Levitra can cause some mild side effects, which often disappear altogether upon continued use of the drug. Such adverse effects include back pain, dizziness, flushing, headache, indigestion, and runny or stuffy nose.
More Serious Side Effects
Although rare, Levitra’s more serious side effects include a sudden decrease or loss of hearing or vision or an erection that lasts for more than four hours. If you should experience any of these more serious adverse effects, seek medical attention immediately.
Levitra, as well as all of the other PDE5 inhibitors now on the market, are available only by prescription. If you have a prescription from your doctor, you can take it to your neighborhood pharmacy to have it filled or you can opt instead to order the drug from a reliable online supplier, such as AccessRx.com.
Ordering Levitra from AccessRx
If you choose to order Levitra online from AccessRx, you can fax your doctor’s prescription or scan and email it along with your order.
If you don’t yet have a prescription, AccessRx can arrange an online consultation with a member of its team of licensed U.S. physicians. If the online doctor determines that you’re an appropriate candidate for Levitra or any of the other PDE5 inhibitors, he or she will authorize a prescription.
AccessRx, based in Tempe, Arizona, is a member of the Secure Medical family of online drugstores and sells only FDA-approved drugs that are sourced exclusively from licensed U.S. pharmacies. If the convenience and privacy of an online order appeals to you can get started by clicking this link to reach AccessRx’s Erectile Dysfunction page.