Sildenafil chemical structure
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Viagra

Sildenafil citrate, sold under the names Viagra, Revatio and (in the Indian subcontinent) Caverta, is a drug used to treat male erectile dysfunction (impotence) and pulmonary arterial hypertension (PAH), developed by the pharmaceutical company Pfizer. Viagra pills, intended to treat impotence, are blue with the words "Pfizer" on one side and "VGR xx" (with xx representing 25, 50 or 100, the dose of that pill in milligrams) on the other. more...

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History

Sildenafil, initially known as compound UK-92,480, was initially developed to treat angina pectoris (a form of cardiovascular disease). Phase I clinical trials suggested that the drug had little effect on angina, but that it could induce marked penile erections. Pfizer therefore decided to market it for erectile dysfunction, rather than for angina. The drug was patented in 1996, approved for use in erectile dysfunction by the FDA on March 27, 1998, becoming the first pill approved to treat erectile dysfunction in the United States, and offered for sale in the United States later that year. It soon became a great success: annual sales of Viagra in the period 1999–2001 exceeded $1 billion.

The name "Viagra", like many drug names, is a marketing invention. It was possibly inspired by the Sanskrit word "vyāghra", which means "tiger". The word rhymes with "Niagara" (Niagara Falls is a popular honeymoon destination and Niagara, being such an impressive cataract, evokes a sense of incredible erectile and ejaculatory strength). The sound of the word also suggests the words "vigor" and "virile".

Even though Viagra is only available by prescription from a doctor, it was advertised directly to consumers on TV (famously being endorsed by Bob Dole). Numerous sites on the Internet offer Viagra for sale after an "online consultation," a mere web questionnaire. The "Viagra" name has become so well known that many fake aphrodisiacs now call themselves "herbal Viagra" or are presented as blue tablets imitating the shape and colour of Pfizer's product. A mixture of Viagra and ecstasy, called sextasy, has become popular among rave partygoers. Viagra is also informally known as "Vitamin V", "the Blue Pill", and goes by various other nicknames.

It has been suggested that Viagra would lead to a marked drop in the demand for certain traditional remedies, such as tiger penises and rhinoceros horns and that the drug may therefore help to preserve these endangered species. However, this is unlikely in that these parts of endangered species are not only used to treat impotence. Rhinoceros horns, for example, are used as a treatment for high fever. Furthermore, since Viagra has not been shown to possess aphrodisiac properties, it is unclear that the natural remedies would compete with this new clinical drug.

Pfizer's worldwide patents on sildenafil citrate will expire in 2011–2013. The UK patent held by Pfizer on the use of PDE5 inhibitors (see below) as treatment of impotence has been invalidated in 2000 because of obviousness; this decision was upheld on appeal in 2002.

Mechanism of action

Part of the physiological process of erection involves the parasympathetic nervous sytem to release nitric oxide (NO) in the corpus cavernosum of the penis. NO binds to the receptors of the enzyme guanylate cyclase which results in increased levels of cyclic guanosine monophosphate (cGMP), leading to smooth muscle relaxation (vasodilation) in the corpus cavernosum, resulting in increased inflow of blood and an erection.

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Viagra or Starbucks?
From Ward's Auto World, 12/1/04 by Brian Corbett

Byline: Brian Corbett

The '05 Buick LaCrosse races down a quiet road in Petoskey, MI, known as the Tunnel of Trees.

A scenic route with tight turns, the sedan slithers past slower traffic and hugs the road. Leaves, blazing with color, tumble down as the LaCrosse speeds past.

This will show my age, but I've never driven a Buick like this. It's downright fun, which is surprising considering the car's platform is old enough to buy cigarettes.

But while General Motors Corp.'s attempt to massively overhaul its W platform (MS2000) to make Buick relevant to luxury enthusiasts is ambitious and impressive, the LaCrosse fails to smoke the competition.

LaCrosse replaces two Buicks - the Regal and Century - and it's considered the flag-bearer of Buick's intended evolution from the automotive industry's Viagra brand to the choice of the Starbucks generation.

Unfortunately, there is a little too much vanilla in my LaCrosse latte.

The car is fine, but fine is not a compliment. The combination of improved handling, self-effacing styling and an outdated engine probably is not enough to convince import drivers to turn in their keys, even with the LaCrosse's price advantage. Pricing begins at $23,495 for the CX, $25,995 for the CXL and $28,995 for the CXS.

The LaCrosse's ride is as smooth as merlot. The tuning for the front strut coil-over-spring and rear trailing arm/tri-link rear suspension is 80% new vs. the Regal/Century, and rebound dampers are four times larger (This is the same platform overhaul GM gave its Pontiac Grand Prix last year.)

The feedback remains relatively soft, but Buick's usual Gummi Bear ride is gone. Swaying in the corners no longer will cause seasickness, especially in the CXS, which features standard larger stabilizer bars.

The LaCrosse is more nimble than the nose-heavy Regal/Century due to the new aluminum engine cradle that replaces the heavier welded-steel unit. Steering slack has been hemmed in by recalibrated systems on the CX and CXL and by supplier Delphi Corp.'s computer-controlled electromagnetic Magnasteer system on the CXS.

There are two powertrain choices. The CX and CXL are equipped with the latest version of GM's pushrod 3.8L V-6. The 200-hp OHV engine has been around so long - since the 1960s - it's the senior-citizen discount in LaCrosse's lineup. A nice base engine to deliver at a lower price, but the markdown pales in comparison to youth.

GM's still-new 240-hp 3.6L DOHC V-6, standard with the CXS, provides the technology and refinement that may attract new, younger buyers. Throttle response is excellent. Either powerplant is mated to a 4-speed automatic transmission.

The LaCrosse is a decent effort but fails to lead its segment due to unexceptional exterior styling and relatively dated interior appointments. For instance, the burl wood trim might have been used as paneling in Greg Brady's attic bedroom.

Inside and out, the LaCrosse betters the Regal/Century, though.

But it lacks the panache of the Chrysler 300's sheet metal and the contemporary design of the Honda Accord's cabin. There are some sharp exterior cues, including the separated dual headlamps and a subtle pleat above each rear door handle.

It's borderline dashing, especially considering this is the car GM product chief Bob Lutz delayed by one year after saying the only positive attribute about the original LaCrosse was that it was on time.

But considering the gorgeous concept cars Buick has produced during the last several years, the LaCrosse is not up to scratch. Snoop Dogg will not be calling for one.

GM added cost and weight to the LaCrosse with various sound-deadening initiatives. As a result, the LaCrosse's cabin is vault-like. Buick says it wants to compete with Lexus - and interior quietness is one area where it legitimately is doing that.

The silence gives the Starbucks crowd an opportunity for a coffee-house chat, or an afternoon nap for older passengers.

COPYRIGHT 2004 PRIMEDIA Business Magazines & Media Inc. All rights reserved.
COPYRIGHT 2004 Gale Group

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