Did you know?
The name Viagra is probably also derived from an Indian word, Sanskrit
"vyaghra" (tiger), although it is also an amalgamation of Latin "vita"
(life) and "Niagara" (the waterfall), perhaps intentionally appropriate.
The name of the product resembles the Hindi word for "46", chhiyalis, sometimes
transliterated as chialis or cialis.
The history of Cialis cannot be discussed without mentioning Viagra
or Pfizer. The FDA's approval on March 27, 1998, lead both of these prescription
drugs, Viagra and Pfizer, to a ground breaking success in just the
first year of introduction as they sold drugs worth over a billion dollars.
However, things changed considerably for the two giants of erectile dysfunction
drugs when the FDA also approved Levitra in August 19, 2003, and
Cialis in November 21, 2003. In 1993 the drug company Icos began studying
IC351, which is a PDE5 enzyme inhibiter, and this is basically the process
through which the erectile dysfunction drugs work. In 1994,
Pfizer scientists discovered that Sildenafil Citrate, which is a white
crystalline powder that temporarily normalizes erectile function of
the penis by blocking an enzyme known to inhibit the production of a chemical
that causes erections, caused the heart patients that were participating in
a clinical study of a heart medicine to have erections. Although the scientists
were not testing the chemical compound IC351 for erectile dysfunction,
the compound seem to have a side effect which could potentially worth million,
if not billions. Soon Icos received its very first patent in 1994 on IC351,
and the clinical trials of phase I took place in 1995. In 1997, phase II clinical
studies began and Icos performed its first study on patients with erectile
dysfunction. Phase II lasted about two years, and after that phase III
began. In 1998, ICOS Corporation, and Eli Lilly and Company, commercialized
the drug for erectile dysfunction, and two year later, they filed a new drug
application with the U.S. Food and Drug Admisnistration for IC351, only difference
was that this time they decided to call the drug, Cialis. In May of
2002, Icos and Eli Lilly and Company reported to the American Urological Association
that the phase III tests show that Cialis works for up to 36 hours,
and one year later Icos and Eli Lilly and Company received the U.S. FDA's
approval for Cialis. One advantage that Cialis has over Viagra
is that Cialis works for up to 36 hours as compared to 4 hours for
Viagra.
