Comparing Cialis, Levitra & Viagra
If you watch television, you have probably heard all about Levitra, Viagra or Cialis. Although thousands of websites sell these products, many people don’t understand the exact role of these drugs. The mere names can be confusing so we’re doing to discuss more about each drug and their role.
Viagra
Viagra is the brand name for sildenafil citrate which is used to treat erectile dysfunction in men. Originally designed to treat heart disease or angina by Pfizer, the drug was discovered to enhance men’s erections. After the drug was patented in 1996, the Food and Drug Administration or FDA approved it in March of 1998. This prescription drug was the first erectile dysfunction drug available in pill form that the FDA approved.
How It Works
Viagra releases nitric oxide in the corpus cavernosum which increases the cyclic guanosine monophosphate levels by activating an enzyme called guanylate cyclase. This relaxes the muscles in the corpus cavernosum which in turn increases blood flow to the penis. This drug only works in conjunction with sexual stimulation and an increase in guanosine monophosphate levels. The drug will take effect in approximately 30 minutes and will last up to 4 hours.
Cialis
Cialis, the brand name for Tadalfil, first appeared in February, 2003. In November of that same year, the FDA approved this drug which was created to treat impotence or erectile dysfunction. Cialis is marketed by Lilly ICOS, a joint venture between ICOS Corporation and Eli Lilly and Company. The drug is available in pill form and available by prescription only. It is meant to be taken orally. Read the rest of this entry »
Viagra: The New Discovery It Was Not Designed To Treat Erectile Dysfunction
Viagra, the brand name for sildenafil citrate, proves that luck has just as much to do with the pharmaceutical industry as design. Companies spend huge amounts of money and employ millions of scientists in order to develop medicinally effective drugs that will cure all of our medical problems. Economics are as much a driving force as the desire to ease the pain of worldwide sufferers. Each time a new drug is discovered that can effectively treat a common ailment, huge amounts of money can be made.
Lead Compounds
During the past few decades, the pharmaceutical industry has made great progress. Chemicals can now be discovered to treat common diseases thanks to the study of disease pathways and advanced molecular design techniques. Lead compounds is the term for these chemicals, and they refer to molecules that play a role in treating a medical condition, but require additional research to lower the side effects or increase their efficiency.
Numerous Trials
Scientists who are searching for a viable drug take these lead compounds and synthesize them to form many similar compounds. Thousands of these compounds may be tried unsuccessfully before an effective treatment is eventually discovered. Most of the trials prove the compounds to be ineffective and the research unsuccessful. In fact, this nearly occurred to the compound we know as Viagra.
Hypertension Research
During the late 1980s, a research group from Pfizer was searching for a compound to treat hypertension. They were attempting to enhance the activity of a particular compound named “atrial natriuretic peptide” or ANP. A natural diuretic, this compound relaxed the blood vessel walls and caused the kidney to increase urine production. Therefore, a drug that enhanced this activity could be used to lower high blood pressure.
Angina
After studying the mechanism that caused ANP to work, the research team considered lead compounds that could reduce the activity of one enzyme group involved in the mechanism called phosphodiesterases or PDEs. They discovered lead compounds that inhibited PDE-5 activity that involved in the muscles of platelets and blood vessels. These compounds could potentially treat angina by increasing blood flow to the heart, as well as thrombosis or blood clots that are caused by platelets. Read the rest of this entry »